THE LAWS OF CONDUCTION OF HEAT IN BARS. 



93 



TABLE VI. 



Case I. 



— 1^-inch Bar, Naked. 



Case II 



. — 1|-in.Bar, Covered. 



Case III. — 1-inch Bar, Naked. 





Formula ; 





Formula ; 



Formula ; 



log V = 



„,„,„. -008133* 

 = 2 ' 304 ' 1 1-0026*' 



log V- 



= 2 35215 



•01385* 

 1_-00007«' 



. O/IIOKK -0105K 



log, = 241255 ^mw 



t 



V 



observed. 



v calc. 



Diff. 



t 



V 



observed. 



v calc. 



Diff. 





observed. 



v calc. 



Diff. 



minutes. 







» 







minutes. 



o 







O 



minutes. 



o 











2-5 



1921 



192-45 



+ 0-35 



7-5 



177-0* 



1771 



+ 0-1 



9 



207-4 ; 207-5 



+ 0-1 



3 



190-3 



190-55 



+ 0-25 



8 



174-3 



174-3 



00 



10 



202-4 202-4 



0-0 



4 



187-15 



187'0 



-015 



9 



168-7 



1688 



+ 0-1 



11 



19745 197-4 



-0-05 



5 



183-5* 



183-45 



-005 



10 



163-6 



163-5 



-01 



12 



192-65 192-6 



-0-05 



6 



17995 



179-95 



00 



11 



158-25 



1584 



+ 0-15 



13 



1879 1879 



00 



7 



176-55 



176-55 



00 



12 



153-4 



153-4 



00 



14 



183-25 183-3 



+ 0-05 



8 



173-1 



173-15 



+ 0-05 



13 



148-4 



148-5 



+ 01 



15 



178-7 



178-7 



0-0 



9 



1697 



169-65 



-0-05 



14 



143-75 



144-0 



+ 0-25 



17-5 



167-5* 



167-8 



+ 0-3 



10 



166-55 



166-4 



-015 



15 



139-3 



1393 



0-0 



20 



157-55 



157-55 



00 



14 



153 45 



153-7 



+ 0-25 



16 



135-0 



135-0 



0-0 



21 



153-75 



153-5 



-0-25 



15 



150-45 



150-55 



+ 0-1 



17 



130-9 



130-8 



-01 



22 



149-9 



149-7 



-0-2 



16 



147-65 



1475 



-015 











23 



25 



146-1 

 138-9* 



146-0 

 138-7 



-01 



-0-2 



* Fro 



m interpolating curve. 





* Fron 



i curve. 



* From curve. 



consequently the progression is slower than geometrical, and the curve of the 

 " rate of cooling," in terms of v, is convex upwards, as already stated. 



89. Fifthly, By satisfying the observations by equations, we have farther these 

 advantages — (1.) We can, with approximate accuracy, extend the law of cooling 

 somewhat beyond the limits of observation, though with caution ; (2.) We can also 



obtain the values of -r in a ready and continuous manner. The higher parts of 



the curves in Plate V- have been deduced in this way, and thus the " rate of 

 cooling 1 ' has been tabulated for temperatures higher than those actually observed ; 

 but such numbers, being more or less hypothetical, are distinguished by asterisks 

 in the following Table, which in other respects includes the results obtained from 

 the observations treated as has been already described. 



VOL. xxiv. PART I. 



2c 



