AND SURGICAL INSTRUMENTS.
North, North Central, and South Central Galleries.
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° < 't Fox, R. W., Falmouth —Inventor.
Magnetic balance. The beam is supported by fineylmdrical axles, of polished steel, moving in holes ofsmall depth, made in agates, or hard metal • it is fur-l shed 'with an apparatus for diminishing the friction ofle axles in the holes, so that the ten-thousandth part of
a grain sensibly affects the balance ; the beam is magnet-ized, and it may, when required, be adjusted at O, bymeans of the index at the back, which is connected witha magnet within the box—the point of the pin beingrubbed during the operation. The following cut is afront view of this balance.
Fox’s Magnetic I’alance.
tills balance the body is weighed against the force^gnetism, instead of that of gravitation, as in the or-l nary balance. The beam is itself a magnet, and itssition is governed and adjusted by the repulsive actionsoother magnet.
le i* ac ^ us l the instrument for use, it must be carefully*ei' L the screws. The beam is then brought to the
0 Points by turning the deflectors. The weight andsi' i. eria ^ s to be weighed are then introduced, and the. door closed; the beam being released takes itsth ltl ° n ^th great accuracy, showing the difference ofI, 6 "taterials and weights by the small space passed overtill tlie P°'- n ' ts 0:f the needle ; or weights may he addedthe beam becomes perfectly horizontal.—E. H.]
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Yates, Emma Jane, 9 Portland Place,j Wandsworth Bond —Inventor.
h | 'o| l |T trU!nent tor the approximate determination of theern of squaring the circle.
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-t-'VER, Henry, Great Western Hallway, Ilungcrfordj, _ —Inventor.
Vo} v ;j’ lst ® r ed office-index and tablet memento. The re-ef ea ? Clr cular plate, being properly adjusted at the endand th ? ont h> shows the month, the day of the month,e day of the week, throughout that month.
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aollputt, W. B., Folkestone —Inventor.s ru ment for teaching the blind to write.
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^arxell, J., 3 King Edward Terrace , LiverpoolIWt Aoac?, Islington —Inventor.
^bbev-^ * e * 10use alarum, for the detection of fire am
tu <le in+i? a * sun '^ a ^ w Mcli may be adjusted to any lati-e northern or southern hemisphere .
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Inst ''ume
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Davidson, A„ Nairrw —Inventor.n ent for taking the girth of trees.
387 Wertheimer, D. J., 5 Charing Cross —Patenteeand Manufacturer.
Calculating machine, performing the operations of thefour arithmetical rules, viz., addition, subtraction, multi-plication, and division, simply by mechanical action; andapplicable for addition and subtraction of English money,from one farthing up to one million pounds sterling.
Calculating machines for Indian, American, Russian ,Prussian, Brazilian, Portuguese, Neapolitan , Roman,French, Turkish, and Chinese money.
Counting machine, for showing the number of strokesmade by a steam-engine, or any other piece of machinery ;and which can also be used for telling off scores, &c.
[Automaton calculation of this kind is effected by anumber of toothed wheels, each turning freely about itsown centre, and the “ value” of the operations dependupon the number of teeth in those wheels: thus, if awheel has 12 teeth, it may be used for "pence; anotherwith 20 teeth may be used for shillings, and so on. But,notwithstanding the skill and ingenuity bestowed uponsuch instruments, their power is very limited.—J. G.]
389 Darvell, Wm. John, Chesham , Bucks —Inventor.
An improved cooler, or refrigerator, for cooling maltliquors.
392 Boyle, —.
Reflecting telescope.
395 Matthias, John Henry, 47 Ilatton Garden, and1 Dorset St., BaUs Pond —Inventor and Maker.
New invention for dividing lines, upon a geometricalprinciple; made of German silver and of box.
396 Baker, Henry, 90 Hatton Garden —Inventor andManufacturer.
Steam gauge, upon the compressed air principle, show-ing the pressure per square inch, and also the temperatureof the steam at various pressures. (See fig. 1.)
Vacuum gauge, with sliding scale; the glass tube isprotected by a bronze covering. The same in a brass case,showing a scale of 22 inches and upwards, intended for
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