496 



M. H. Weber on the HeaU conducting Poiver 



can, for control, calculate the constant P corresponding to each 

 s, which must come out equal for each of the values. 



All the following observations were calculated in this way. 

 The fundamental units of measurement employed are millimetre, 

 milligramme, and second; and accordingly the heat-unit is that 

 amount of heat which is capable of raising the temperature of 

 1 milligramme of water from 0° C. to 1° C. 



I. Iron rod {annealed). 

 Length . . /= 230-35 millims. D = 7-761 T = 5' 

 Diameter. . = 7-5168 millims. C = 0-1125 

 Distance of the mirror from the scale r=2927 millims. 

 = 2952-4 parts of the scale. 



The density and the specific heat were specially determined, 

 the latter according to the method proposed by Neumann. The 

 temperature-formula has been already given (equation 12). 







An ( 



3ven period. 







9. 



cr. 



3^2' 



S. 



s 

 calcu- 

 lated. 



Differ- 

 ence. 



P. 



45 



-440 



3-2 



-436-8 



-441-5 



+4-7 



729-8 



1 



-215 



0-4 



-214-6 



-213-9 



-0-7 



7244 



15 



- 32 



0-0 



- 320 



- ;^o-6 



-1-4 



7237 



30 



+ 117 



0-1 



+ 116-9 



+ 116-9 



0-0 



7-25-1 



45 



+235 



05 



+2345 



+235-5 



-1-0 



724 1 



2 



+331 



1-4 



+329-6 



+331-1 



-1-5 



7236 



15 



+410 



2-6 



0-407-4 



+408-0 



-0-6 



7245 



30 



+475 



4-1 



+4709 



-^469-8 



+ 1-1 



726-2 



45 



^52Q 



5-6 



+520-4 



+519-7 



+0-7 



725-8 



3 



-\-5Q7 



70 



+5600 



^5bQ-7 



+0-3 



725-4 



15 



+ 601 



8-3 



+592-7 



+592-0 



+0-7 



725-8 



30 



+Q27 



9-4 



+617-6 



+618-0 



-0-4 



724-7 



45 



+648 



10-4 



+ 637-6 



+638-9 



-1-3 



723 8 



4 



+667 



113 



+655-7 



+ 655-7 



00 



725-1 



15 



+ 681 



121 



+ 668-9 



+669-2 



-0-3 



724-8 



30 



+ 693 



12-7 



+680-3 



+ 680-1 



+0-2 



725-3 













Mean... 



7251 



Further, the height of the barometer, reduced to 0° C, was 

 758-97 millims. 



w,=99 96 C, 

 w.= 4-72 C. 



U = 5-37 C. 

 V^=33-14 C. 



K= 15-07 heat-units. H = 0-00267 heat-unit. In like man- 

 ner in the following periods we obtained the values : — 



