1147
2 Bosch, C. GS-errit, Amsterdam —Inventorand Manufacturer.
A case containing copper less oxidizable than ordinarycopper, applicable for shipping and other purposes.
83 Becker, C., Arnhem —Mechanician.
A balance, with weights. Its knife-edge rests on agateplanes. This balance will serve to determine weights upto seventy-seven grains nearly, and is said to turn withabout the jj^tli part of a grain.
Another balance, the knife-edges resting flat, andthe ends on agates; may be loaded with about 1,543 grains(upwards of three ounces troy) in each scale; and is saidto turn with about ^th part of a grain.
Another balance, resting on three points upon agateplanes, with 15,434 grains (upwards of 2§ lbs. troy) ineach scale, is said to turn with o^th of a grain.
A levelling apparatus, simple in use, and its adjust-ments are easily verified.
[Very sensitive balances are not only very useful in deli-cate experiments, but are also employed in very manypurposes of ordinary life. A high degree of sensibilityseems to have been given to the above balances, as theyascertain the true weight to a very small fraction of thewhole.—J. Gh] ______
84 Kaiser, A., The Hague —Manufacturer and Inventor.Tvdbewaarder (time-preserver), for the regulation of
clocks, a simplified astronomical clock with some newarrangements. It lias been examined by astronomers,by whose reports (published in the Konst en Letlerbodeof 1846, No. 18, and 1847, No. 14) the accuracy of thisclock stands comparison with a good chronometer,
85 TJiilman, Karel Wilhelm, Zkoolle —Inventor.
An equatorial sun-dial, of copper, with a moveable hour
and minute-hand, compass, label, and nocturlabe, 1 x 111011may be pointed to any place; with mechanism by whicha cannon may be discharged by means of a burning-glass.
86 Hohwu, Andrew, Amsterdam — Manufacturer.
An astronomical eight-day clock furnished with mer-curial pendulum. A two-day chronometer and otherarticles.
[All the substances of which a pendulum rod can bemade increase in length with an increase of temperature,and a compensated pendulum is one with a contrivancewhich will compensate the effect of the expansion of therod. The mercurial pendulum consists of a steel rod, towhich is attached a cylinder of glass or iron filled nearlywith mercury, the expansion of which on an increase oftemperature is just so much more than that of the rod,that the point of the centre of oscillation of the pendulumis as much varied by the expansion of the mercury upwards,as the expansion of the rod lets it down. The final adjust-ment of mercurial pendulums is performed by trial anderror, or by adding to or taking away mercury, as may berequired—J. Gk]
87 Logeman, Willem Martintts, Haarlem —
Manufacturer; Mr. Elias, Inventor .
A large permanent steel magnet capable of lifting aweight of 500 lbs. Another capable of supporting aweight of 100 lbs.; and a tliird, capable of lifting a weightof 30 lbs. The constant power of these magnets is saidto be more than double that which can be imparted tothe same mass of steel by the usual methods. The pecu-liar process of them construction is an invention of Mr.Elias, of Haarlem .
A common mariner’s compass, the compass needle ofwhich is acquired by the process above cited.
Electro-magnetic engine, applicable to the decompo-sition of water; also for blasting mines at the dis-tance of more than 300 feet, and adapted for the electric
telegraph. The improvement in the construction con-sists in the inductors rotating, not near, but betweenthe poles of the magnets. In this manner the magnetsact more energetically upon the inductors, and a cur-rent of greater power is developed by the same amount ofmagnctical intensity.
[The loadstone, or natural magnet, was for a long timeconsidered as the only body possessing the magneticproperties. It is an ore of iron, of a dark metallic greycolour. There are several different methods of makingartificial magnets, or causing hard steel to possess all thequalities of attraction and repulsion, &c., of the naturalmagnets.—J. Gr.]
88 Ifi)Eli, S. T., Rotterdam —Manufactm*er.
A clock.
89 Cazaux, J., Vallcenburg , near Leyden —Inventor
and Proprietor.
A dynamostater, to be used as a dynamometer forploughs, with a ehronometric mediator or controller ofthe indications of the instrument affixed to it. Ey a slightmodification this construction can be used as a dynamo-meter for measuring other varying strains. The machineconsists of two levers fixed to an iron frame, which act oneach other by a joint, under varying angles. To one ofthese levers is attached the plough-team, and on the otherthe counterpoise, which constitutes one of the factors forthe measurement of the power, which changes its positionas the strain augments, and is marked by ciphers on tl eiron section along which the lever moves. The cln*ono-metrical mediator of the indications of the machine con-sists of tw'o watches, provided with second hands, onewatch keeping its regular course, whilst the other, by allaccelerating apparatus of the balance of the clockwork,runs faster in proportion to the rising of the lever; thevelocity of the clockwork is so regulated that for everyaugmentation of the multiple of the counterpoise by one,the increase of velocity is two seconds per minute. Thenumber of seconds which the watch with the acceleratingapparatus runs per minute in the different positions of thelever, is marked in ciphers on the copper section alongwhich the lever moves. In drawing a burden which en-counters a variable resistance, such as a towed ship, or asledge in a rope-yard, owing to changes in the hygrometricconditions of the atmosphere or of the soil, the ordinaryspring dynamometers are not sufficient to procure the de-sired indications. Tlieir sensibility also, in many cases,is not sufficient to show the alterations of straining whichfollow in quick succession; these alterations being indicatedwith accuracy by the dynamometer. The instrument wasmade by a common village blacksmith, according to thedirections of the inventor. The axes w-ere applied, andthe clockwork executed by B. Van Beek, watchmaker, Ley-den. The accelerating apparatus of the clockwork is alsohis invention.
[A dynamometer is an instrument intended to measurethe muscular strength of man and animals, and a prettygood estimate may be formed of such by the use of theabove machine.—J. Gr.]
Mechanical tuning-key for pianofortes, with a supportfor the joining-piece of the tuning-key; particularlyadapted for an upright Brussels pianoforte. Theobject of this key is to insure greater accuracy when veryslight alterations of pitch are required. The supportbeing fixed in its proper place, tlic key is set on the peg,and the endless screw of the key is turned until thejoining-piece comes opposite one of the support chinks •into which the moving part of the joining-piece is lowered’.To suit differently formed pianofortes the support musthave a different construction. Made by B. Van Beekwatchmaker, Leyden.
[Ordinary tuning-keys are generally formed in onepiece of hard iron : in using thorn care must be taken to
4 X
[Official Tli.ustkated Catalogue.]