A repository for the preservation of ice during warm weather; often a pit, with a drain for conveying off the water of the ice when dissolved, and covered with a roof. — Webster, 1882
The railroad company’s ice house is at this time being willed with a good quality of ice. -January 1884, Iroquois Herald.
Ice houses were only practicable in northern latitudes where water freezes to such a thickness and with such certainty as to make its harvesting profitable. In building an ice-house, there are two conditions to be considered: First, the cost of constructing the ice-house, and the cost of the ice to fill it. In localities where harvesting ice is expensive, it made sense to spend more money on a well-built and insulated ice-house. Where ice was comparatively inexpensive, it was more economical to build a cheaper but larger structure, and harvest a greater quantity of ice.
The Wilders’ ice-house was “built of boards with wide cracks between. It was set high from the ground on wooden blocks, and looked like a big cage.” (Farmer Boy, Chapter 6, “Filling the Ice-House”) According to Laura Ingalls Wilder, it took three days to fill. For the Wilders, ice was both plentiful and in close proximity. It cost only time and the wages paid to French Joe and Lazy John to harvest it.
Based on the surface-to-volume ratio, the most cost-effective shape for an ice-house was theoretically the sphere, followed by the cylinder. The most practical ice-house shape for the family farm, however, was the cube. The smallest practical dimensions were 10x10x10 feet; the greater the size, the more economical the ice-house would become in proportion to the amount of ice it held. A 10x10x10 house held 1000 cubic feet of ice (1000 blocks of ice, each a foot square); a cubic foot of ice weighs 57 pounds. Therefore, the weight of the entire ice-house of ice would be 40,000 pounds. (How much did Father Wilder’s 20-inch square blocks of ice each weigh?)
While you might think that under ground might be a good place for an ice-house — after all, didn’t the pioneers store food in an underground cellar to keep it cool? — earth is a great conductor of heat. While it might make sense to have an underground ice-house during a hot summer when the air is hot but the earth is a constant 47 to 52 degrees or so, in the north, there are over 200 days per year in which the air temperature is colder than this. In addition, the conductivity of the earth is over twice as great as that of air.
Like the Wilders’ ice-house, it’s best to raise the floor off the ground, to allow for water to drain away from the ice. But the floor must also be insulated from the warmer earth, from one to two-and-a-half feet of insulation was advisable. The material should be both light and porous in order to trap insulating air: sand, crushed stone, or cinders. Sawdust, which the Wilders used, was not highly recommended because it both decomposed and compacted when wet. Almanzo and Royal’s tight packing of the sawdust perhaps did more harm than good! The drawing above, however, comes from THeron L. Hiles’ The Ice Crop: How to Harvest, Store, Ship, and Use Ice (New York: Orange Judd Co.), 78. It shows an ice house packed with ice blocks insulated with sawdust.
Although Laura Ingalls Wilder doesn’t say so, it’s possible that the Wilders’ ice-house had its board sides both battened and sided. The open construction, however, suggests that the Wilders relied on a larger quantity of ice and saved on the cost of construction of a better-insulated storage facility.
If you want to play with perfect ice cubes and don’t have a nearby pond, a cross-cut saw, or hired help that will work for wages paid in salt pork, purchase some “perfect cube” silicone ice trays. A few seconds under the tap, a little freezer time and some sawdust, and you can fill your own miniature ice-house.
ice-house (FB 6, 9, 18)