Walker’s freezer was included in my post on pictures of: 17 Freezing Pots, Sorbetieres, Ice Cream Makers & Freezers from 1751 to 1916. HERE; Ice Cream posts HERE; Ice harvesting HERE
"It is now [1828] forty-one years since my discoveries on the “artificial production of cold ” were first made public by their appearance in the Philosophical Transactions for the year 1787, and several succeeding volumes…
Understanding, a few summers ago, that a manufactory had been established for preparing ice-creams, as well without the use of ice, as with it; and likewise for making for sale an apparatus for the purpose, - I was induced to visit it. I examined the apparatus, – a very appropriate one for the purpose, anul likewise the freezing powder, which I instantly recognized to be the weakest in power of my various compositions for the purpose, but possessing the advantage of being readily recovered repeatedly for the same purpose with undiminished effect. This powder, by its taste and appearance, I found to be a mixture of salammoniac and nitre, which I was in formed was repeatedly recoverable in a fit state for refrigeration. I originally exerted every effort, in vain, to increase its power by the addition of a third ingredient, possessing like wise the advantage merely by evaporation to dryness, of being repeatedly recovered for the same use. This powder, as related in my original communications, consists of equal parts by weight of sal ammoniac and nitre. By way of test, I recovered it by evaporation twelve times, without any abatement of its efficacy, as originally stated.
It is unnecessary to enter into a description of the apparatus just mentioned, or the principle and mode of its application, especially as the whole is embraced in the following statement.
A circumstance occurred here (at Oxford) which occasioned the method to be put to the test of useful application. A confectioner, happening in a scarce season to be unprovided with natural ice, applied to me for assistance. I assured him that in the large way (as I have stated in my original communications) the best method was to freeze water first, and then to use the ice in the usual way for freezing creams. Accordingly an apparatus of large dimensions, of rather an oblong form, was made of tin (fitter for the purpose if cased with wood) consisting of channels so constructed that the water to be frozen should be subjected to the freezing mixture on both sides.
This, properly prepared, was placed in a cool cellar during the night, and early in the morning (the temperature in the open air in the shade in the day - time being above 80°) the ice was collected, which amounted to several pounds in weight. This ice, which was as limpid as the finest flint-glass, was applied in the usual way, and with the apparatus ordinarily used by confectioners for the purpose of freezing creams.
The manufactory alluded to is at No. 41, New Bridge-street, Blackfriars, London (late Patterson's), now Armstrong's.
I shall now present the immediate object of my present communication; viz. what I consider to be the best mode and fit test apparatus for cooling wine in summer, for freezing creams in the small way for private use, and likewise for freezing a small portion of water, merely as an experiment for public or private exhibition.
The drawing annexed (Plate VII.) is designed to represent on a small scale the construction and exact proportions of each freezing apparatus, and likewise the construction and form of the apparatus for cooling wine.
Fig. 1. is an apparatus for freezing water on the smallest scale…
Fig. 2. consists of an apparatus in one piece; viz. the vessel for containing the cooling mixture, and the cup or can (if I may so call it) for receiving the decanter...
Fig. 3. The apparatus for freezing creams, in which the freezing mixture is to act on both surfaces of the part containing it, as being more economical and expeditious, is not so simple.
This however consists only of two parts; viz. the vessel for containing the freezing mixture; and a cover, to which is attached, in the same piece (instead of a tube or cup as in fig. 1.), a concentric annular cavity or chamber, in which the prepared cream is to be frozen: this cavity, forming a circle within the vessel itself, is open at the top, as represented, and of course closed at the bottom, and reaching very nearly (as the tube in fig. 1.) to the bottom of the vessel: this secondary part, as likewise represented, fits close as in fig. 1. over the vessel containing the freezing mixture.
The proportions of the apparatus when together are thus: The outer space in width, two parts all round; the middle space, or that which contains the cream, one part all round; and the inner space three parts in width, - - this serving as a general scale of proportions for an apparatus of any size. The proportions for an efficient apparatus, as my own, may be: for the first space ten-eighths of an inch (one inch and one-fourth); for the second, five-eighths of an inch; and for the third space, fifteen-eighths, or rather two inches, making the width of the apparatus itself somewhat above five inches and a half; its height being equal to its width, a projecting rim at the bottom likewise to insulate it from the table.
It will be perceived that in the figure there are seven very small holes or apertures in the central part of this cover (one in the centre and six round at due distances), just sufficient for the escape of the air, to admit of the ascent of the freezing mixture in the middle part of the vessel. This apparatus is somewhat elevated at the top, or slightly convex, and the part in which the apertures are placed guarded by a shallow rim to prevent an accidental running - over of the mixture into the part containing the cream. This apparatus should be furnished (as expressed in the figure ) with an outer cover similar, but less elevated, to the one at fig. 2. Previously to use it will be proper to ascertain the quantity of liquid the apparatus will contain when together, and mark its height; like wise the proportion of the ingredients for furnishing a given quantity in measure should be known.
Thus, if the three salts are used (which I would recommend to a private individual, always doing so myself, although these cannot be recovered for future use, but being more efficacious than the two only) for each pint, small or old measure, will be required of salammoniac and nitre (each equal parts by weight reduced together into fine powder) six ounces, and of Glauber's salt, in clear crystals and dry, four ounces and a half, freely reduced to fine powder, or kept from the access of air, and in a separate parcel from the former; and water ten ounces, or enough to make up one pint in measure when added to the former ingredients: - of course, the whole must be well stirred together, and expeditiously, before introducing that part of the apparatus which contains the article to be frozen, and occasionally after wards, till the object is completed, avoiding as much as possible any accidental accession of heat.
A freezing mixture composed of salammoniac and nitre with water, all at the temperature of 50°, to which temperature, or nearly so, they may all be reduced by water from a pump by drawing off a sufficient quantity first, will from 50° produce a cold of 22° below the freezing point, and with the addition of Glauber's salt to 28°. The confectioners find a degree of cold at 12° or 15° be low the freezing point sufficient for their purpose; but it must be recollected that the cold produced by salts dissolved in water is not so durable as with ice and salt; the duration of the refrigerating power in the above mixtures will of course be in proportion to the quantity and thickness of the apparatus. In the way the confectioner managed, the mixture in the apparatus retained its freezing property till the morning: my usual way is, in extreme hot weather, to place the vessel containing the powdered salts in the coldest water drawn from the pump previously; but in the ordinary way it will suffice to add the cold water without the above precaution: it may be advisable to be provided with a second quantity of the ingredients to preserve the cold by a renewal of the mixture.
The drawings are taken from an apparatus of each kind of my own, — they are made of tin, for want here of a fitter material, and are painted out side of a grass-green colour. The confectioner above mentioned laid in a stock of a hundred weight of each of the articles; viz. sal ammoniac and nitre; the former at the rate of one shilling per pound, and the nitre at fourpence — which of course when mixed, was at the moderate price of only eight pence per pound. Glauber's salts may be procured in the large way at the rate of about twopence per pound, and by the single pound at fourpence. The apparatus above mentioned may be only half or three parts filled for use; care must be taken in every instance that the surface of the subject to be acted upon be rather below the surface of the freezing mixture.
Walker, Richard. "On the artificial production of cold." Philosophical Magazine v3 June 1828
Walker, Richard. "Experiments on the Production of artificial Cold." Read on June 5, 1788 in Letter to Henry Cavendish (1731-1810). Philosophical Transactions of the Royal Society. London: 1788 HERE
THIS WEEK'S TALKS
Jul 26 Tue 12 A Taste for Maize: More than Popcorn & Corn on the Cob! Three chefs “recipe demonstrations and share their culinary knowledge.” National Agricultural Library. 3 part series and TAPES HERE
Jul 26 Tue 2:30-4 The Festival of Lammas. Loaf-mass. “British and Irish festival that brought in the opening of the autumn season, with the grain harvest, was known in Ireland as Lughnasadh, in Wales as Gwyl Aust, and in England as Lammas.” Ronald Hutton. The Viktor Wynd Museum. Tape for 2 weeks. £10.00 HERE
Jul 27 Wed 1 Rome From Ancient Aqueducts to Baroque Fountains. Dr. Dimo Kosmopoulos. Context travel Conversations $26.50 tape HERE
Jul 27 Wed 6:30 Life Downstairs: British Servant Culture in Fact, Fiction, and Film. Ann McClellan. Derry Public Library HERE
Jul 28 Thu 12-1:30 Live from Kenya! Chapati & Blacksmithing. “Indian chapati was transformed by Kenya into something different. It is a lightly laminated dough.” The last remaining traditional blacksmith in the region; process includes dragging a magnet thro dry riverbed sand for iron ‘black sand.' William Rubel $5-20 (all to blacksmith) HERE
Jul 28 Thu 6:30 A Taste of Old Colony History. “It's tea time! This month we're making strawberry jam, scones, and clotted cream” Old Colony History Museum HERE
Jul 28 Thu 6:45-8:15 Good for the Land, Good for Us: How Farming Can Improve Human Health. David R. Montgomery, Anne Biklé authors of What your food ate. Smithsonian Associates $25 HERE
CALENDAR OF VIRTUAL FOOD HISTORY TALKS HERE
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