16 C 2 Experiments on heat and cold; 



•mfeTrcd^Jhat ! han the thermometer indicated, but that the inequality ex- 

 the real change j** ec * on ty ^ or a few Seconds of time, becaufe the receiver, &c. 

 of temperature immediately impart heat to or abftraa it from fo fmall a quan- 



b V u^no" y v^r a ef- lity . ofairas 12 ° cubic inches > which are only equal to 40 

 feaive becauie grains in weight. The phenomena of the thermometer feemed 

 fo momentary. . ver y well to accord with the fuppofition of great heat or cold 

 ading upon it for a few feconds only. 



EXPERIMENT 2. 



E T*/ Vl rgt p urfuing this idea, I imagined that if two thermometers 



ana a imail ther- uri.ii. 



mometer were wh ote bulbs were very unequal in magnitude were inclofed 



fend ddiffC * to g ether > ^e Smaller bulb ought to give the greater variation : 



accordingly I inclofed two, the diameters of their bulbs being 



.35 and .65 of an inch refpe&ively ; and having exhaufted the 



air and reftored it again repeatedly in fucceffion, and found a 



mean of the variations, that of the fmall bulb was 2°. 8, and 



that of the large, 2°. 2. 



EXPERIMENT 3. 

 Exp. 3. And Repeated the exhauftion with the fmall thermometer in- 



was more cooled c ^ ^ e d in three different circumftances fuccefiively ; 1ft with 

 the more remote the bulb in the centre of the receiver ; 2d with the bulb reft- 

 ofTea^^ " in S on the wet leather of the plate; and 3d with the bulb 

 retting againft the fide of the receiver. 



1ft Cafe— Reduced by exhauftion - - 2°A5 



2d Cafe - - - 2 .15 



3d Cafe - - - . . - I .2 



1ft Cafe — Raifed by reftoring the air - 4 .05 



Id Cafe - - - - - 2 .25 



3d Cafe - • -2.8 



EXPERIMENT 4. 



Exp. 4. A cubic Inclofed a wine glafe with about a cubic inch of water in 

 was fenfibly xt » containing the bulb of a thermometer, in a receiver; and, 

 •ooled. exhaufting the air, the thermometer funk half a degree fud- 



denly, arid then continued ftationary : upon reftoring the air 



it fuddenly rofe half a degree. 

 From all which AH thefe experiments confirmed my conjecture of a much 

 the^Tchanee S reater degree of heat and cold being produced in thefe cafes 

 *as much than the thermometer points out, but that its continuance is 



