MECHANICS AND USEFUL ARTS. 53 



EUGG'S STEAM BOILEIl WATER GAUGE. 



This invention, which is highly commended, is externally a glass tube, 

 two inches in diameter, and eighteen inches long, which may be placed in 

 any part of the building on the same story with the boiler, or on another. 

 A vertical iron pipe, half an inch in diameter, is inside of the glass tube, 

 placed by the side of the boiler ; this pipe is prolonged and enters the boiler 

 below and above the water line. In consequence of this arrangement the 

 water takes the same level in the pipe which it has in the boiler, but this pipe 

 being small, the water in it gets comparatively cool, so that any one may 

 easily leave his hand against the pipe below the water level, when the part 

 immediately above it is kept burning hot by the steam constantly condensing 

 inside. The glass tube is placed around the iron pipe, so that its middle cor- 

 responds with the proper level of the water; it is closed at both ends, and in 

 communication with a reservoir of water placed above it. When the com- 

 munication with the reservoir is opened, the water rushes into the glass tube 

 and rises around the iron pipe, but as soon as it reaches the hot portion of 

 the pipe it boils, and the steani thus formed, filling the glass tube, prevents 

 by its own pressure the water from rising higher. This steam condenses 

 slowly into water against the glass, Avhen the water, rising in proportion, 

 comes again in contact with the portion of the pipe which contains steam 

 inside, and furnishes a new supply of steam. The water in the glass is thus 

 kept on exactly the same level with the water in the pipe and that in the 

 boihr. The gauge in the upper story is on a different principle, and is acted 

 upon by the one below. The two gauges are made to communicate by a 

 pipe, and so much water is let in as will fill the pipe and one half of each 

 gauge. Of necessity, when the water gets down in the gauge below, it will 

 rise in the one above, and vice versa. The second gauge is graduated ac- 

 cordingly the reverse of the first. Several arrangements are now in use to 

 ascertain the height of the water in the boiler, but their principle of action 

 necessitates that they be on the same level with the boiler, and, in general, 

 cloie to it, where only the engineer can see them. 



FIRE-PLACE SHUTTERS. 



In many of the first-class houses recently erected in England, fire-place 

 shutters are provided, which, when partly drawn down, act as powerful 

 blowers ; and, when wholly drawn down, so as to touch the hearthstone, 

 entirely close up the fire-place, and instantly extinguish the combustion of 

 the fuel in the grate, or that of the soot in the chimney, should it accidentally 

 take fire. 



OX ARRANGEMENTS FOR THE CONSUMPTION OF SMOKE. 



The London Engineer publishes the following proposed new theory of 

 smoke-consumption. This inventor proposes to purify the smoke by water 

 in its passage from the furnaces to the chimney ; in other words, to wash out 

 a large portion of the obnoxious elements of the smoke. His theory is 



5* 



