9

53 39 29,89 29,84,125 18 43

50

34 29,70 29,59,025

36 29,53 29,39 ,1

36 29,34 29,14,075

45 26 29,38

Stat. ,05

41 27 29,72 29,52,025

39 21 30,01 29,87

14

45

34 29,67 29,54

45 28 29,92 29,87

51

39 29,88 29,65,0125

47

41

29,44 29,28,025 33 29,15 29,02 ,35

19

23 46 35

24

29,41 29,22 ,3 43 32 29,49 29,42

50 25 29, 94 29,77,075 25 38 25 29,67 29,61

Edmonton.

CHARLES HENRY ADAMS.

Latitude 510 37 32 N.

Longitude 3 51 West of Greenwich,

To JOHN HOLMES, of Birmingham, in the county of Warwick, engineer, for his invention of certain improvements in the construction of boilers for steam-engines ; which improvements are particularly applicable to locomotive engines, and to steam navigation.-[Sealed 7th April, 1836.]

THESE improvements in the construction of boilers for steam-engines, are designed for the purpose of exposing a very extended surface of the boiler or steam generator to the action of the fire. The boiler is made of plate iron, and without small tubular flues, which are always liable to become choked with soot and dust, arising from the furnace, and which are extremely troublesome to clean.

The invention consists in constructing these improved steam boilers with hemispherical, or dome-shaped, or waggon-top-shaped compartments, one within another, the

VOL. IX.

2 c

plates or partitions forming alternately water vessels and flues. The heated vapour and smoke rising from the combustion of the fuel passes up between, along, and partly round the water vessels, the flues communicating one with another through such openings as will not impede the draft.

Plate IX., fig. 1, is a section taken transversely through one of the improved constructions of boiler; fig. 2, being a horizontal section of the same, both of which are taken through the furnace and water chambers. In this instance the fuel is fed in from a hopper, and deposited upon a revolving fire-grate; but these constitute no part of the present improvement, except in connexion with the boiler, as a convenient arrangement for locomotive engines and steam vessels.

The jacket or outer casing of the boiler a, a, a, a, forms the external flue leading to the chimney; b, is the furnace ; and c, c, the revolving fire-grate, mounted on a perpendicular shaft, which is made hollow for the passage of air, and operates as a blow-pipe to urge the fire.

The flues leading from the furnace are shown at e, e, e, passing up and down between, and embracing the water chambers, and ultimately conducting the smoke and vapours to the chimney f, which is furnished with a damper, to regulate the heat. The fuel is supplied from the hopper g, in small granulated pieces, gradually brought down by the rotation of a toothed roller h, into the shute i, from whence it falls upon the fire-grate c, within the furnace.

The fire-grate is made to travel round with its perpendicular support by means of a screw on the horizontal shaft k, taking into a worm wheel on the perpendicular shaft; and the toothed roller h, which feeds the fuel, is driven by similar means, the horizontal shaft being connected to the rotary part of the engine.

The steam generated in the water vessels by the heat of the furnace and flues, passes into the steam chamber 7, and thence through the pipe m, to the cylinder of the engine; a safety valve being placed at n.

This construction of boiler admits of being taken to pieces for the purpose of cleaning, by first removing the jacket, and then separating the parts by unscrewing them at the joints next the flues; the other parts of the water vessels are rivetted together.

The same construction of boiler may be furnished with a fixed grate; and the same principle of construction as regards the water vessels and flues may be made of a waggon-top-shape; of which latter form a vertical section taken transversely is shown at fig. 3, and a longitudinal section at fig. 4: and fig. 5, is a horizontal section or plan view of the same, taken on the level of the furnace.

In these latter figures, a, is the furnace; b, b, b, the water chambers; c, c, c, the flues leading from the furnace to the chimney, and in their course passing along and between the several water chambers longitudinally, instead of ascending and descending as in the former. The furnace is to be fed with fuel in the ordinary way through a fire door in the front: water is supplied to the boiler by a pipe d, the lower end of which is closed, and apertures are made in the sides of the pipe for the passage of the water. The steam chamber is at e, and the steam passes from thence to the engine through a pipeƒ; a safety valve iş applied at g.

Two longitudinal tubes h, h, extend along under the boiler, having small branch pipes leading into them from the water chambers: these are for the purpose of emptying the boiler when required, and of occasionally blowing off the sediment or deposit which may fall to the bottom of the water chambers.