MORSE AND SARGENT. — RESISTANCE OF LEAD ACCUMULATOR. 611 



electrolyte is also the same in each case. The only difference is in 

 the distribution of the materials in the cell. 



Temperature Coefficient of Capacity. 



18. From the data of these measurements it is also possible to cal- 

 culate the temperature coefficient of the capacity of this type of plate. 

 The values so obtained are plotted in the curves of Figure 13. It will 

 be seen that they are nearly straight lines, and that they remain 

 straight for various end voltages. In practice such plates would hardly 

 ever be discharged below 1.6 volts at this rate, and the temperature 

 coefficient of capacity, for plates discharged to this point, is about 3.5 

 percent per degree. This coefficient is only applicable to plates of this 

 particular type, and to this discharge rate. For other plate types 

 and various rates the temperature coefficient of capacity has been found 

 to vary from 1.5 to 3.5 percent per degree. 



Literature. 



1. Hallwachs, Wied. Ann., 22, 95, 1884. 



Open circuit. Modified Kohlrausch bridge. 



2. Preece, Proc. Roy. Soc, 38, 352, 1885. 



Polarization not excluded. 



3. Haberlein, Wied. Ann., 31, 402, 1887. 



Open circuit only. 



4. Boccali, Elektrotech. Ztsch., 1891, p. 51. 



Modified Kohlrausch bridge. 



5. Uppenborn, Elektrotech. Ztsch., 1891, p. 157. 



6. Froelich, Elektrotech. Ztsch., 1891, p. 370. 



7. Streintz, Wied. Ann., 49, 564, 1893. 



Closed circuit, but polarization not eliminated. 



8. Wythe Smith, Physical Soc. London, June 24th, 1892. 



9. Nernst, Ztsch. f. Phys. Chem., 14, 623, 1894. 



10. Carhart, Phys. Rev., 2, 28, 1895. 



Measurements on Daniell cell. 



11. Grey, Elektrotech. Ztsch., Aug. 1, 1895. 



12. Nernst and Haagn, Ztsch. f. Elektrochem., 2, 493, 1896. 



Balanced both capacity and resistance. 



13. Haagn, Ztsch. f. Elektrochem., 3, 421, 1897. 



14. Haagn, Ztsch. f. Phys. Chem., 23, 97, 1897. 



15. Sieg and Schoop, Elektrotech. Ztsch., 1900, p. 226. 



