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Cold Comforts: Natural Refrigeration in the 1632 Universe
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In Walden Pond, Henry David Thoreau declared, "it appears that the sweltering inhabitants of Charleston and New Orleans, of Madras and Bombay and Calcutta, drink at my well." What he meant by this was that the ice cut from Walden Pond would travel, in Boston ships, to those far off places, and be used to chill drinks.
Mark Huston, "Refrigeration and the 1632 World: Opportunities and Challenges" (Grantville Gazette 8) addressed the prospects for artificial refrigeration in the 1632 universe. It will happen, and it will happen a lot sooner than it did in the old time line (OTL), but it will not happen right away and it will not happen everywhere at once. For one thing, all the appropriate refrigerants are in short supply, and those which are most readily available are also rather dangerous to use.
A short-range snow and ice trade existed before the Ring of Fire, and a long-range trade sprang up in the nineteenth century and was quite profitable. I believe that there will be a window of opportunity in which it can prosper in the new time line until it is finally eclipsed by modern refrigeration. Bear in mind that the same body of up-time knowledge that makes artificial refrigeration possible also enables the building of steamships and railroads, which will minimize the time necessary to transport ice over a great distance.
While the principal purpose of this article is to explore the possibilities for long-range trade in natural ice, what is said here concerning ice storage, transport and use applies to manufactured ice, too. And the discussion of insulation may be of more general interest; it's relevant to protection of temperature-sensitive electronics, chemical reactors, and liquefied gas storage.
Culinary Uses of Ice
There are four basic culinary uses of ice: short-term chilling of food and drink to make it more palatable; long-term refrigeration, to preserve it from spoilage in storage or transport; incorporation into frozen desserts; and temperature control during brewing.
Chilling. Chilling drinks was probably the most common seventeenth century use of snow or ice; Francesco Redi wrote (1685), "Snow is good liquor's fifth element"—its quintessence. (Redi 17).
While snow or ice could be put right into a wineglass, the ancient Romans favored putting it into a kind of strainer suspended in the vessel, so it wouldn't be drunk along with the wine. Of course, it would still melt and dilute the beverage, but the Romans didn't usually drink wine straight, anyway.
The alternative was to put the wine inside a larger vessel, filled with ice; a "wine cooler." This principle could be inverted; the Grand Duke Cosimo of Florence, in 1570, had several large (25-28 pound) silver wine coolers that had an inner vessel that held snow. (David 5).
The Italians leaped from using frozen water to chill food and drink for the table to using the ice as a form of decoration. Beginning in the 1620s, fruit, ice, salt and water were placed in pyramid-shaped pewter moulds to form ice pyramid centerpieces. (David 38ff, 58ff).
John Barclay, a Scotsman resident in Rome, wrote the romance Argenis (1621), set in Mauretania, which spoke of ice-encrusted apples and wine goblets made of ice. It's clear that this was based on observation of the Roman table, since Antonio Frugoli of Lucca reported (1631) that at the feast of the Assumption on Aug. 15, 1623, there was un monte di diaccio con diversi frutti dentro, an ice mountain with fruits frozen inside it. If an ice mountain wasn't spectacular enough, the centerpiece was an icy volcano; it spouted orange flower-perfumed water for over half an hour. This signifies not merely an ability to preserve natural ice, but to artificially freeze liquid water inside a conical mold with an inner tube to serve as the "volcanic vent." Artificial freezing was also necessary to make the ice bowls and dishes described in books published by Florentine stewards in 1669 and 1672, and possibly describing a practice dating back to our time period. (David 55-65).
Food Preservation. To stop bacterial action completely, you need to freeze the food, and ice alone won't accomplish it. However, ice-based refrigeration slows down bacterial action and can keep food fresh for a week or two, assuming that it brings the temperature down at least to 40oF.
In the Far North, the Inuit are well aware that food can be frozen for later use. In winter, "fish froze whole within a few seconds of being removed from the water." If they were caught around freezeup (September-December, with freshwater freezing sooner), "whole fish were often placed on a gravel bar to freeze overnight, and then thaw again the following day." (Burch 146). For that matter, Inuit have been known to eat frozen mammoth meat. The Dolganes of Siberia pack fresh bear and reindeer meat into snow and come back for it when ready to eat it. The Lapps eat poronkaristys, sauteed reindeer, fat-fried slices of frozen reindeer meat. (Shephard 281-2).
The Russians, certainly, were familiar with frozen food. William Coxe's 1787 Travels described (2:300) the "frozen market" of Saint Petersburg, and Murray's 1838 Handbook for Travelers said that similar markets were held in all the large cities. John Bell's 1763 Travels said that Astrakhan fish "caught in autumn are carried to Moscow frozen," and Jonas Hanway's An Historical Account of the British Trade over the Caspian Sea (1753) said that fish are "sent either salted of frozen to distant parts of the Russian empire" (141).
Further south, European down-timers are aware that meat can be preserved by cold; Francis Bacon died in 1626 as a result of traipsing about collecting snow for an experiment testing how long it would preserve a chicken. However, outside Russia and Scandinavia, they made no systematic practical use of this knowledge.
Brewing. Beer is made by fermenting a malted grain (typically wheat or barley), in water flavored with herbs (a variety were used in the seventeenth century, but nowadays hops is standard). The beer yeast converts the sugars in the grain to alcohol, producing carbon dioxide gas as a byproduct. "Top-fermented" beers are produced in open vessels, at around 20oC (68oF), and stored for a few days or at most weeks at normal cellar temperatures. (Cannavan).
Even with top-brewed beers, temperature control would be desirable. "When the weather was hot and sunny it was possible that fermentation would run out of control." (Sambrook 155). "The first recorded use of a thermometer in a brewery was in 1758. . . ." (Blocker 94).
Conventional wisdom is that before refrigeration, brewing was seasonal, avoiding summers. However, the reality is more complex, at least for top-fermented beers. In Derbyshire, England, at Calke Abbey, during 1834, ale was produced only October through May. Beer was produced throughout the year, but summer brews were smaller and less frequent. Whereas at Lilleshall and Trentham in 1646–7, the peak production was June for strong beer and September for weak. (Sambrook, 155ff).
Lager yeast (S. pastorianus) flocculate to form large dense clumps that settle to the bottom of the vessel, and is active at colder temperatures than are the top-fermented ale yeasts (S. cerevisiae). They have an optimal growth temperature of about 28oC, a maximum growth temperature of about 34oC, and a minimum growth temperature of about 7oC. They are traditionally employed at 7–15oC in order to "develop specific flavor characteristics."
In contrast, ale yeast forms loose clumps that trap carbon dioxide, and thus rise to the top of the tank. Ale yeast has an optimum growth temperature that is above 30oC, and a maximum growth temperature of 37.5–40oC. Most will not grow below 15oC. They are usually used at 18–25oC. (Essinger 123; Robert 349–50).
Supposedly around 1420, brewers in the Bavarian Alps "discovered that beer lost its natural cloudy appearance when stored in mountain caves. . . ." This discovery gave rise to the lager style, "bottom-fermented" beers, which are fermented at about 8oC (46oF), "with as little air-contact as possible and cold-stored for as long as possible (six months was once considered the minimum . . .)." (Cannavan).
With Alpine caves at their disposal, these Bavarian brewers didn't have to worry about refrigeration. Their lager was winter-brewed and winter-stored, however.
When lager became popular outside of Bavaria in the late 1830s, the brewers had to harvest or buy natural ice from lakes or rivers and store it. (Blocker 94). In 1880s America, the brewers were the biggest customers of the natural ice companies, and sometimes cut and stored their own ice. Dissatisfaction with the seasonality of the natural ice supply, and the occasional ice crop failure, led them to be among the first adopters of artificial refrigeration (see "Competition" section).
Frozen Desserts. A dessert, by definition, is sweet, and therefore contains some kind of sugar. The source of the sugar could be fruit juice, wine, honey, sugarcane, sorghum or sugar beet.
Frozen desserts include sherbets, water ice, ice cream, ice milk, and sorbets. FDA defines a sherbet as a food produced by freezing, while stirring, a mixture of a fruit juice (or certain other sources of flavor and sweetness) and dairy ingredients, the resulting milkfat content being 1–2 percent. (37 CFR 135.140). A "water ice" is similar except that it contains no dairy ingredient except egg white. (135.160). And "ice cream" is similar except that it contains at least 10 percent milkfat. (135.110). In-between sherbets and ice creams, we have low-fat ice cream, also known as ice milk. The term "sorbet" doesn't have a legal definition, but it's often used as equivalent to "water ice." The term "milk ice" is sometimes used to cover all the frozen desserts in which milk is incorporated.
The use of the terms "sorbet," "sherbet," and "ice cream" in historical literature is quite different than the modern usage. For example, in sixteenth-century France, a sorbet was a beverage, a sweetened fruit juice diluted with water. (David 46). A Turkish sherbet of the same period might be ice-diluted, and a European copy might be ice-cooled, but that doesn't mean that either was frozen. Likewise, you cannot assume that a product called "ice cream" was one in the modern sense unless you actually can read the recipe and see that milk was used.
There are plenty of entertaining legends about the origin of ice cream (milk ice). There is some evidence of frozen milk products in early China, but it didn't seem to have much impact on seventeenth-century Chinese culinary practice, let alone what Europeans ate. I think it unlikely that the Arabs—even the "Caliph of Baghdad"—ate ice cream, although they certainly enjoyed flavored and sweetened water ices. There's no doubt that Italy was the first European country to enjoy ice cream, sometime after chemical freezing methods (see below) became known there, and it's possible that milk ice was available there before the Ring of Fire (RoF). Ice cream was first served in Britain in 1671, at Windsor Castle (Durant 172). Ice cream reached France sometime before it reached Britain.
Non-Culinary Uses of Refrigeration
One of the earliest non-culinary uses of ice (and ice water) was to bring relief to fever victims. (Visser 290). This prospect, in fact, was the key selling point that permitted Frederick Tudor to obtain a monopoly for the sale of ice to the British Caribbean (Weightman 46). Ice could also be used to minimize swelling and inflammation.
The main limitation on the use of natural ice for non-culinary refrigeration is that natural ice alone can only bring temperatures down to the freezing point of water; it cannot achieve colder temperatures as can a mechanical system. However, one can use chemical refrigeration (freezing mixtures) as discussed in a later section to achieve moderate freezing.
In the OTL, air conditioning of homes, workplaces and vehicles made hot summers more tolerable. It would require enormous quantities of ice, but conceivably natural ice could be used to cool air in ventilation systems. This would be somewhat similar to its use in the late-nineteenth and early-twentieth centuries on refrigerated rail cars. It would probably only be practical, if at all, in municipalities with excellent rail or water connections.
Likewise, ice can be used to cool chemical reactors. This is actually still done, on a small scale; a laboratory might use an ice bath to slow down a reaction, to reduce the vapor pressure of a volatile substance, or to alter the equilibrium of an exothermic reaction in favor of the products. Salts can be added to the ice bath to achieve colder temperatures. Ice might also prove useful in munitions plants, to reduce the temperatures at which the explosives are made and stored.
Refrigeration, possibly with natural ice, might also be used to remove (by condensation) moisture from the compressed air used by a blast furnace.
At least in the Far North, ice blocks can be used in construction, as evidenced by the Inuit igloos. Russia had the first known "palace" made of blocks of ice, constructed for Anna Ivanovna in 1739–40 (Wikipedia/Ice Palace). For serious construction, we will want to take a look at some form of pykrete. It's uncertain whether it's in Grantville literature, but there are certainly books on WW II in town, and one may have passing mention to the proposal (Project Habbakuk) to construct an aircraft carrier using ice reinforced with wood pulp, with the ice integrity maintained by artificially refrigerated brine pipes. Pykrete strength was about 7600 psi, half that of 1940s concrete. (Wikipedia/Pykrete). Additional strength could be achieved with better reinforcement (see my polymers and composites article), and insulation could be added, but it is probably wise to limit even a super-pykrete to the higher latitudes.
Trade in Ice and Snow Before RoF
The snow and ice trade is an ancient one. The Bible speaks of the refreshing nature of the "cold of snow in the time of harvest." (Proverbs 25:8, 13). Snow certainly wouldn't have been lying on the ground of Judea in the fall, so this was snow saved from the previous winter.
Generally speaking, those southerners, whether in southern Europe or in Asia, who had the advantage of living reasonably close to mountains that were snow-capped in winter, could enjoy chilled beverages in summer—if they could afford to pay for this privilege.
China. A poem written around 1100 BC states, "In the days of the second month, they hew out the ice. . . in the third month, they convey it to the ice houses which they open in those of the fourth. . . ." (David 228). I don't have any specific information about Chinese ice harvests in the seventeenth century, but in the eighteenth century, the British East India Company became aware that Chinese fishermen and fish merchants had above-ground ice houses and used ice to preserve fish. The ice, in turn, came from rice paddies deliberately flooded during the winter. (229ff). Ice could also be heaped outdoors and covered with several feet of clay. (243).
India. The ice used by the Mughal emperors could be manufactured chemically (see later section), or harvested from natural sources. Beginning in 1586, natural ice was brought to Lahore, the new Mughal capital, from the mountains, about 100 miles away. It could be transported by barge, carriage or bearers. The Ain-i-Akbari reports, "all ranks use ice in summer, the nobles use it throughout the year" (Mubarak 56). It was about five times as expensive during the monsoon heat as in winter.
The price in Akbar's time was as low as five copper dams (from which coin we reportedly get the expression, "I don't give a dam(n)") per ser (637.74 grams). At the time there were 40 dams to the rupee, so that's one-eighth rupee. In 1873 Calcutta, American ice sold for the same price! (Mubarak 56).
EB11/Ice provides information about nineteenth-century Indian practice (but I would suspect that the practice was already centuries old): "In the upper provinces of India water is made to freeze during cold clear nights by leaving it overnight in porous vessels, or in bottles which are enwrapped in moistened cloth. The water then freezes in virtue of the cold produced by its own evaporation or by the drying of the moistened wrapper. In Bengal the natives resort to a still more elaborate forcing of the conditions. Pits are dug about 2 ft. deep and filled three-quarters full with dry straw, on which are set flat porous pans containing the water to be frozen. Exposed overnight to a cool dry gentle wind from the north-west, the water evaporates at the expense of its own heat, and the consequent cooling takes place with sufficient rapidity to overbalance the slow influx of heat from above through the cooled dense air or from below through the badly conducting straw."
This was an extraordinarily labor-intensive process—two thousand laborers might hope to collect 25–30 tons in one night (Wightman 143)—but beggars couldn't be choosers.
Persian Empire. In mid-fifth century AD, a member of the Chinese diplomatic mission observed that in Ctesiphon (near modern Baghdad), "families keep ice in their houses." (David 199). Persian methods of producing and storing ice varied from region to region. In some places it was practical to bring snow and ice down from the mountains, and in others they had to make it locally.
In 1620, according to the Marquis Pietro della Valle, ice was made in Izfahan by creating conditions in which water could freeze outside. They dug a long trench and built a three-sided shade wall around it, so the trench was exposed only to the north. The wall protected the trench from the wind as well as the sun. Beyond the trench, in the plain to the north, they dig many small, shallow channels. They flood the channels, which froze over at night. In the morning, transferred the ice from the channels to the trench. Water was poured over the old ice in the trench so the new ice would fuse to it. (David 191ff). The trenches were covered with reeds during the day. (208) Come summer, the ice was broken with pickaxes, and sold in shops or by street vendors. The practice continued throughout the seventeenth century, as attested to by the reports of Jean de Thevenot (1650s–60s) and John Chardin (1670s).
Ice was cheap. Chardin notes that ice was sold by the donkey load, for effectively two deniers a pound. If a French denier had the same value as a Dutch denier—1/120 of a guilder—its purchasing power was probably about a third of a dollar in USE currency. Jean-Baptiste Tavernier, after returning from Persia in 1670, stated that there were charities, funded by bequests, that sent workers into the street with ice and water to provide it free to anyone who asked for it, and Chardin said that the wealthy would have ice water placed outside their homes for the convenience of passers-by. (212).
Despite the availability of this manufactured ice, some consumers preferred mountain snow for their drinks, and that too was available at the bazaar. Doctor Fryer reported that in 1676, even the poor would spend part of their money on snow.
If you were traveling, you could bring ice with you, or purchase it in a caravanserai (which probably had its own yakyal (ice house) and ice production facility). At Merv, in Turkmenistan, one can find the ruins of a fifteenth-century ice house in the shape of a stepped cone, with a shade wall nearby, and I would assume that this house was either built above the trench or alongside it. (215). An ice house of this type was still in use near Sirjan in 1975. (208).
Ottoman Empire. In Jaffa, Syria, in July 1494, the captain of a Venetian ship was gifted with a large sack of snow. (David xiii). According to the traveler Pierre Belon, who visited the Ottoman lands in 1546–51, the Turks "gather the snow, filling certain houses [buzchane] constructed like vaults or else like a hillock of earth," and situated in a location sheltered from the sun, and the packed snow could last for two years without melting. (David 41).
I have not been able to locate any reference to seventeenth-century snow or ice collection for the benefit of the rulers of the Barbary Coast states, but snow does fall regularly in the Atlas Mountains. In the nineteenth century, snow was stored at the icehouse La Glaciere, for use in the summer in Algiers. (Strahan 402). But ice was also imported; in 1905, a ton of Norwegian ice sold for fifteen francs ($3).(I&R 9:236).
Pre-Ottoman Egypt. Snow was transported from Lebanon and Syria to Cairo in the thirteen and fourteenth centuries. (David xii). This took advantage of the existing postal system (destroyed by Timur in 1400), which employed relays of horses and camels. This implies that only small quantities, for the sultan and his favorites, were carried, but they were carried very quickly indeed. (David xii, James 523).
Roman Italy. Pliny complained about his effete fellow Romans who defied the natural order by using snow to cool wine in summer, and Seneca was in high dudgeon because his compatriots used ice as well as snow. ("Nothing is cold enough for some people," yada yada yada.) Martial says that the cost of the ice or snow could exceed that of the wine it was cooling. (Forbes 113ff). The extreme example of Roman indulgence in natural refrigeration was set by the Emperor Elagabalus; "one summer he made a mountain of snow in the pleasure-garden attached to his house, having snow carried there for the purpose." (Thayer).
Renaissance Italy. According to Cardinal Ferdinando Medici, in the 1570s, Italians packed snow into pits fifty feet deep, and twenty-five feet wide at the top. The pit was lined and covered with "prunings of trees and straw"; there was a wood grating three feet from the bottom to suspend the snow above a crude drainage space. (David xiii-xiv). In 1583, Ferdinando had a vaulted underground ice-house constructed at the Villa Medici, in Rome.
Apparently, Ferdinando Medici was not the only resident of Rome who fancied ice in summer. On July 24, 1571, he issued instructions "to the Rome chief of Police and all other personages of whatsoever rank or condition, giving notice that Ottaviano da Burrino, his muleteer, and the muleteer's boy, are bringing two loads of snow per day to Rome, are not to be molested in any matter whatsoever, nor the snow to be taken to any other place whatsoever, 'for it is for our use.'"
In 1581, Michel de Montaigne saw the pits at Pratolino, Tuscany, whose snow was delivered to Grand Duke Francesco Medici In 1598, the hydraulic engineer Bernardo Buontalenti, Francesco's Superintendent of Public Works, was granted a monopoly over the delivery of snow to Florence each summer. It carried a pension of 210 scudi and of course the opportunity for profit. The penalty for violating Buontalenti's rights was "a fine of twenty five scudi and two strokes of the rope." (David 15ff).
Until Buontalenti's time, the snow was carried down from the mountains; Florence is situated on the Arno river, and the Appenines are no more than twenty miles to the north. However, in 1603–5, he constructed several laghi (or peschiera) di diaccio, ice lakes. Presumably, these were artificial lakes that froze over in winter, providing a convenient source of ice. The ice, in turn, was transported to buca (or conserve) di diaccio, ice pits. It appears that the ice was harvested in late December. Buontalenti died in 1608 and the exclusive rights passed to Francesco Paulsanti.
Despite innovation in Florence, ice was carried by cart from the Lessini mountains in Friuli, to Verona, Venice and Mantua. (David 68). In Venice, John Reresby reported in 1657, "in summer the meanest person seldom drinks his wine without having it cooled either with ice or snow, which is preserved in places made for that purpose under ground, and sold publicly in markets." (Reresby 102).
In the Spanish-controlled Kingdom of Naples, snow was stored in either ice pits, or the natural caves of Monte Somma and Monte Mauro (David 68).
Spain. Pits for the preservation of snow were dug during the reign of Carlos III of Navarre. (David xii). In 1492, not only did Columbus sail the ocean blue, the last Emir of Granada surrendered his city to Columbus' patrons, Ferdinand and Isabella. The surrender was in January of that year, but Emir Muhammad XII may have remembered summers past in which he stood on a balcony of Alhambra and drank water chilled with snow from a mountain eighteen miles away, in the Sierra Nevada of Spain. (David 53). By a 1584 English account, the Sierras were "continually covered in snow." (54).
In the late-sixteenth century, "snow was in common use at the Court of Castille by their Majesties, the Princes and princesses, and all the great Nobles and Gentlemen and the common people who reside there." However, this was not then true in Seville, where Nicolas Monardes (1493–1588) penned his Tratao de la Nieve y del Bever Frio [Treatise on Snow and Cold Drinks] (1574).
The Iberian snow trade expanded, and snow was available in Seville, Valladolid, Toledo and Murcia by 1621. (David 53). In 1645, in Madrid, the right to sell snow was auctioned off.
France. During the reign of Henry III (1560–74), the French "began decorating their tables with carved ice sculptures, serving dishes atop piles of snow, and putting ice in their drinks." (Qinzio x).
That ice had to come from somewhere, and, according to Monardes (1574), ice was transported 180 miles, from Flanders to Paris. If that's correct, then it presumably is ice cut from ponds or rivers, because Flanders (northern Belgium) isn't mountainous. But David (43) suggests that perhaps it came ultimately from the Ardennes mountains.
England. It has been suggested that simple, unlined ice pits were used back in medieval times. The first documented icehouses in England were built by James I; at the Greenwich royal palace in 1619 and 1621, and at Hampton Court in 1625. (Durant 172).
The ice house constructed in 1660 by Charles II in Upper St. James (Green) Park inspired this 1661 verse by Edmund Waller.
"Yonder the harvest of cold months laid up,
Gives a fresh coolness to the royal cup,
There ice, like crystal, firm and never lost,
Tempers hot July with December’s frost''
Nonetheless, ice houses were a rarity in seventeenth-century England. According to David (xv), in seventeenth-century and even eighteenth-century England, "only the most wealthy could afford ice." David indicates that the ice houses were "expensive undertakings on account of the digging," but as we have seen, digging pits was hardly unusual. No doubt the brick added substantially to the cost.
In 1665, the Governor of Virginia, Sir William Berkeley, was granted "licence to gather, make and take snow and ice . . . and to preserve and keep the same in such pits, caves and cool places as he should think fit, saving the king's loving subjects liberty to make and preserve snow and ice necessary for their own proper use." (Visser 290). These pits, presumably, were the old-fashioned unlined pits, and thus cheaper.
Denmark. Frederick II had an ice-house at Elsinore; on a 1580 map, it looks rather like a tepee. (David plate 2). It was stocked with ice as early as 1564, and in that year, the crown engaged carpenters to make "ice-coffins." (284).
Russia. It might not seem that Russians had much reason to store ice, but in the 1830s, Georg Kohl said that "their short but amazingly hot summer would render it difficult to keep all those kinds of provisions which are liable to spoil, if their winter did not afford them the means of preventing the decomposition accelerated by heat." The first documented use of the term lednik (ice-house) was in 1482. (Molokhovets 41). In the sixteenth century, fish were salted, smoked or packed in ice. (Smith 10). A 1646 report on flood damage to a drink shop at Velikie Luki on the Lovat said that "the water poured over the ice-house and froze. . . ." (Smith 146). In the 1660s, "the Russian Tsar had fifteen ice cellars for storing meat and fish and more than thirty cellars for storing drinks"; the ice was changed each March. (Molokhovets 41). The archbishop's palace also had an ice-cellar; in the attempted robbery of the church treasury in 1663, the thieves "had already broken a tunnel through the floor from the ice cellar into the palace." (Michels 97).
Adam Olearus—who has appeared in 1632 universe canon—wrote in 1656 that the Russians "prepare ice-cellars, in the bottom of which they place snow and ice, and above that a row of kegs, then another layer of snow, and again kegs, and so forth. Over the top they lay straw and boards, since the cellar has no roof. Thus they . . . may have fresh and delicious beer throughout the summer—which is quite hot." (Tatlock 32).
In the nineteenth century, there was a small export trade in frozen fish. "Perch would be sent from Tsaritsyn or Uralsk to Berlin and Vienna in wooden boxes with handles, packed between layers of straw and ice." (Smith 270). Of fish exported from Astrakhan in 1897, 11% were frozen or packed in ice. (272).
Elsewhere in Europe. Monardes says that ice was also available in the Germanies, Hungary, and Bohemia.
However, despite all this interest in snow and ice, the fact remained that it was an essentially local trade. It was not until the nineteenth century that means were devised for routinely shipping ice across great distances.
Pre-RoF Freezing Methods
Natural ice is great for cooling down drinks, but it won't freeze them. For that, you need some sort of artificial refrigeration.
The Huston article said that Thomas Cullen's process was the "first refrigeration," by which he meant, the first artificial method of freezing a liquid. Evaporating water was absorbed by sulfuric acid, which meant that more water could evaporate. Evaporating requires heat and the heat came from the remaining water. However, there were chemical freezing methods known before Cullen, and indeed before the RoF.
In Bengal, the temperatures usually don't go below freezing, so they couldn't make ice by the Persian method. Prior to 1586, ice for Akbar's table was made by mixing Bengali saltpeter (potassium nitrate) with water. (David 246).
This works because potassium nitrate has a large positive heat (enthalpy) of solution (8,340 cals/mole, CRC 69th D122), meaning that it needs energy to dissolve ("endothermic solvation"). The heat has to come from somewhere, and so the salt takes it from the water. Common salt also has a positive heat of solution, but it's very small: 928 cals/mole.
Now, an important point: You aren't putting the saltpeter into the water that you're trying to freeze. Rather, you have a vessel within a vessel, one containing the water to be frozen and the other the freezing mixture. The temperature of the latter will drop, thanks to endothermic solvation, but it doesn't freeze itself because the salt also depressed the freezing point.
Giambattista della Porta of Naples, in the "cooking" section of his Magia Naturalis (1589), explained how wine could be frozen: "Put Wine into a Vial, and put a little water to it, that it may turn to ice the sooner. Then cast snow into a wooden vessel, and strew into it Saltpeter, powdered, or the cleansing of Saltpeter, called vulgarly Salazzo. Turn the Vial in the snow, and it will congeal by degrees. . . ."
Cornelius Drebbel, at the court of James I of England, demonstrated chemical freezing in 1620. The same year, Francis Bacon, in Novum Organum, wrote that "nitre or salt when added to snow or ice intensifies the cold of the latter. . . ."
The Machinery's Handbook has a table of freezing mixtures (24th, 2442) featuring combinations of snow or water with common salt, calcium chloride, ammonium chloride (3533 cals/mole), ammonium nitrate (6140) or potassium hydrate (sic, exothermic!), and stating the resulting temperature change. EB11/Calcium says that "a temperature of -55oC is obtained by mixing 10 parts of the hexahydrate with 7 parts of snow." It's only the hexahydrate that dissolves endothermically; anhydrous calcium choride releases heat when it dissolves. (Cal-chlor). A calcium chloride brine can be cooled down (mechanically, or by being outdoors in a cold enough clime) to temperatures cold enough to "flash freeze" food. (Shephard 305, 2002EBCD/"food presrvation").
Some old encyclopedias (e.g.,) have articles on "freezing mixtures"; New International Encyclopedia (1903) adds ammonium sulfocyanate (5400), ammonium nitrate, potassium sulphocyanate (5790), and sodium nitrate (4900) to our potential salts.
THE LONG-DISTANCE ICE TRADE
Sources of Ice
A square mile (640 acres) of ice, 12 inches thick, weighs 700,000 tons (Hall 1), and Thoreau was told that one acre of Walden Pond ice yielded 1,000 tons. So finding ice, per se, isn't difficult (if you're in high enough latitudes or altitudes for water to freeze), the problem is finding ice that's convenient to transport to consumers and yet is unpolluted.
The principal sources of ice were lakes and rivers. Ice is opaque if it contains many air bubbles, which scatter light, and porous ice melts more rapidly. So, as our characters will learn, they should prefer clear ice. As a result, they will prefer a deep, gentle river to a lake, and a deep lake to a shallow one; the current and the depth tend to result in a lower air content. (Hall 8). A strong current inhibits ice formation, however.
Ice can be made locally anywhere there's an adequate supply of drinking water and temperatures fall below freezing at night during the winter, as evidenced by Persian practice.
In the mid-nineteenth century, around Berwick-on-Tweed, a British center of salmon fishing, "local farmers . . . flooded fields for the purpose [of making ice] and . . . sold it for 5–10 shillings per tonne; for some years it was their most profitable crop." (Cushing 108).
The natural ice industry had its unpredictable aspects; "ice famines" could occur if the producing regions suffered an unusually warm or short winter. New York, normally a producer state, had to import ice from Maine and Massachusetts in 1870 (Hall 21), and in 1880 it even obtained 18,000 tons ice from Norway. (Hall 3, 27). In 1898 the Norwegian and German ice crops failed, and Britain imported ice from Finland. (Blain 11).
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New England (initially just Massachusetts, later Maine was also exploited) ice was exported all over the world, including Martinique (1805), Havana (1807), Charleston (1817), Savannah (1818), New Orleans (1820), Calcutta (1833), Rio de Janeiro (1834), London (1842), Marseilles, Madras, Bombay, Canton, Manila, Hong Kong, Batavia, Sydney and Yokohama. (Hall 2–3; etc.). In the 1880s, the Massachusetts ice companies could expect to harvest about 669,000 tons in a good year (Hall 23), and in 1880 the Kennebec region of Maine shipped out 890,000 tons. In the new time line, the French are taking over the British colony in Massachusetts, and conceivably could exploit New England ice. However, even early-nineteenth century New England had much more of an infrastructure (sawmills, ships, laborers) to support a long-distance ice trade than is the case in 163x.
The Hudson river region of New York, in 1880, had the capacity to store 2,800,000 tons.
In the 1632 universe, the French are expected to take over, forcefully, the Dutch colony of New Amsterdam, and that of course will give them control of the Hudson River.
In 1880, ice was harvested in Ohio, Illinois, Indiana, Rhode Island, Pennsylvania, New Jersey, Iowa, Minnesota, Michigan, Wisconsin, and even Kentucky, Tennessee and Missouri, but these areas weren't colonized by the Europeans as of 1635 in the new time line and hence they aren't useful as a source of ice yet.
Entrepreneurs still in the Old World will want to find European sources, if possible, and these are discussed below.
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Scotland was of importance as a source of ice for local fishermen, but while fish frozen with Scottish ice ended up on British tables, it doesn't appear that Scotland had a larger role in the ice trade.
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Jan Baptist Van Helmont (1579–1644) reported that whalers in Greenland water strengthened wine by freezing out the water. (David 326). It's not clear when the ice was first harvested for sale, but it's known that in the late-eighteenth century, ice was brought from Greenland to Hamburg, and Greenlandic ice was brought to England as early as 1815. (Id.) In 1832, a 500 ton load was valued at 950 pounds for duty purposes. The same year, a ship brought in 150 tons from Iceland and the Faeroes, but it was valued at only 200 pounds. (335).
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Norway proved to be a much more important competitor for New England. The Norwegian trade began, unsuccessfully, in 1822; Leftwich's ship arrived in London with all its ice melted. "By the turn of the century, Norway exported more than 1,000,000 tons of ice each year, which vessels going to Northern Europe, the Mediterranean, Constantinople, Africa and even as far away as India." Less than half of this went to England (Weightman 189); still, Norway held 99% of the English market.
Initially, the Norwegians harvested ice from the fjords, rivers and glaciers of its rugged west coast. However, "in many places the ice had to be carried on people's backs." Later, they switched to the lakes of the more heavily populated south and southeast coasts. The terrain was gentler and "ice-mining was an ideal part-time occupation for both the local farmers and the shipping crews. . . ." In addition, the local sawmills generated plenty of sawdust, an insulator. (Blain 7-8). It proved more convenient to create artificial lakes close to the fjords, on high points so ice could be slid down wooden inclines to the harbors, rather than rely on natural lakes further inland (9).
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Sweden, Russia and Finland played only a minor role in the ice trade with England, because ice in the Baltic tended to keep their ports closed for a couple of months after Norway's North Sea ports had opened. (Blain 12).
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In the nineteenth century, Russian Alaska exported ice to California. In 1852, "250 tons of Novo-Arkhangel'sk ice were sold to the California Ice Company at $75 per ton and shipped to San Francisco." (Black 264). Sitka proved to be an unreliable source, so in 1855 the Alaska Ice Company began harvesting ice from WoodyIsland. In 1852–9, over 7,000 tons were shipped from Alaska to points south (not just California, but also Latin America). As volumes grew, the price fell to $7 a ton. (Carlson 58).
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In the nineteenth century, after Norway, the largest producer of ice in Europe was Austria-Hungary, in particular the Vienna Ice Company. However, it serviced the German market, not Britain, and all I know is that in 1883–1885, it paid 20% dividends to its shareholders, but that it was liquidated in 1913.
Harvesting Ice
Timing is all. In the states at the southern border of the American "ice belt," such as Pennsylvania, Maryland, Ohio and New York, late in the season, ice might be cut as soon as it was six inches thick. Further north, the companies could safely wait most years for the ice to be ten to fifteen inches thick, and in Maine the preference was for it to be 20–30 inches. You didn't want the ice to be much thicker than that as it made it harder to handle economically. (Hall 8).
In Massachusetts, ice was harvested from January through March, when the ice had frozen to a depth of eighteen inches or more (Weightman 4). It was obtained from various Massachusetts lakes, including Fresh Pond, Walden Pond, Spy Pond and Wenham Lake. Fresh Pond alone could produce 90,000 tons annually. (Weightman 193). The ice companies bought the shoreline to establish ownership of the ice, but there were occasional boundary disputes.
In the nineteenth-century New England ice trade, at first ice was harvested by hand, using pickaxes and chisels to break it into large blocks, which were then cut further on shore using two-man saws. Or you could cut a hole in the ice with an axe, and then saw out a block.
The big breakthrough was made in 1825 by Nathaniel Wyeth; the horse-drawn ice plow. The horses wore spiked horseshoes, for better traction, and the ice plow was eventually refined so that as it cut its line, it also scratched out a parallel line at the right separation to mark the next line. When one set of lines was complete, a second set was drawn at right angles to the first. The ice was thus gridded with horse-drawn iron cutters, and the grooves were deepened until the blocks could be pried out with chisels, and transported to timber ice houses on the lakeshore. The size of the blocks was based on the intended destination of the ice; the further it had to travel, the larger the block. When the spring thaw arrived, wagons took the ice down to the docks, and off it went. (Weightman 5–6, 106ff). The only disadvantage of the horse-drawn ice plow was that "the ice had to be thick enough to support the weight of the horses and the men driving them."
As the ice industry matured, specialized tools were developed to suit its particular needs; "eventually there were about 60 different tools used in the ice harvest for preparing the ice surface, cutting the blocks, poling blocks to the shore, breaking blocks, and getting the ice into storage." (Howell Farm) That doesn't mean we can't make do with standard tools like axes and saws to get the industry going. But according to Hall (4), the tools, supplemented by steam power for lifting the ice into the ice house, increased the speed of cutting and storing by a factor of ten.
My information about labor requirements is somewhat indirect. For example, I know that in 1880, the ice houses of the Hudson River region had a capacity of 2,800,000 tons. With good ice, the houses are filled as a result of the efforts of 20,000 men and 1,000 horses, in ten to twenty days from when cutting began. (Hall 26). That implies that 7–14 tons can be cut and stored per worker-day, given an experienced crew with then-modern equipment. The wages paid were $1–1.50/day, and the cost of cutting and storing was 25–50 cents/ton. (27). Cooper (1905) says that if the winter was favorable and the haul isn't more than a mile, harvesting cost 25 cents/ton. If the house was right at the shore line, half that; if the winter marginal, multiply by 2–4 fold. (464).
In 1844, at WenhamLake in Massachusetts, the crop of 200,000 tons could be cut and stored in three weeks. "Forty men and twelve horses will cut and stow away 400 tons a day; in favorable weather 100 men are sometimes employed at once." (Macgregor 988). That's 10 tons/worker-day. Consistently, Thoreau in Walden Pond said that in winter 1846–7, 100 men could harvest 1000 tons in a good day.
Bear in mind that this productivity data was for the mature ice trade. Figure that novices with general purpose hand tools will be less effective. Ballard (173) comments, "In our early history [1826?], seventy-five tons was considered a good day's work. During the past summer [1890?], several of the crews have handled in ten hours, one thousand tons."
I am not sure how much of this harvesting technology will be known in Grantville. There is no reference to it in the 1911 Encyclopedia Britannica, probably it has a strong British bias and the British mostly imported ice. However, I have seen very detailed descriptions of the process in certain old encyclopedias, such as the New American Encyclopaedia (1872), the New International Encyclopedia (1918)("Ice industry"), and the Encyclopedia Americana (1919)("Ice Industry"). Some of the really old people in Grantville may have seen ice harvesting in their youth. But bear in mind that it became very uncommon after 1930.
Also, West Virginia is on the southern margin of the ice belt. For example, in the 1870s, the Kanawha River had more than six inches ice in only one of seven winters (Annual Reports, War Department). Lakes and ponds are more likely to freeze up, of course.
The best chance that someone from Grantville will have seen industrial-scale ice harvesting is on a visit to a living history farm that either still does it or has photos showing what it's like. One such location is the Howell Living History Farm in Lambertville, New Jersey. There's also the Longstreet farm in Holmdel, New Jersey, and the Wessels farm in York, Nebraska.
Thoreau's Walden Pondis more tantalizing than helpful. In the chapter "The Pond in Winter," he describes the activities of a crew of a hundred men armed with "sleds, plows, drill-barrows, turf-knives, spades, saws, rakes, and double-pointed pike-staff[s]. . . ." They divided the ice "into cakes by methods too well known to require description and these, being sledded to the shore, were rapidly hauled off on to an ice platform, and raised by grappling irons and block and tackle, worked by horses, on to a stack, as surely as so many barrels of flour, and there placed evenly side by side, and row upon row, as if they formed the solid base of an obelisk designed to pierce the clouds."
When looking for possible sources, be resourceful. A farm-scale ice harvest is described in Laura Ingalls Wilder's Farmer Boy (64ff).
You have the choice of harvesting slowly with a small work force or quickly with a large one, at least if you're in an area with a long winter.
If the ice is being stored for later distribution, then it should be packed loosely (perhaps 40–45 pounds/cubic foot), so that the blocks can be removed as needed. But if the ice is placed directly in the overhead ice room of a cold storage house, then it's packed as closely as possible (perhaps 45–50 pounds/cubic foot), and the blocks caulked together with chips, so it forms a solid mass. (Cooper 483, 490).
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Since Saint Petersburg wasn't built until 1702, it obviously wasn't getting ice from the Neva in our time period. Still, it's interesting to read Georg Kohl's description of how ice was harvested there in the 1830s, since the Russian and American methods were certainly independently developed. The crew cut an inclined plane into the ice, so floating blocks could be hauled up to the rim of the quarry. As in New England, the ice was grooved, first to lay out a rectangle, and then a grid was laid over the rectangle. However, the grooves were made by hand, with an axe. A trench was dug to detach the rectangle. With this completed, workers would line up along a groove and strike it with heavy iron crowbar simultaneously. After a few knocks, the stripe would detach and they'd move on to the next one. A single laborer could cut a single stripe along the cross-grooves into individual blocks. (David 296).
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What can go wrong? On the large scale, thaws and rains can melt the ice crop, and snow has to be shoveled or planed off. On the small scale, a worker can fall into the icy waters or be injured by an unexpected movement of one of the 200–400 pound blocks. Tools can be lost or broken.
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A potentially more dangerous means of obtaining ice was to chop it off an iceberg. In August 1819, Captain Hadlock of the brig Retrieve succeeded, but the enterprise was nearly a disaster. On the first attempt, his sailors had to take shelter from a sudden storm. On the second, the inexperienced iceberg hackers caused the iceberg to topple over and damage the ship. They pumped their way to Martinique, and I hope Hadlock thought that his $1,700 fee was worth the trouble. (Weightman 92). On the other hand, in the twentieth century a Dane stated that it was "quite customary to use iceberg ice for drinking water" and "if you know icebergs, you know which ones are going to tip around." (David 327).
In Sitka, an ice crop failure forced the Alaska Ice Company to cut ice from Baird Glacier (Carlson 58).
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A small-scale operator can avoid much of the labor of harvesting ice by setting out bins of water and allowing them to freeze overnight. The resulting ice blocks are then freed from the bins and stored.
Mass Ice Storage
In the late-nineteenth century USA, ice was usually cut in January-March and consumed in May-October. (Hall 6). That was, of course, in part because ice was needed most when temperatures were high. However, the ice was not shipped south as soon as it was cut. The very conditions that made it easy to harvest ice also made it difficult to transport it. Ice was therefore harvested in the winter and stored until spring. The waste during this storage period was typically 10–25%. The ice would then be shipped to a distribution center and stored again until it was sold. The typical total waste, from harvest until arrival in the hands of consumers, was 40–55%. (Hall 9).
Natural caves. Caves are cooler than the surface in summer, but warmer in winter; a great mass of earth and stone has thermal inertia, a fancy way of saying that it changes temperature only slowly, so cave temperatures are virtually constant year-round. The depth in meters at which the annual temperature change is only 1oC is 3.18 * natural logarithm of the temperature change at the surface; that works out as 10.8 meters for a 30oC summer-winter surface difference. The average cave temperature is primarily a function of latitude and altitude; temperature (oC) = 0.6 * latitude (degrees) -0.002 altitude (meters). (A cave will be cooler than this formula predicts if it has a snowmelt-fed stream running through it during the spring.) (Moore 27ff).
Some caves contain ice year-round; either they are at a high enough altitude so the average surface temperature is below freezing, or they are "cold traps." The latter have a bottle shape; cold air flows in during the winter and blocks the ingress of warm air during the summer, reducing the average temperature by about 10oC relative to the predicted value. Cold traps are usually lava caves.
Underground storage is probably more advantageous in temperate regions, which have cold winters and hot summers, than in the tropics, where temperature variation is small.
Artificial caves. In Italy, Buontalenti constructed the Grotto Grande for the benefit of the Pitti Palace, and used it for ice storage. In Francesco Redi's epic poem, Bacchus in Tuscany, Bacchus orders, "bring me ice duly, and bring it me doubly/Out of the grotto of Monte dei Boboli. . . . (Redi 18). It's likely that Buontalenti also made use of simple ice pits.
The traditional English icehouse was mainly underground, and lined with brick or stone (Weightman 15). With regard to the 1619 "snow well" at Greenwich, contemporary accounts state that it was a "brick-lined well, 30 ft (9.23m) deep and 16 ft (4.92m) in diameter, covered by a thatched timber house with a door." (Pastscape Monument 761486).
Above-Ground Mound. At Walden Pond, the ice-harvesters didn't bother to build an ice house. "They stacked up the cakes thus in the open air in a pile thirty-five feet high on one side and six or seven rods square, putting hay between the outside layers to exclude the air. . . . At first it looked like a vast blue fort or Valhalla; but when they began to tuck the coarse meadow hay into the crevices, and this became covered with rime and icicles, it looked like a venerable moss-grown and hoary ruin. . . . This heap, made in the winter of '46–7 and estimated to contain ten thousand tons, was finally covered with hay and boards. . . ." Despite the lack of a proper roof, it survived the summer of 1847 and indeed "was not quite melted till September, 1848." This was called "stacking."
Above-Ground Ice House
That ends the preview. Probably in the middle of a sentence. Sorry.