1851 Great Exhibition: Official Catalogue: Class X.: Gourlay, Mudie and Co
683A. MUDIE, DAVID (of the Firm of GOURLAY, MUDIE and Co), Dundee, Scotland — Proprietor and Manufacturer.
A salinometer. This instrument is represented in the following cut (next page).
The apparatus is placed outside the boiler, a pipe from which, A, communicates with the branch on the brine- receiver, B, which is cast in brass, with a solid closed bottom, but open at the top, to receive a slightly convex lid, which is bolted upon it. In this receiver is contained the hollow salinometer float, C, which is also of cast brass, with a solid top, the bottom being fitted in and made tight by a separate disc screwed on. In the centre of the top and bottom of the float, are light vertical rods, the ends of which carry the disc piston-valves, D, D, fitted to work accurately in the upper and lower cylinders, E, E, like pistons. The upper cylinder is cast in one piece with the cover of the brine-receiver, into which it opens, to receive the upper piston-valve of the float. The lower cylinder is screwed into the centre of the bottom of the receiver, on which there is a short collar formed to receive it. It projects for a short distance into the receiver, and forms a rest for the float, when the latter is in its lowest position, as shown in the cut. Both cylinders have a series of ports, F, disposed in a ring near the upper ends of each and it is by these ports that the brine escapes when the valves are open, passing along in the direction of the arrows, by the upper and lower copper branch pipes, G, U, to the main discharge pipe, H. A small spindle, I, passes up from the upper valve, to carry the adjusting weights, as well as to act as the salinometer index, by projecting into a glass index tube, L, carried upon the top of the small chest, which is screwed on to, and covers, the upper cylinder, M.