574 



Heat. 



No. 54 830 



54835. 1 : 12. 



54 832. 1 : 5. 



54 836. 1 : 15. 



54.830. Apparatus after Weinhold, Figure, for projecting the phenomena of the freezing 

 of water and melting of ice, also the behaviour of water on boiling (VV. D. Figs. 331 333 

 [312 314]), consisting of two glass apparatus, one lead pipe cooling coil and one pro- 

 jection thermometer 



54.831. Glass Tube for showing the Circulation of Water, Figure (W. D., Fig. 341 [321]) 



* 54,832. - - idem, small, for use with the Projection Lantern, on heating stand, Figure 



54.833. Overflow Apparatus after Schaffer, for showing the motion of unequally heated water, 

 of glass, with stand (Bohn, Physikal. App. u. Versuche, No. 254; M. T. p. 145) . . 



54.834. Hot Water Heating, model of glass, on stand, after Schaffer (Bohn. Physikal. App. 

 u. Versuche, No. 255; M. T. p. 145) 



:> l .S3. r >. Apparatus for showing the Expansion of Mercury by means of the Alteration in Level 

 in communicating Tubes, Figure (W. D. Fig. 337 [318]), water-cooled; suitable for 

 explaining the measurement of expansion coefficient after Dulong-Petit-Reguault . . 



51,836. - - idem, after Dulong and Petit, Figure (M. P. Ill, Fig. 46 [II, 2, Fig. 44]; Gan.- 



Man., Fig. 477; Gan.-Rein., Fig. 328), with cathetometer 



The determination of the expansion of mercury is made by showing the change in height in 

 communicating tubes when one tube is cooled and the other heated. The mercury levels are read on 

 the cathetometer; the temperature is determined in the heating vessel by means of an air thermometer 

 having a long air vessel. Freezing temperature is maintained in the cooling vessel by melting ice. The 

 communicating tubes are constructed of steel tubing, the ends being formed of glass tubes inserted in 

 stuffing boxes. The heating vessel is of copper, being provided with a heating jacket. 12 Bunsen 

 burners projecting into this jacket heat the oil bath very uniformly to 280 C. in 8 10 minutes. The 

 cooling vessel is in three portions which can easily be screwed apart for cleaning. With the aid of a 

 gas regulator it is possible to maintain the temperature uniform for a long time. The overall height 

 of the apparatus is 1.6 m and breadth 1 m. 



* 54,837. Apparatus after Eiihlmann, Figure, for showing the Expansion of Gases at constant 



pressure, for the Projection Lantern (W. D., Fig. 342 [322]) 



s. d. 



0.14.0 



0. 4.0 

 0. 8.0 



0. 18.0 

 1.10.0 



0.18.0 

 15. 0.0 



0. 12. 



54,838. Apparatus for determining the Expansion Coefficient of Gases at constant pressure 



(diiy-Lussac's Law), after Weinhold, Figure (\V. I)., 4.. Edn., Fig. 343) .... 1. HI. u 



With this apparatus the value of (lie coefficient of expansion is obtained iivcurn'oly to the 'J ii 

 significant figure (4'h decimal). 



* Can be used with the Projection Apparatus. 



Cl. 6192. 1689, 



5888. 360. 1692. 



