12 Dr. Fletcher on the Determination of the B. A. Unit 



Time. 



Galvanometer. 



Time. 



Galvanometer. 



m. s. 





m. s. 





5 50 



237 14 



28 5 



237 5 



7 



259 12 



29 15 



258 46 



10 20 



229 34 



32 45 



229 42 



11 30 



207 42 



34 



208 



15 40 



237 11 



39 



237 2 



17 5 



258 56 



41 



258 40 



22 



229 40 



44 15 



229 44 



23 25 



207 58 



45 25 



208 4 



Following is the general Table of results: — 



i 



Date. 



Nov. 24. 



Dec. 9. 



Dec. 14. 



Dec. 20. 



Dec. 22. 



Jan. 26. 



Feb. 16. 



Thermometer 



7320 



7320 



6165 



6165 



6165 



6165 



6165 



Temp, of water . . . 



24° -3 



25°-4 



27°-0 



26°-6 



26°-3 27°'2 



Temp, of B/ 



23° 



22°1 



23°-8 



21°-7 



23°-4 



4240 



4248 

 4229 

 4274 

 4216 

 4217 

 4204 

 4225 

 4225 

 4224 



4181 

 4164 

 4164 

 4184 



4180 



4222 

 4217 



4207 

 4195 

 4206 

 4204 



4182 



4198 

 4216 

 4232 

 4218 



19° 1 



4194 

 4192 

 4205 

 4193 



26° -2 



20° -6 



4207 

 4219 

 4174 



Means 



4230 



4173 



4206 



4199 



4216 



4196 



4200 



The greater number of results on Nov. 24 is due to the 

 fact that single thermometer-readings were taken instead of 

 groups. The two experiments with 7320 show the greatest 

 variation from the mean; but the mean of these two agrees 

 closely with the general mean. Experiments made on Nov. 

 29 and Dec. 6 were rejected on account of leakage of 3 and 

 6 grams respectively*. The results, however, are 4220 and 

 4227, falling within the limits of the series. The duration of 

 the experiment was less than one fifth of the interval between 

 the two weighings of the calorimeter; and probably the loss 

 during the experiment was the same fraction of the whole loss. 

 Furthermore, the leakage during the radiation-experiment 

 would affect the radiation-coefficient in such a manner as to 

 approximately compensate for the effect of leakage during 

 the main experiment. For these reasons I have retained the 

 experiments of Jan. 26 and Feb. 16, which showed a leakage 

 of 1 gram and 1*5 gram respectively, but have given the results 





