1888.J 



the Thermo-electric Properties of Bodies. 



233 



about ^ inch. The glass tubes in the previous method were imitated 

 in asbestos, and into the spaces S, S solder was melted, and thick 

 copper wires inserted, the other ends of which were kept cool by 

 water. When taking observations at high temperatures it is better 

 to cover this with a glass tube at the portion AA. Out of a large 

 series of readings we give four. 



Graphite Bods. — These rods were supplied by Hogarth and Hayes 

 of Keswick as pure natural Cumberland graphite. 



Length, 7J inches; diameter, 0*155 inch. 





Experiment 1. 





Time of observation. 



Temperature. 



R. in ohms. 



10 



21° 



42-3 



12.15 



600 



23-8 



12.25 



412 



29-7 



12.50 



278 



3372 



3.35 



21 



42-3 



Next day, 



11 A.M. 



12.50 

 2.55 

 4.30 

 5.54 



10.45 



Experiment 2. 



22° 

 155 

 202 

 278 

 390 



22 



30- 4 

 27-0 

 26-2 

 25*5 

 232 



31- 



Carbon Bods. — Carbon rods supplied by Woodhouse and Rawson, 

 Victoria Street, London. Very hard and good, 12 inches long; 



diameter, 0*22 inch. 



Time of observation 



3.15 p.m. 

 5 



6.40 

 7.35 

 8 



Next day 10 a.m. 



12.15 

 2.30 

 4.10 

 5 



Next day 11 a.m. 



Experiment 3. 

 Temperature. 



347° 

 309 

 298 

 257 

 226 

 23 



Experiment 4. 

 325 



273 

 221 

 202 

 22 



R. in ohms. 



4-75 

 4-75 

 4-81 

 4-85 



4- 88 



5- 2 



474 

 4-83 

 4-90 

 4*93 

 521 



