the supply of fresh water for conversion into steam, is very rapid and takes place with ease.
Messrs. Shand, Mason and Co.’s ‘Patent Inclined Water-tube Boiler’ is now applied by them to all Steam Fire-Engines of their construction, as well as for a variety of purposes where it is desirable to secure the greatest possible amount of power in the smallest space, combined with efficiency, economy of fuel, and durability of construction.
For Steam Fire-Engines, steam of 100 lbs. pressure can be raised in six minutes and thirty-five seconds from lighting the fire, while for general purposes an increase in the number of layers of tubes is made, to the extent of rendering the boiler most economical as regards fuel.
The boiler is constructed in two pieces, bolted together by an angle iron-faced joint, which affords immediate access to the whole of the interior; but on account of the rapid circulation of water in the tubes, this feature, although retained, is not found necessary in practice.
Bowling iron only is used, with the longitudinal seams welded, and all holes, whether for rivets or bolts, are drilled and not punched. The tubes are of homogeneous metal, and as the pressure is inside, and the ends are removed from the hottest part of the fire, no leakage whatever takes place, while the complete through passage in the tubes, combined with their inclined position, prevents the accumulation of deposit, which in practice invariably takes place in tubes where one of the ends is closed.
The Cylindrical Tube Plate and the tubes being exposed to equal amounts of heat, it follows that the diameter of the tube plate increases by expansion to exactly the same extent as the tubes lengthen, so that no displacement of the ends of the tubes can take place from alternate expansion and contraction.
The Fire Box is surrounded by a water space, which economises fuel, and avoids the necessity for a lining of