634 



APPENDICES. 



for a thermometer. In front the chest is closed in by a sheet 



of felt, a glass door, and a sliding 

 glass panel. The apparatus can be 

 suspended on the wall or supported 

 on legs, and is heated from below 

 by means of protected burners. 



The gas should pass first through 

 a pressure-regulator, and then 

 through a thermo-regulator to the 

 burners. 



Moitessier's Gas - pressure 

 Regulator. This apparatus is best 

 explained by reference to the dia- 

 gram (Fig. 269). In the bottom of 

 the cylinder (A) are the entrance (k) 

 and exit () gas-tubes. The tap (m) 

 regulates the size of the flame. The 

 cover (n n) roofs in the cylinder (A). 

 The bell (B) supports, by means of 

 e and /, the ball valve (cZ), which 

 lies in the cover (c c). The gas, 

 entering by k, passes through the 



valve (cZ), and is thence conducted by the tube a 'to the tube I. The 



bell (B) and the weighted dish (h) are screwed on to the connecting- 

 rod (g). To diminish as 



much as possible the 



friction of g in i, g 



only touches i by three 



projecting ridges. Section 



of i and g is shown at s. 



To put the apparatus in 



use it is first levelled, then 



h is screwed off, and the 



cover (n n) removed. A 



mixture of two parts of 



pure acid-free glycerine to 



one of distilled water is 



poured into the . cylinder 



until it flows out at q, 



which is then closed, and FlG< 209. -MOITESSIER'S GAS-PRESSURE. 



,, REGULATOR. 



the cover (n n) replaced. 



The manometers are filled with coloured water, and k and I 



FIG. 268. BABES' INCUBATOR. 



