LLUSTRATIONS. 
Page. 
Fig. 1. Apparatus for constant temperature between 0° and 100° „ 59 
2. Apparatus for constant temperature between 100° and 300° 60 
3. Boiling-point apparatus for mercury 61 
4. Boiling-point apparatus for zinc ; earlier form 63 
5. Boiling-point apparatus for zinc ; later form ; longitudinal section. .. 65 
6. Boiling-poiut apparatus for zinc; later form; cross-section 66 
7. Boiling-point tube for mercury ; original form 84 
8. Boiling-point tube for sulphur ; original form 85 
9. Boiling-point tube for water, etc. ; original form • 86 
10. Boiling-point tube ; perfected form 87 
10a. Boiling-point tube for annealing long wires 87 
11. Boiling-point tube for pressure work 88 
11a. Boiling-point tube for pressure work with accessories 88 
12. Ring burner 89 
13. Original form of boiling-point crucible . 91 
14. Perfected form of boiling-point crucible 92 
14a. Boiling-point crucible for pressure work 94 
15. Boiling-point crucible with open tube 94 
16. Machine for pressing porcelain insulators 96 
17. Die for porcelain tubes 96 
18. Disposition of thermo-electric apparatus ..-„. 97 
19. Double key 97 
20. Standard Daniell cell 100 
21. Chart showing the relation of temperature and electromotive force ; 
thermo-couples Nos. 17 and 18 114 
22. Chart showing the relation of temperature and electromotive force ; 
thermo-couples Nos. 22, 35, 36, 37, 38, 39, 40 116 
23. Apparatus for melting point of platinum 124 
24. Resistometer 132 
25. Detached rider 132 
26. Chart showing the relation between electrical resistance and tempera- 
ture coefficient of platinum alloys 150 
27. Chart showing the relation between electrical conductivity and tem- 
perature coefficient of platinum alloys 162 
28. Tubular displacement air thermometer 166 
29. (Withdrawn.) 
30. Diagram of Jolly air. thermometer and bulb 168 
31. Non-inglazed, spherical air-thermometer bulb 172 
32. Non-inglazed, re-entrant air-thermometer bulb 173 
33. Inglazed, spherical air- thermometer bulb 174 
34. Machine for soldering porcelain ; elevation , 175 
35. Machine for soldering porcelain ; plan 176 
35a. Gasometers 179 
(663) 9 
