Improved Fire-Plug. 127 



Simplified Safety Diaphragm Regulator and Coal Economiser,' 

 has been in use in the engine-room of the Argus for the last 

 thirteen months, and has given great satisfaction. It consists 

 of a convoluted iron tube, opening into the boiler, in which 

 is a column of water, which, under pressure of steam, acts 

 upon a lever, and damps the furnace fire when the pressure 

 reaches the point beyond which it is not desired it should 

 rise. By moving a weight the apparatus can be made 

 to regulate the pressure to ten, twenty, thirty, or any other 

 number of pounds that may be required. It effects a con- 

 siderable economy of fuel, by obviating those frequent 

 blowings off" of steam, which occur through ignorant or 

 careless firing, and its use materially lessens the risk of 

 accident through neglect or inexperience in engine-driver or 

 stoker. The apparatus is inexpensive, and simple in its 

 construction, costing only a few shillings per horse-power of 

 boiler employed. It may be made by an ordinary black- 

 smith, and judging from our experience, costs very little to 

 keep in repair, that in use on our own premises having cost 

 nothing since it was fitted, more than a year since." 



One erected at Mr. Buckley's flour mills, Sandhurst, 

 proves equally effective. 



And one at the Melbourne Orphanage, Emerald Hill, has 

 been in use since 1867, and has, so far, maintained its 

 reputation as being effective, and costing nothing to keep 

 in repau". 



Art. XL. — Imiwoved Fire-Plug.^ By A. K. Smith, C.E. 



[Read IStli May, 1872.] 



It was found that in the City and suburbs, when the 

 pressure was off from the Yan Yean water mains, the gutta- 

 percha balls of the ordinary fire-plugs fell down, and that, 



• This invention consists of introducing a spring A, teneath the ordinary 

 gatta-psrcha, or other ball B, as shown in Jigs. 1 and 2, and which, by its 

 elasticity forces the ball against the india-rubber washer C, closing the 

 oriiice against the admission of sewage, or other matter, liquid or solid, into 

 the water mains when they are empty (from any reason), and thus iM'eventing 

 the contamination and waste of water when the mains are refilled. 



Claim. — The manufacture and use of a coiled or other spring of iron, 

 steel, brass or any other material, or elastic substance, or their mechanical, 

 equivalent, for securely closing the orifice of fire-plugs during the absence 

 of internal pressure in the water-mains. 



fir/. 3 shows the brass cup and spindle as indicated in Ji(js. 1 a^nd 2, 



