190 



TRANSACTIONS OF THE 



It is composed of two coils of the best wrought iron pipe of 1| 

 inch in diameter, to equal the area of an ordinary 2 inch feed 

 pipe; the inside coil about 9 inches in diameter, and an annular 

 space of 4 inches is left between it and the outside coil. The 

 coils are placed about half an inch apart to allow the products of 

 combustion to be drawn through them by the vacuum, caused by 

 the exhaust, the position of the coils being directly over the ex- 

 haust nozzles, which enables the heater to create a great and 

 equal draught through each tier of tubes. There are but two joints 

 exposed to the action of the heat ; it is easily removed if the 

 boiler should at any time want repairing. It heats the feed wa- 

 ter to or beyond the boiling point by the escape heat from the 

 boiler, and has a perfect circulation of water through it when 

 the pump is not in operation. It reduces the time taken to 

 get up steam one-third; which, together with the water being 

 put in the boiler at the boiling point, makes a saving of fuel. 

 It is not liable to get out of order, is simple in its construction, 

 and, from being self-acting, requires no attention from, nor 

 does it add to the duties of, the engineer or firemen. 



[.y3 silver medal awarded. 



Sees' Marine Heater. 



