THE London JOURNAL AND REPERTORY OF Arts, Sciences, and Manufactures. CONJOINED SERIES. No. L. Recent Patents. To JOHN MALAM, of Kingston-on-Hull, in the county of York, civil-engineer, for his invention of certain improvements in gas-meters, and in the apparatus for generating gas for illumination.-[Sealed 2d June, 1835.] THESE improvements in gas-meters, and in the apparatus for generating gas for illumination, consist, in the first instance, in a new and simple arrangement of the parts constituting the meter, and in the mode of suspending it, whereby the friction or resistance of the water employed in the common meters is considerably overcome, and the working parts of the machine are much less exposed to injury from the chemical action of the impregnated water, there being but a small portion of the cylinder by which the gas is measured im VOL. VIII. T mersed in the water. It will be perceived, that as the friction is diminished by my improved arrangement, the rotary velocity of the meter is increased; consequently, a much smaller machine will be required for the passage of a given quantity of gas than those of the ordinary construction. Secondly, the improvements in the apparatus for generating gas for illumination, consist in an addition to the retort commonly in use for the purpose of effecting a more perfect decomposition of the vapour arising from the coal in the process of distillation, and rendering that part which would otherwise be condensible into tar and ammonia into a permanent elastic gas, thereby greatly increasing its quantity, and rendering the gas of a more pure and better quality. Retorts of the ordinary construction with my improvements may be worked at a much lower temperature than usual, as that portion of the vapour which passes off from the first process of distillation is perfected by the second, and thus the durability of the retort is considerably increased; which advantages are obtained from the ordinary quantity of coal, and at no additional labour or expense in the mode of heating or working. For the better illustration of my improvements, I have attached two sheets of drawings, marked with several figures and letters of reference, for the purpose of pointing out the several parts more particularly. Plate V. exhibits several views of the improved meters adapted to two different varieties of situation; the one being a small meter made on the plan which I should recommend for registering the consumption of a small number of lights, and the other showing the construction which I prefer to employ where the passage of a large quantity of gas is required to be measured, and also my proposed additions to the retorts now commonly in use, which I call a "generator." In this apparatus the gaseous vapour is submitted to a second process of distillation, and thereby improved in its quality as well as increased in quantity. Fig. 1, represents an elevation of my improved meter, on the construction I propose to be employed to register the consumption of gas for a small number of lights up to eight or ten; fig. 2, being a sectional elevation taken through the middle of the machine; fig. 3, is a plan or horizontal view, as seen from above, the top or cover being removed, the better to show the interior; and fig. 4, represents another plan of the same, the drum or cylinder of the meter being shown in a vertical position, that the passages for the gas may be more distinctly seen. There Fig. 1, a, a, a, represents the outer casing of the meter; b, the pipe for the ingress of the gas, connected with the chamber and upright central pipe c, c. is a tube d, d, surrounding the upright pipe c, which is supported by the annular float e, e, e ; and the pipe d, d, is so constructed that it will support the footstep or bearing of the axis of the meter, which is seen within the upright pipe c. It will be seen that the shaft or axis of the machine is supported at the top by the arms or frame g, g, in connexion also with the annular float e, e: hence it will be evident that as the float is always horizontal, the angle of the inclination of the axis of the meter will be invariable. The drum or cylinder of the meter is shown at h, h, h, and is mounted at the proper angle of inclination, which is shown in the drawing at about one-fourth of its diameter, and of course may be varied at pleasure. It will be seen in the sectional elevation, fig. 2, that the height of the water which is represented at i, i, must meet the lowest point of the inner circumference of the top of the cylinder h, h; and the lowest point of the bottom edge opposite will dip into the water sufficiently to seal the gas and prevent its escape, except through the proper passages, from one division of the cylinder to the other. The different compartments of the cylinder, with their passages, will be more clearly seen by reference to figs. 2, 4, and 5. The gas proceeding through the fixed pipe c, into the central chamber k, of the cylinder, from whence it passes in radial directions to the circumference, through.... the four passages 1, 1, 1, 1, on the top of the cylinder, into the segmental passages m, m, m, m, next the outer circumference of the cylinder, which are so divided that the gas passes into the four inner compartments n, n, n, n, (see fig. 5,) which is shown inverted, ascending on the one side, and is discharged as it descends on the oppo. site side. The passages for the ingress and egress of the gas, and the four compartments through which it passes to be measured, are marked with corresponding figures; that is to say, that as the gas proceeds from the central chamber k, through /1, on the top of the cylinder, it thence passes through the circular divided passage m1, to the compartment n1, in the cylinder, and so on, and is discharged at the opposite point to which it is received, and which is further shown by the direction of the arrows. In case the water should decrease by evaporation, or otherwise, it will be seen the float and meter will descend with the surface of the water until its progress is arrested by the valve o, suspended from the footstep of the shaft f, in the pipe c, falling upon its seat p, which will entirely exclude the admission of the gas until a further supply of water is given. At the |