The works of the Honourable Robert Boyle, Esq., epitomiz'd by Richard Boulton ... ; illustrated with copper plates.

TITLE XII. Experiments concerning a new way of Esti∣mating the Expansive force of Congelation, and of highly compressing Air without En∣gines.

* 1.1HOW far we were able to compress the Air by the Incumbent weight of a Cylin∣der of Mercury, we have else where shewn; but to reduce it to a greater degree of Condensati∣on I made the following Experiments.

• 1. Having filled a Glass-Egg with Water till it wrought about an Inch into the Stem, we placed it in a Mixture of Snow and Salt, and in a few hours the Surface of the Liquor was raised about 7 Inches; and the Apex of the Stem being sealed up, by a fresh application of Snow and Salt it was raised 8 Inches higher: So that the Air being compressed into the space of an Inch, possessed about nine Parts of ten of what it did before: Whereupon the Stem being inverted and the seal'd end opened, the Air which when the Stem was inverted, rose up to the Ice, and separated the unfrozen Water in the Stem from it, powerfully expanding it self; forced out about ten Inches of Water, with Violence and Noise, besides a great number of Bubbles ascended from the Bottom of the Glass to the Top. N. B. when the Air was compres∣sed beyond seven Inches, we several times ob∣serv'd, That the Glass just above the Water on

• the inside was full of little drops of Dew, which when the Apex was broke off Disappeared.
• 2. A Vial whose neck was drawn out into a slender Pipe, being filled till it wrought an Inch within the Pipe; in a little time, by the Ex∣pansion of the Water, the Air being too much compressed, the head of the Pipe flew off; and the same happened to a round white Glass whose Stem, filled with Air, was about 3 Inches: Nor was the success otherwise when we re∣peated the Experiment in a large single Vial, whose Stem was four Inches long, and it's Basis an Inch broad.
• 3. An Oval Glass about the size of a Tur∣keys-egg, with a neck almost Cylindrical, was filled with Water within four Inches and a half, and then a piece of Paper being pasted upon the Stem divided into half Inches and quarters, and the Apex being sealed up by a moderate Heat; the Surface of the Water was raised considerably, but the Oval Part of the Glass being covered with a Mixture of Ice and Snow, the Air was compressed into a 17th Part of the space it possessed before; And the Ball of the Glass bursting afterwards with a considerable Noise, the Ice appeared full of Bubbles, which rendred it white and Opacous. In another Glass whose Ball was larger in proportion to the Stem, the Air was compressed into a 19th Part of it's former space before the Glass flew in pieces.
• 3. And this way of trying how far the Air might be compressed and Water expanded by Cold, we thought least Exceptionable; because the Pores of Glass are more impervious to Air

• and Water, than some Metalline Vessels; for having broken open the Apex of the Stem of one of our Glass-Eggs, we found, that tho' the Wa∣ter was but a little expanded; yet not finding a way out at the Pores of the Glass, the Water rose up a quarter of an Inch.

Notes

• * 1.1

  A new way of Estima∣ting the Ex∣pan•…•…e force of Con∣gelation.