The mechanics' magazine, museum, register, journal, and gazette. No. 1128, Saturday, March 22, 1845 / edited by J.C. Robertson.

Date:
[1845]
Catalogue details

Licence: Public Domain Mark

Credit: The mechanics' magazine, museum, register, journal, and gazette. No. 1128, Saturday, March 22, 1845 / edited by J.C. Robertson. Source: Wellcome Collection.

    10/20 (page 200)
    can be effected by catgut or other ten¬ dons attached to the joints of the fingers, as in the natural hand, and terminating in loops or eyes, on different parts of such a hinged bar as F H, fig. 4, so as to give them different ranges of tension to suit their respective purposes. This structure implies the necessity of a coun¬ teracting worm, or other spring move¬ ment, to extend the fingers and thumb again. Very light and elegant hands may be made on this plan, which would be suitable for the fair sex, and for light work. I before said, the first drawing made of the hand for George Douseland was on this plan; but I found that he could lift the weight of five stone with the stump, and that the strength, pre¬ cision, and durability of steel joints and tendons was more suitable to his work. These have also the great advantage of giving both extension and contraction, with no counteracting spring to weaken the effect. By one simple, lasting, and efficient means, both these actions are effected with perfect precision in all weathers. This instrument, in all its forms, has only been represented as working when the spring bolt L, fig. 1, secured the lower arm from turning on the hinge F ; but conceive this spring bolt occasionally drawn back, and secured from acting; . and that a spring friction plate held the joint F, from turning, with less than three stone weight applied at the ring D by the stump, the grasp of the hand could then be used only up to that extent of pressure, sufficient, say, for example, to lift a can full of liquid; thus, if more than three stone force be applied, the friction of the joint will be overcome, the can will still be retained with the same power, but the movement of the joint will allow it to be lifted to the mouth. This is only one example of a very important principle, applicable to innumerable instances, and which greatly increases the use of the apparatus. , (To be continued.) LIGHTING BY ELECTRICITY. Mr. Weekes’s plan for lighting towns by electricity, which first appeared in the Me¬ chanics’ Magazine, as far back as June, 1831, and has been since fully developed by him in an article in the Electrical Maga¬ zine for January last, republished in this Journal of the 12th January, has been lately reinvented in America, by two persons in Cincinnati, of the names of Mills and Saun¬ ders. We extract the following notice of a successful experiment made by them from the Cincinnati Mechanic :— “ The apparatus with which the light is made is small, to allow of easy transporta¬ tion. But it may be increased to an inde¬ finite extent, and with its enlargement is the increase of the size of the light. From our own observation we should suppose the power of the light could not be increased. We never could conceive a light more bril¬ liant. Though but the size of a pea, it is sufficient to illuminate quite a large room, and forbids the steady glance of the eye. The blaze of a candle 20 feet distant from the apparatus, and 3 feet from the wall, cast upon the wall a thick shadow—so much more brilliant is ‘ the light/ though not one-twentieth the size of the candle’s flame. What will be the power of this light when increased to the size of a gaslight? We cannot conceive. The apparatus is not costly; and for lighting Cincinnati, two towers will be considered sufficient to illu¬ minate the whole city, and at a very small expense.” fenn’s SPRING ADJUSTING PLANE. [Registered under the Act for Protection of Articles of Utility. Joseph Fenn, of Newgate-street, tool- maker, Proprietor.] We have here another valuable addi¬ tion to the list of mechanical tools, from the eminent workshop of Fenn, of Newgate-street. Fig. 1, of the prefixed engravings, is a side elevation of this improved plane, partly in section. A is a bed plate for the cutting iron D; Ba screwed rod fixed at the back of this bed plate, being passed through bearings a a, projecting from the bed plate at top and bottom. 'C is a traversing nut which works on the shank of the rod B, and has an oblong pin b, which protrudes from it into and through a groove which runs down the centre of the bed plate. The cutting iron D is attached to the bed plate by means of the pin b, which fits into a corresponding hole in the top of the iron; and as this pin is raised or low¬ ered, by the turning of the screwed rod to the right or left, it raises or lowers the iron. E is the cover of the cutting iron ; F is a spring holder, a plan of which is given separately in fig. 2; / is the handle of this holder, and g the spring at the back; hx is the