ON ARTIFICIAL REFRIGERATION. 



947 



The Tipper opening is the outlet for ^as in the i)nTnp, and when use^ 

 on an engine the inlet for steam. The lar<;e central tlanjjed openinj,' is 

 hero shown provided with an induction valve as used in the jiump in 

 order to prevent the reflux of gas(!s towards the refrigerator. The lower 

 aperture comniuni(;ates with the water-jacket. 



At the right-hand Side of the drawing a bracket supports one end of a 

 small shaft used only in the engine as a means of moving the cut-oft" by 

 the action communicated to it by the spiral cam on the shaft below. 



Fig. 2. 



The second illustration shows one end, cover removed and exposing 

 to view an internal cover or piston-head, which is fixed by the screws 

 shown in the drawing to the piston within. This circular cover is seen 

 to work in a recess formed by a projecting ridge ; on the cylinder in the 

 outer circumference of this circular piston-head is a cast-iron ring to 

 pack and prevent leakage. Above the piston-head is a rectangular 

 plate which closes the si)ace occupied internally by the slide. The other 

 parts have been referred to above, but the form of the outer cover is 

 well shown on the right-hand side of this drawing. 



The third engraving shows the internal arrangement after removal of 

 the inner covers. The eccentric piston with the packing-bar at its 

 periphery and the slide i)ressing on it above. This slide winds up and 

 down according to the position of the eccentric piston. The slide is pro- 

 vided with two channel or ports communicating with two top openings, 

 one of which is uncovered and the •' mushroom" valve removed. This 

 cover and valve are drawn on the right-hand side as shown above. 



Sufficient has been said to point out very definitely the special advan- 

 tages of both engine and pump of this novel design. 



First. The combined engine and pump are very compact and perfectly 

 self-contained. 



Second. The position of the inlet and outlet ports at separate and dis- 



