rack. If, on the contrary, any part is required to remain stationary, the handle is pushed in, and the pinion will thereby be thrown out of gear; and when the shaft n, is turned, the said pinion will revolve with its shaft, without having any effect upon the upright rack.-This part of the invention will be better understood by referring to figs. 10 and 11, which represent detached views of the rack and pinion motion;-fig. 10, representing a front view, with the pinion out of gear, and consequently the rack stationary ;fig. 11, being a plan view of the same.

In the sectional plan view, fig. 2, the pinion is represented as being in gear, and ready to raise the rack, whenever the shaft n, is put in motion;-the situation of the pinion, when out of gear, is indicated by the dotted lines.

From the foregoing description, it will be evident, that any one part of the jointed framing may be raised, while the other parts remain stationary, by putting in or out of gear, as may be required, the pinions which correspond to such parts. For instance,-in order to raise the upper part of the body of the patient, it will be necessary to observe the following directions, which will be better understood by referring to fig. 5, in the drawing.

The sliding tubes c, on the longitudinal or side jointed rods, are to be removed from the joints, as seen in the figure; but the sliding tubes, belonging to the top and bottom rods, are to be slidden over the joints of these rods, as seen in fig. 1; the handles, at the lower end of the bedstead, and marked *, in fig. 5, are to be pushed in, in the manner shewn in figs. 10 and 11, and in dotted lines in fig. 2, so as to throw the pinions, belonging to the racks, out of gear; but the handles, at the upper end or head of the bedstead, are to be pulled out, in order to put the pinions in gear with the racks. The hooks or catches q, q, (see

figs. 2 and 5,) are for the purpose of preventing the pinions from being thrown out of gear, by the handles being accidently pushed in.

Upon motion being communicated to the shaft n, by the winch handle, the right and left-handed screws, on the said shaft, will cause the large pinions or worm-wheels 1, 1, and the shafts k, k, with the four small pinions j,j, j,j, to revolve; and, as only two out of the four of these pinions are in gear with the racks, it follows, that those two racks only will be raised, the other two remaining stationary; and, as the jointed rods are left free to bend, they will assume the position shewn in the figure.

Again, if it be required to raise the patient entirely off from the palliasse, for the purpose of making the bed, all the joints of the rods must be covered with the sliding tubes c, c, as seen in fig. 1; and all the pinions must be thrown into gear, by pulling out the handles, as in fig. 2. Then, upon causing the under shaft n, to revolve, the pinions will gradually raise all the racks, until the jointed framing assumes the position shewn in fig. 7.

In the drawings I have shewn only four different positions, in which the patient may be placed; but there are many others which may be obtained, by raising one or two racks, and allowing the others to remain stationary; and also by removing the sliding tubes from certain joints, and covering other joints with the tubes, so as to make them rigid, and prevent them from bending.

As any person, from the foregoing description, will be able to arrange the apparatus in such a manner as to cause the body to assume any posture that may be required,—I do not consider it necessary to give any further description of the method of carrying the invention into effect.

In fig. 1, I have represented the supporting sheet, which is in fact a very thin mattrass, as attached to the rods d, d,

by means of ropes or cords, in the same manner as sacking is attached to an ordinary bedstead; but sometimes I fasten the supporting sheet or thin mattrass to the rods d, d, by means of straps, attached to the under part of the said mattrass. Fig. 12, is a section of the framing, shewing the thin mattrass attached, in the manner just described. A feather bed may or may not be used in conjunction with the thin mattrass, as may be required.

The patient may be raised to any altitude, from the bed and mattrass, that the toothed racks will admit of; and, if it should be considered necessary, the racks may have an extra length affixed to their ends, by joints, in the manner shewn in fig. 13.

In order to avoid confusion in the drawing, I have shewn my improvements, as applied to a common iron bedstead; but, with very slight alterations, they may be adapted to any description of bedstead, and in such a manner, that no part of the mechanism is apparent,—the bedstead, in fact, having the appearance of one of the ordinary construction. The apparatus or mechanism may also, at any time, be adapted to, or detached from, a bedstead of the ordinary construction, without the necessity and inconvenience of pulling the said bedstead all to pieces.

In figs. 13 and 14, I have shewn the method I employ for adapting my improvements to a four-post bedstead. Fig. 13, is a side view or elevation, and fig. 14, a plan view. a, is the post of the ordinary bedstead, and i, is the hollow tube, containing the toothed rack before described. The hollow tube is fastened by screws, or otherwise, to the wooden post, by iron braces r, r. The horizontal shafts k, k, (see former figures,) are mounted in bearings, fixed to the wooden side rails of the bedstead; and the longitudinal or endless screw-shaft n, is mounted in similar bearings, formed on the under side of the head and foot rails.

In fig. 13, it will be seen, that I have made the upper

or revolving joint of the toothed racks considerably longer than in the other figures; and I have also added an extra length to the lower end, which length is attached to the rack, by a joint; a portion of the lower end of the tube being cut away, in order to allow the extra joint to come out into the position shewn in the figure. The effect of this would be, that when the apparatus is wound up, in the manner shewn in fig. 5, the patient would be brought much more into a sitting posture.

In conclusion, I wish it to be understood, that I do not intend to confine myself to the precise arrangement of mechanism herein shewn, nor to the number of joints to be made in the jointed rods, as the same may be varied without departing from the nature of my improvements; but what I claim, as my invention, is constructing bedsteads, particularly applicable to invalids, in which the patient may be brought into any position that may be required, by means of racks and pinions, in conjunction with jointed rods, which may, when necessary, be stiff and rigid, and prevented from bending ;-any one, two, or more of such pinions, being thrown in or out of gear; and any one, two, or more of such jointed rods, being rendered stiff and rigid; or jointed, as may be required.-[Inrolled in the Rolls Chapel Office, June, 1840.]

We feel great pleasure in stating, that Mr. Thompson's Patent Invalid Bedstead, has met with the decided approval of some of our most eminent surgeons. The facility with which a patient, when reclining thereon, can be moved or brought in any position that may be required, is a desideratum of no inconsiderable moment to invalids.

We understand that a model of the bedstead has been submitted to Her Majesty, and approved of. We are also informed, that some of the London Hospitals have given

orders for one or two; and if they answer the expectations entertained by the medical gentlemen of these establishments, these bedsteads will, no doubt, come into extensive use; especially for accouchements, for which they are peculiarly applicable, as the bed can be made without at all disturbing the invalid. A complete bedstead may be seen at the Polytechnic Institution; and models and bedsteads, of various descriptions, are shewn and described by the Patentee, at his house, Maddox-street, Hanover-sq.-ED.

TO HENRY BERNARD CHAUSSENOT, of Leicester-square, in the county of Middlesex, civil engineer, for his invention of an improved construction of the lamps or apparatus used for burning gas, for producing a better combustion of the gas.-[Sealed 28th July, 1835.]

THE object of the patentee, is to heat the atmospheric air, which is to support the combustion of the gas, before, it comes in contact with the burner. For this purpose, instead of admitting the air, in its ordinary state, immediately from the open atmosphere, through the bottom of the gallery, as is the usual practice, the patentee encloses the ordinary glass chimney by an outer chimney or casing of glass. The air, for supplying the burner, is then admitted at the upper part of the outer tube, and passes down between the two glass tubes; which air, in its progress, becomes heated by the radiation of the flame, and enters the inner tube or glass chimney at bottom, in a heated state, near the burner. This mode of supplying the air, it is found, greatly assists combustion, and causes the gas to be more completely consumed, and to give out a more intense light than could be obtained if the combustion were supported by a current of cold air.