42 



HOT WATER APPARATUS. 



when first erected, in 1822, to answer every useful end, and upon this 

 ven; principle many are still erected. As this mode is only adapted to 

 situations where the boiler and reservoir is upon a level, the same in- 

 genious architect consti'ucted others with fixed covers, and also with a 

 perpendicular pipe, elevated to the highest level to which the water was 

 intended to he canied, and by these means he could cause the water to 

 circulate to any required height. This he has exemplified in a very 

 satisfactory manner at his mansion of Silvermeere, near Cobham, where 

 the boiler is placed in a cellar, and the principal rooms and passages 

 warmed by its means. 



It has been recommended, that in erecting this particular variety of 

 apparatus, the lower or returning pipe should be incHned so as to 

 allow a gradual fall of the water in its return to the boUer, This plan at 

 first sight appears very plausible, but the principle of its action is, in fact, 

 entirely erroneous, and appears to arise from considering the subject as a 

 purely simple case of hydraulics, instead of the compound result of 

 hydrodynamics. The experiments made by Hood led him to the con- 

 dusion that there must, under aU cu'cumstances, be a positive loss of 

 effect by inchning the pipe from the faither extremity' towards the boiler, 

 as we have elsewhere shev\Ti. 



Messrs. Kewley and Fowler appears to have each invented about the 

 same period what the former calls his siphon principle, and the latter his 

 thermosiphon, which is in principle almost the same tlmig, and by means 

 of which water can be earned in any direction. The former exhibited 

 his apparatus in the nurser}- of the late Mr. Colveile, m 1826, and the 



c 3 



latter took out a patent in 1829. Nothing can act better than Kewley's 

 siphon, and we believe that it is at present by far the most popular of all 

 other modes. A glance at the annexed diagram will explain its form and 



