582 



Thermometry. 



No. 54 901 



54 901. 1 : 16. 



54 902. 1 : 12. 



54903. 1:12. 



54.901. Gas Thermometer after Chappuis, Figure (M. P. Ill, Fig. 79; Chwolson, Physik, s. d. 

 Vol. Ill, Figs. 6 and 7), model of the Bureau International des poids et mesuros, 



Paris, with platinum capillary i!8. 0. o 



This apparatus is especially adapted for very accurate measurements; only two readings are 

 necessary for the single temperature measurements so that the sources of error are not so great as in 

 instruments which necessitate four reading*. The tubes are wide enough to exclude any error of 

 capillarity. The readings are made by means of a cathetometer and with the aid of an accurate rule. 



54.902. Air Thermometer after Jolly, Figure (M. P. Ill, Fig. 73 [II, 2, Fig. 72]), con- 

 structed entirely of iron, steel stopcocks. The apparatus has a height of 1.6 m when 

 the rule is not extended. All bare parts are heavily nickelled. The thermometer Chamber 



is filled with dried air 12. 0. 



For filling, 5 kg mercury ( 2. 0. 0) is necessary. 



54.903. Air Thermometer after Jolly, Figure (M. P. Ill, Figs. 74 and 75 [II, 2, Fig. 73]), j 



with plate glass scale 5. 0. 



54,904. Air Thermometer after Jolly, Figure (W. u. E., phys. Prakt., Fig. 52). with plate 

 glass scale and micrometer adjustment for one limb 



r. I.'.HM;. Air Thermometer alter Berthelot-Alvergniat, Figure, on wood stand with fixed 



0. 10. 



scale 



2. 5.0 



r,.,,,r. Double-chamber Air Thermometer (Differential Air Thermometer), after I'laumller 



(M. P. Ill, Fig. 81 [II, 2, Fig. 80]). without stand 0. 



The two vessels eonlain air at different pressure, beiiij; exposed to I he same temperatures. 



54,908. -- idem, on stand, with scale. Figure 1. 



4.0 



As air thermometers use may be made of the apparatus for Boyle's (Marriot.te's) Law alter 

 Feilitzsch, Friedr. ('. <J. Midler. I'faundler. and Hulier. Xos. 52,812 et seq., also the apparatus 



after Lermantoff and Schneider. Xos. . r >2,706 52,70*. ci. 5376, 1725. 1726. 



