KEWLEY AND FOWLER'S SIPHON. 



43 



principle. From nearly the top of the boiler, c, (which is without a cover) 

 the upper leg of the siphon, ^, rises and proceeds to the extremit}- of the 

 space to be heated ; through this upper pipe the hot water flows and 

 returns by the lower leg and enters the boiler at the top, but is continued 

 downwards to near the bottom of it. At the extremity of the pipe, as at 

 c, a small hole is made in the tube, to which an air pump is apphed to 

 empty it of air, and as this process goes on, the water flows into them 

 and occupies the space. Next to Atkinson's original plan, this is the 

 simplest in operation, but requires greater nicety in the erection, and 

 those intending to adopt it cannot do better than employ the inyentor, 

 who, besides being an honest and unassuming man, is a most ingenious 

 and clever engineer. 



The thermosiphon will be readily understood by a reference to the 

 annexed diagram, and is thus described in the Gardener's Magazine, 

 vol. X., p. 453, after explaining the principle, which 

 is by employing the power of the fluid in descending 

 one leg of the siphon to draw up hot fluids in the 

 other ; by this means, hot fluids will circulate from 

 one boiler to another, or from one vessel to another, 

 through pipes of various forms and lengths, Sup- 

 posing the water of a uniform temperature in both 

 legs of the siphon, a no circulation would take 

 place ; but supposing it to cool sooner in the long 

 leg a, than in the short leg 5, then the equihbrium 

 would be destroyed, and the water in the long leg a, 

 would descend and draw up hot water through the 

 short leg b, and this circulation would continue as 

 long as the water at c was maintained at a tem- 

 perature above that of the surrounding atmosphere. 

 We consider this method better adapted to the pur- 

 pose of raising water to heat baths and dwelhng houses than that of 

 hot houses, although, no doubt, it can be apphed to the latter purpose 

 also. 



The next in order, we may place that of Mr. Week's, which is intended to 

 cause the water to circulate below *the level of the boiler if required ; but 

 for this purpose it is necessary to raise the water to a height above the level 

 of the boiler equal to the distance which it is intended to sink it below that 

 point. This may be done in any closed boiler, with a tube proceeding from its 

 cover, or in any boiler of a height above the fire, equal to the depth below 



