III. Assumes log e ^ = — '22408, and gives — (y — 2 m) = 4"683. 



ON THE CONDUCTION OF HEAT. 19 



Calculations. 



I. 1 2 3 4 5 6 

 62-9 35-92 20-52 11-72 6-7 3-83 



II. Gives e~^ = -589, A = 58*7, and 



1 2 3 4 5 6 



62-9 36-37 20-52 12-17 7-5 4-2 



III. Assumes e"^ = -589, and gives — (y — 2 »J) = 5-2705. 



1 2 3 4 5 6 



62-9 35-77 20-52 11-98 7 4-1 



IV. 1 2 3 4 5 6 

 62-9 38 20-52 12-28 7-4 4-7 



(6.) A bar of pewter. The temperature of the air = 17-34°. 

 No. of therm.... 12 3 4 



Exc.oftemp.... 63-41 35-17 21-52 15-52 



Calculations. 



I. 1 2 3 4 

 63-41 36-93 21-52 12-5 



II. Gives log e~^ = — -22408 and A = 58-83. 



12 3 4 



63-41 36-69 21-52 12-73 



3 

 12 3 4 



63-41 36-72 21-52 l2-7 



IV. 1 ^3 4 



63-41 36-14 21-52 13-18 



(7.) A bar of zinc. The temperature of the air = 5-62°. 



No. of therm.... 12 3 4 



Excoftemp.... 64-17 38-02 25-43 17*93 



Calculations. 



I. 1 2 3 4 

 64-17 40-4 25-43 16-01 



II. Gives log e~^ = - -19184, A = 59-64. 



12 3 4 



64-17 40-21 25-43 16*17 



III. Assumes log e~^ = — -19184, and gives — (y — 2 w) = 4*656. 



12 3 4 



64-17 40-2 25-43 16*18 



IV. 1 2 3 4 

 64-17 39-69 25-43 16-6 



(8.) A bar of lead. The temperature of the air = 17-12°. 



No. of therm. ... 1 2 3 4 



Excoftemp.... 65-13 29-42 14-93 9-99 



CalculaHo7is. 



I. 1 2 3 4 

 65-13 31-18 14-93 7*18 



II. Gives log e"*' = - -30776, A = 60-45. 



12 3 4 



65-13 30-89 14*93 7*38 



c2 



