386

CHERRY'S PATENT INVALID'S BEDSTEAD.

a more

Science seldom appears in beautiful formn than when exerting herself in aid of suffering humanity. Dr. Arnott has soothed many an hour of agony with his hydrostatic bed; but there were objections to its use-such as its dampness, the impossibility of putting the patient in a merely inclined instead of horizontal position, from the tendency of the water to a level-which have prevented its use becoming so general as it otherwise would have done. Mr. Cherry's invention, if it does not afford that ease which results from the elasticity and fluidity of water, which bears equally upon every part of the side of the incumbent, and not upon any protuberances, such as the hip-joint, shoulder, &c. as must be the case where sacking or any kind of substantial bed is used, possesses many peculiar advan tages. Sir Henry Halford, Sir Astley Cooper, Sir Benjamin Brodie, Messrs. Guthrie, Stanley, and Keate, we understand, have seen and examined the bedstead, and have certified most favourably of its merits.

Description.

The engravings (fig. 1 and 2) in our front page are side-views of the bedstead. Fig. 3 is an end-view. Fig. 1, A is a key or winch, which fits on to the axle-heads of the different pulleys for working the bedstead; it is here seen at the end of one of the cylinders. B is the axle-head of a roller, round which webbing is rolled and fastened at the lower end of the quadrant E; by turning the webbing on to the roller, the quadrant, and with it the back-rest C is raised or lowered. D is an axle-head, with roller and webbing similar to B, to raise the knee-frame F; G an axle-head attached to roller, webbing, and quadrant, by turning which the whole bed-frame is raised to form a chair, as in fig. 2; H the position of the bed-pan.

Fig. 3, A and B, are cylinders or spring rollers, upon which the canvas C is stretched; the canvas is twice the width of the bedstead, one half being always rolled on one or other of the cylinders. The springs within the cylin ders may be set to any degree of elasticity.

The mode of operation will be more distinctly seen from the following directions for its use :

To prepare it for Use. -Wind up one of the cylinders until sufficient canvas

is on it to allow full play to the springs acted on by the incumbent's weight. or motion, and which in the bedstead is denoted by a mark on the sacking appearing on the top of the cylinder; then fix the cylinder by the bolt (seen at the sides of the cylinders A and B, fig. 3); afterwards wind the other cylinder until the sacking is drawn tight: the bed may now be made up on it in the usual way. The weight of the patient's body revolves the cylinders inwards, and he sinks enveloped in the bedding to a concave of from 3 to 12 inches deep, according to his weight, or the strength with which the springs are set up (see dotted lines C, fig. 3); he thus lies in a state of undulation, supported entirely by the springs in the cylinders.

To change the Position.-Apply the key (A, fig. 1) to either of the cylinders (A and B, fig. 3), and press it whilst you release the bolt, then let it gently revolve until the body rests on the platform under the sacking; then release the bolt of the other cylinder-by revolving the cylinder B you place the patient on his right side -by the other A, he is placed on his left -by revolving still further, he is on his chest. To raise his body, turn the axle B, fig. 1, to the right, till it is at the required elevation, and bolt it; the knees are raised by the axle D, fig. 1, turned to the left and bolted.

To form the Chair.-Raise the bedrest C, fig. 1, to an angle of 30 degrees (marked on the quadrant E, fig. 1), this forms the chair-back; then raise the knee-frame F, fig. 1, to 45 degrees, which forms the seat; lastly, elevate the bed. frame by the axle G, fig. 1, and the chair is formed.-See fig. 2.

To change the Bedding.-Place a table alongside the cylinder, npon which onehalf of the sacking is rolled, and make up the bedding on it, intersecting it as you proceed with the bedding in use, placing about 12 inches of the fresh bed and bottom sheet along the cylinder, and under the bed in use; you then revolve the cylinder on the opposite side, the bedding is drawn over it on to the floor, and is succeeded by the fresh supply; the patiently gently turns once over in the concave C, fig. 3, and the change is effected.

For Evacuations.-There are two apertures in the bed-sacking corresponding with one in the platform over the bedpan H, fig. 1; the bed or mattrass is also

perforated to correspond, (the aperture being usually closed by a cushion); the pan slides under the bedstead, and the patient is gently placed (by the cylinder) on his side, and the cushion removedthis effects a direct opening to the pan, and the patient is replaced on his back.

The advantages of the bedstead are stated to be the following:

1st. By it a patient may be elevated at the shoulders to any pitch desired. 2nd. The knees may be raised to assist in sustaining the weight of the body. 3rd. The whole frame of the bedstead may be raised so as to assume a perfect chairform, when the apparatus for raising the knees becomes the seat of the chair. 4th. The trouble and evils attendant on the introduction of a bed-pan are obviated. 5th. Bed-ridden and weakly patients are turned from side to side, as may be wished; or on the face when operations and dressings on the back are necessary. And, lastly, an entire change of bedding

is effected in one minute; and above all things be it observed, that every one of these operations of raising and lowering, turning and changing, are made without so much as touching the patient, and with an ease and a readiness calculated to soothe pain, instead of annoying or irritating the sufferer. The sacking of the bedstead being stretched upon spring rollers, imparts a most agreeable elasticity of action at every motion of the patient; while the operations of reading and writing, and the administering of food and medicine, are, by the various movements of which the bedstead is susceptible, greatly facilitated.

We understand that Mr. Cherry, the meritorious inventor, died soon after securing the patent. We hope that his widow and children will reap the benefit of his ingenuity. A model, we are informed, may be seen at the Adelaide Gallery; and the bedstead itself, by application to Mr. W. C. Lewis, 23, Leicester-square.

388

MACKINTOSH'S ELECTRICAL THEORY OF 41 THE UNIVERSE.

Sir,There is an old saying, that "there are none so blind as those who will not see." Kinclaven first infers from the passage he has quoted that the electrical theory is asserted to be in accordance with the laws of Kepler, and when reminded that no statement has been made with respect to its agreement or dis agreement with any law whatever, he betakes himself to the other alternative, and infers that it is not in accordance with those laws; and concludes his observations on that head by saying, "if the electrical theory is at variance with Kepler's laws, it is equally so with the Newtonian system." Perhaps Kinclaven will find in the end that it is not at variance with either the one or the other; that the electrical theory is an extension of the principle of universal gravitation; and that, with some qualifications, it is in perfect accordance with the laws of Kepler. The statements which have been made are general and indefinite, and, of course, under such circumstances those who are predisposed to cavil may draw inferences, so as to make the theory agree or disagree with any law whatever. If Kin

elaven will not understand, we must at least endeavour to put the matter in a. shape sufficiently plain that the general reader may not be misled by his misrepresentations. "From the most careful analysis of the phenomena of electric attraction, it has been deduced that the exact law of this force is the same as that of gravitation, namely, that its intensity is inversely as the square of the distance."

The mode in which the electricity imparted to a conducting body, or to a system of conductors, is distributed among its different parts is in exact conformity to the results of this law, as deduced by mathematical investigation." Now, if we find that the ordinary phenomena ascribed to gravitation may he referred with equal propriety to electrical attraction, then either hypothesis may be adopted indifferently. If we find particular instances in which the phenomena are better explained upon electrical principles, we are induced to give the preference to the electrical hypothesis in those instances, without perhaps rejecting gravitation altogether. But if we find, upon examining the phenomena more closely, some instances which cannot be explained

upon the principles of universal gravita tion, but which may upon electrical principles, then we are compelled to reject gravitation, and to adopt the electrical hypothesis, at least so far as respects those particular instances. In all cases if both forces follow the same law, the demonstrations cannot be affected by merely changing the terms. But if we adopt the electrical hypothesis, this includes the supposition that the earth is charged with electricity, and this brings us to another point in Kinclaven's letter.

It

He says, "I will ask Mr. M. is he certain of the existence of an electrical fluid." We are bound to suppose that Kinclaven is serious in asking this ques tion. Bishop Berkeley denied the existe ence of matter; in doing which his seriousness has not been questioned, al though some doubts have been enter tained with respect to his sanity. How ever, let us not misrepresent Kinclaven; he has not denied the existence of an electric fluid, although we might draw that inference with quite as much pro priety as has been done on his part with respect to the laws of Kepler agreeing or disagreeing with the electrical theory. Kinclaven having put the interrogative cautiously, brings forward Sir John Leslie with some "remarkable observations." This designation is quite appropriate. It must be allowed that the observations of Sir John are somewhat remarkable. is also remarkable and worthy of observation, that they happen to be published in a Number of the Mechanics' Magazine which contains their complete refutation by the able and, we may add, wouderful results (although they are not new) of the experiments of Messrs. Fox and Cross, as detailed at the Bristol meeting of the British Association. Well might Professor Sedgwick exclaim, that "the operations of electrical phenomena proved that the whole world, even darkness itself, was steeped in everlasting light, the first-born of Heaven." Whatever Kinclaven may think about the existence or non-existence of an electric fluid, he will not be hardy enough to deny that there are certain effects which have been ascribed to the action of an electric fluid, and which cannot be explained on any other hypothesis. Although Kinclaven is attacking the electrical theory with more asperity than to me appears needful, I hope he will never have the

1

existence of the fluid proved to him by the argumentum ad hominum from electricity itself. Kinclaven ought to know, that putting interrogations is a dangerous mode of discussing a question, because the respondent sometimes lays claim to the same prerogative. Can Kinclaven give a definition of gravitation per se, excluding the idea of matter?

Kinclaven says, "La Place has demonstrated that gravity darts its influence more than fifty million times faster than light; and sets for ever at rest the va rious speculative attempts to explain the cause of attraction by the agency of certain mechanical intermedia, and proves it to be a primordial and ultimate principle, ordained by the wisdom of the Supreme Architect." Now, Kinclaven must know, that all this is nothing, more or less, than sublime nonsense. By what intuition has La Piace arrived at a knowledge sufficient to enable him to determine primordial and ultimate principles? Does Kinclaven imagine that the progress of inquiry in that direction is to be for ever arrested by the interposition of vague and pompous assertions signifying nothing? It might be much more safely asserted, that men will never arrive at primordial and ultimate principles; that there is no resting-place for the human mind.

An objection has been taken to the Newtonian philosophy, to which Kinclaven has deemed it expedient to make no reply:That as the force of gravity acts against the momentum, the undiminishable must destroy the diminishable force within a given and not a very extended period of time. But we may take an objection on still higher grounds.

The Newtonian philosophy assumes that the motion of the planets is simply the continued effect of an original impulse imparted to them at the creation. Is this philosophy? Where is the demonstration? Where are the analogies? It is the philosophy of the trembling savage, who traces all physical effects to one unknown cause; the great connecting chain of cause and effect is almost wholly hid from his eyes. And because we have discovered a few of the inferior links (by far the larger portion being still obscured from our vision), it is confidently announced that we have arrived at a knowledge of primordial and ultimate principles. It is a natural tendency of the human mind thus to imagine. When

we have traced from the effects to the causes till we can trace them no further, we speculate for a time upon the probable cause, but finding the problem insoluble, we cut the Gordian knot, we break the chain of cause and effect, and at once connect the whole of these effects with one unknown cause presumptuously imagining that we have arrived at a knowledge of primordial and ultimate principles. All the operations of the Supreme Architect are consummated by the interposition and agency of secondary causes, by certain properties which he has been pleased to impress upon the elements of the material creation. It is the province of philosophy to trace and discover those properties and secondary causes, and by thus extending our know ledge of the things of nature, we are enabled to make them subservient to the well-being of man. Thus far may phi losophy go, and no further. Whenever we advert to Divine Power for a solution of natural phenomena, we virtually con fess that we have arrived at the limits of known causes the boundary which separates the known from the unknown. Therefore, the gratuitous assumption, that the motion of the planets is the continued effect of an original impulse, is a virtual confession of our ignorance of the cause of that motion.

"

It would be as well if Kinclaven would give satisfactory answers to these two objections before he proceeds to judgment upon the electrical theory; until he has done so, all his flourishes about rigid demonstration are mere bombast.

I perceive that the electrical theory has received an attack from an 66 Old Correspondent"-but as he has very candidly confessed that he is totally igno rant of the subject, of course he does not require to be answered. He should have informed himself, however, a little better before he ventured to give an opinion, "that it is all nonsense."

Your obedient servant,

T. S. MACKINTOSH.

P. S.-I intended to have made a few remarks upon "the precession of the equinoxes being one of the perturbations that tend to give an eternal stability to the system," but perhaps it may be as well to let them stand over for the present; let us settle the point in hand first. In the mean time, I would recommend Kinclaven to take into his consideration

890

MESSRS. UPTON AND ROBERTS' SAFETYLAMP.

Sir, While such a difference of opinion exists on so important a subject as the safety of the Davy-lamp, it would be well that those who have the opportu nity of proving it in practice, should communicate the result of their experiments to the public.

I am the more particularly induced to make this suggestion, from having remarked in Mr. Pereira's examination (vide Mechanics' Magazine, vol. xxiv. p. 338,) the following question and answer as referring to Messrs. Upton and Roberts' lamp "Have you made any experiments in coal mines with it? No, I have never been in a coal mine with it."

To this question, Mr. Editor, I am prepared to give a different answer, having since the publication of the evidence alluded to, had many opportunities of trying in practice the merits of the improved lamp, the safety of which I am enabled to confirm from repeated proofs of the unfailing property it possesses of destroying internal combustion before the wire becomes heated to a state of danger.

In my experiments with Messrs. Upton's lamp, I would beg to observe, that I have also usually had with me a

common

Davy lamp, by which I have proved the important fact that the latter is still safe after the improved lamp is extinguished, having proceeded several yards with the Davy lamp after the other was put out, the inflammable gas repeatedly exploding within the cylinder.

The advantages of Messrs. Upton's lamp in practice appear to be these: increased light, greater security of the gauze from external injury, steadiness of the flame while travelling rapidly, or in passing through currents of air, and lastly, the impossibility of internal combustion being continued so as to endanger the fusion of the wire. The disadvantages of this lamp (for these it undoubtedly possesses,) are its great weight 34lbs., and inconvenient height, 15 inches, both of which might, I think, be remedied in the construction without interfering with those principles which conduce to its safety. I think it will also be found that

in the critical examination of workings where a viewer has to determine the safety of introducing candles, the common Davy will be preferred, as the glass prevents that nice observation of the flame within the lamp, which guides the experienced miner in his vitally important decision.

These crude remarks will, I fear, ap pear unworthy of a place in your valuable Journal, and to obviate this in future, I would suggest that communications of this nature might be rendered more va luable were some of your scientific correspondents to propose such a list of questions as might appear most important to be answered from results obtained from inflammable gas as actually evolved in mines by the inscrutable operations of nature, and differing, as there is too much reason to suppose it does, from the most carefully manufactured approximations of our ablest chemists.

I am, Sir,

Your very humble servant, THE BLACK DIAMOND. Kilburne, near Derby, Aug. 31, 1836.

A SIMPLE METHOD FOR DRAWING ON BOTH SIDES OF A BOARD WITHOUT EITHER BEING RUBBED.

Sir, If the simplicity of any plan do not take away from its utility, perhaps the following contrivance (which occurred to me from reading one which bad the same object in view in your Magazine), may on that score be acceptable.

It is not at all unusual for draftsmen to be working at two different drawings at the same time; and in this case it would be very convenient to make one drawing-board answer in the place of being obliged to have two.

To effect this, I think that two slips of wood of the same thickness, provided with pins, say two at each end, and these made to fit in corresponding holes in the drawing-board at top and bottom, would be sufficient for the purpose. By these means a sheet of paper could be laid on both sides the board, and he used at the same time by reversing the pieces of wood from one side to the other, as occasion may require. The holes should be near the edge of the board to allow as much room as possible for the paper.

I cannot vouch for the originality of the above, as being so plain it may have