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spoon, or other matter of light grasp be lifted to the mouth, as before described, it will not then be necessary to take it away from that position with the other hand as when the friction plate is used, for the reaction of the spring will continue the grasp, as the arm unbends by the downward movement of the stump.

Fig. 5.

One necessary aid to this instrument in all its forms is, to give support to its weight from the neck and shoulder; which, in the case of George Douseland is effected by a padded flat iron hook, surrounding a considerable portion of the neck, under the collar of the waistcoat, and passing behind it, so as to terminate on the shoulder, where it is cupped a little, to give it firmness of seat. To this part, the upper ring A of fig. 1 is attached by a couple of straps with buckles,-see fig. 5. By this means, the arm is not fatigued by the weight of the apparatus, and the joint F is at all times preserved in the same line of axis as that of the elbow joint, with which it has to move as on a centre common to both.

As the hollow ball and socket movement, previously suggested, will require very excellent workmanship to render it efficient, it will be as well here to remark, that with much coarser work the wrist movement may be effected by an external hoop, similar to H, fig. 1, containing a second, that can turn completely round freely within it, but 'confined from escaping by any of the usual means. The inside of this hoop should be cupped, so as to approach a section of the globu lar form; and a third hoop, externally, a similar segment of a globe, but a size smaller, must fit, without much nicety of adjustment, within the second. An axis passing through the centre of both these spherical portions is fixed to the inner one, but turns freely in a collar in the second the end being flush with its exterior surface. The ball and socket action, so far as it is used, is here derived from the one turning on au axis within the other, and not from the accurate fitting of these spherical portions. Any required position of the hand, which is attached to the inner ring, can be secured by a catch and holes to receive it, as before. On the centre of this axis, the tube D, fig. 4, may be fixed.

I am sorry to give you so many dry details, of no interest excepting to workmen, to whom, in fact, this communication is chiefly addressed, and without whose aid those who require the use of this instrument cannot procure it.

A much more simple and less costly hand than that worn by George Douseland, at the Polytechnic institution, might be made, chiefly of wood or bone, for poor persons; and I hope, that all good workmen,

who live by the use of their own hands, will, when called upon to make these humble substitutes for the poor man's capital, (for so, in fact, the hand is to him,) exercise a generous sympathy towards the sufferer. London Mechanics' Magazine.

Anastalic Printing.

Early in October of 1841, we received from a correspondent at Berlin, a reprint of four pages of the Athenæum, (which contained three wood-cut illustrations,) published in London only on the 25th of September. As we stated at the time," The copy was so perfect a fac-simile, that had it reached us under any other circumstances, we should never have suspected that it had not been issued from our own office and even with our attention thus specially directed to the subject, the only difference we could discover was, that the impression was lighter, and that there was less body in the ink; from which we infer that the process is essentially lithographic, the impression of the original page being, in the first instance, transferred by some means on to the surface of the stone or zinc plate. This, however, is but a conjecture, and our correspondent is unable to throw light on the subject. In reply to our urgent request for further information, he thus writes:

"Berlin, Nov. 25.

"I have not ceased to exert myself to obtain the information you desire, but all I can collect is briefly this:-The process by which these fac-simile reprints are produced, was discovered by a gentleman at Erfurt, and is kept a profound secret. I have since seen a copy of an Arabic MS. of the thirteenth century, and of a leaf of a book printed in 1483, both of which have been produced without the slightest injury to the originals, so that your Bibliomaniacs may despair of ever again seeing a unique copy. The parties in possession of the secret are about to re-publish here the Athenæum, and are to commence operations with the first number of the coming year. I have seen the draft of the Prospectus, in which they offer to supply the trade at the rate of three thalers (9s.) per annum. They will be content too, I understand, with 300 subscribers, and from this fact, you may form a conjecture as to the probable cost of the process, which must be below what the mere paper costs you."

The copy we received was submitted by Lord Monteagle to the commissioners appointed to inquire into the Exchequer Bill forgeries, in proof of the difficulty of guarding against fraud by any mere typographical arrangement. From that time, we heard no more of this wonderful discovery. We now learn, that the discoverer was M. Baldermus, now of Berlin, and that the process has been communicated to Mr. Woods, of Barge-yard Chambers, Bucklersbury. Whatever may be the results of such invention, our duty is to record the fact, and throw such light upon it as the state of our information permits. Thus we learn, that the original to be copied is prepared by

peculiar chemical means, and pressed in tight contact with metallic plates, whereby a reversed fac-simile is obtained; and after the metallic plates have been prepared by a second process, (which prevents the adherence of ink on the blank spaces) the impression is inked up with rollers, and printed from in the usual manner of surface-printing. Eventually, the proprietors are sanguine of being able to print from cylindrical surfaces, and consequently produce an unlimited number in a short time. Both sides of a newspaper can be transferred simultaneously on contiguous cylinders. Nothing can exceed the ease, elegance, and rapidity of the whole operation. The specimen workedoff for us, a page of L'Illustration, Journal Universel, was produced in less than a quarter of an hour from the first preparation. In fact, allowing seven or eight minutes for the absorption of a dilute acid, the thing is done as quickly as two sheets of paper can be successively placed on a plate of zinc, passed under the roller, and again withdrawn. Such an agent as this is, it is obvious, of tremendous power; if abused, it is fraught with the most fearful consequences; under proper and legislative regulation, it may become the greatest of blessings. But such an instrument most certainly must not be suffered to work out its own issues without guidance and without law, solely at the caprice and uncontrolled motive of self-interest. It is inconsistent with our present social condition, and must either modify or be modified by it.

London Athenæum.

This mode of copying engravings and letter-press, appears to have nothing whatever of novelty in it. A specimen of the same thing will be found in Senefelder's original work on Lithography, printed in Sienna, 1818. In this country it has long been known and practised. The members of the Franklin Institute will scarcely need to have recalled to their recollection the engraved stone, with the specimens of copied letter-press, which were deposited in our hall, for public inspection, in October, 1839, by Mr. Joseph Dixon, of Taunton, Massachusetts. A mode somewhat similar has been employed, under the name of Zincography, in London, many years since. And during the excitement caused by the French Revolution, in 1830, the French papers were copied and a new edition issued in Brussels in a few hours after their arrival, by an analogous process.

We insert with this notice, the specimen sent to us by Mr. Dixon. COм. PUB.

Nasmyth's Patent Steam Hammer.

Having, on several occasions, directed attention to Mr. Nasmyth's novel and ingenious invention, it must be interesting to our readers to be informed of its rapid and most successful progress towards general adoption, and which, we are glad to find, is giving the very highest satisfaction to all the parties who have availed themselves of so powerful and useful an assistant. One of the hammers was put in operation for the first time in Scotland, on Monday week, at the Dundyvan

The specimen of Transfer on the opposite page, - prepared for the Journal of the Franklin Institute, - was made in our ence this day, by M. Joseph Dison an Arabic work, printed

from

in 1767.

Taunton Ms. Oct 28th 1839.

Marcus Morton

-pres

Francis Baylies.

Henry Williams

James L. Hodges. Andi Bigelow

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