472*
[ Unite ) 1
to matter on tlie moon, as on the earth, is less on thesurface of the moon than on the earth,—so that the col-lapse action had to operate on a very light material.
The causes of those vast ranges of mountains seen onthe moon’s surface has been suggested to be produced bythe continued progress of the collapse action of the solidcrust of the moon crushing down or following the con-tracting molten interior, which by the gradual dispersionof its heat, would retreat from contact with the interiorof the solid crust, and permit the crust to crush downand so force a portion of the original surface out of theway, and in consequence of this action, cause such toassume the form and arrangement of mountain ranges.In illustration of this important action, the familiar caseof the wrinkling of the surface of an apple, by reason ofthe contraction of the interior and the inability of thesurface to accommodate itself to the change otherwise,has been adduced.
The origin or cause of those bright lines which radiatefrom certain volcanic centres on the moon’s surface (Tycho,for instance) has been illustrated by the experiment ofcausing the surface of a globe of glass filled with water tocollapse on the fluid interior, by rapidly contracting thesurface while the water had no means of escape. The resultwas the splitting or cracking up of the surface of the globein a multitude of radiating cracks, which bear the mostremarkable similarity to those on the moon. This sub-ject is also illustrated by reference to the manner in whichthe surface of a frozen pond may be made to crack bypressure from underneath—so yielding radiating cracksfrom the centre of divergence where the chief dischargeof water will take place, while simultaneously all alongthe lines of radiating cracks the water will make itsappearance:—thus explaining how it is that the moltenmaterial, which had in like manner been under the surfaceof the moon during that period of its history, appears tohave come forth simultaneously through the cracks, andappeared on the surface as basaltic or igneous overflow,irrespective of surface inequalities.]
089 Oxley, W., Manchester — Manufacturer.Smith’s patent steam indicator and water indicator.
089a Dunn, T. Edinburgh —Inventor.
Electro-magnetic machine.
090 Gore, G., 31 New St., Birmingham —Inventor.Medical galvanic apparatus.
091 Hughes, .1., Queen St., Batcliffe —Manufacturer.Compass.
093 Perigal, H., jun. —Inventor.
Lunarian.
(596 Loot, —, Manufacturer.
A galvanometer, with the names Brett and Little,patentees, engraved on the dial.
097 Walker, John, 48 Princes Street, LeicesterSquare —Manufacturer.
Drawing-room clock, from a design by Mr. C. Grant;with subjects in panels embossed by Mr. G. Abbott. Thecase of the clock, which is electrotyped, consists of a baseand a pedestal of turquoise blue glass, surmounted byfigures indicating the progress made in the civilisation ofthis island. This is illustrated by seven subjects revolv-ing at the base: the savage life of ancient Britons—theRoman governor introducing agriculture—the encourage-ment given to Blemish weavers to settle in the island—
introduction of printing by Caxton—the improvement o
the steam-engine by James Watt —the opening,of * jfirst railway at Liverpool—and the movement which lcto the Great Exhibition . The clock shows the horn*and minutes on an open dial, supported by appropriatefigures. The signs of the zodiac are made to representhe months, and seven subjects, embossed in silver, fe c "similes of those in the pedestal, have been grouped soas to be seen at one view. The accompanying plate repr fi 'sents this clock.
698 Trotman, S., Notting Hill —Inventor.
Night clock. A lamp is suspended upon a lever, thelight from which is thrown upon each hour as it arrives.
700 Vulliamy, B. L., 68 Pall Mall — Inventor.
Model of a peculiar method of suspending the pendilum of a large turret clock. . n
Model of a method not generally known of suspendinga pendulum. Supposed to have been only twice reduceto practice; firstly, in the case of a clock the propel yof Her Majesty, and now at Osborne; secondly, m **great clock at the Post Office. The suspension of a P, _dulum upon the bases of four isosceles triangles is P'°_bably the best denomination for this method of susp c11sion. .
This model is made to a scale of six inches to a f°°^It was proposed in this clock to employ a two-secon^pendulum, which is preferable to any other for a la'nclock. In the model, the length of the pendulum is reg 1lated by the height of the stand from the floor. .
The principal pieces forming this suspension are ' 1 'following:—A base upon which the support rests; i° U jsupports connected together two and two; eight stcebearings; and the beam to which the pendulum >•attached.
As the following description must necessarily be vcbrief, an attempt is made, first, to describe the consti ution, and then to point out a few of its advantages. .
The apex of the triangles is the centre of motion; tfor the couvenionce of construction, is made continuousreference to the two triangles on the same side, °^. w l' 1 rSthe centres of motion are in practice very small eylinu®^answering the purpose of pivots, prolonged from theto the other. The reverse ends of the four supP 1 °. Jthough very short, are the bases of the triangles, whi jjwhen placed in their proper situation relative to eaother (which is done by means of the two c0,111 j 11 .weights), form the four supports upon which the P enlum rests. The pendulum is itself immediately, s ^ spended from a beam, the underside of which term) 11in a small cylinder, which in a similar manner, as '.ncase of the triangles, answers the purpose of two P*' 'The pivots of the triangles work in sinks instead of h° ^in four pieces of steel made perfectly hard, which P' ece u p.steel are kept in their places by the pressure of the s 1ports. The bearings upon which these four piecesare arcs of circles which, should any inaccuracies oCCU £ 0 Hthe execution of the work, secure for the pivots a gbearing upon the four pieces. The tops of the su PP v0 t s(upon which the four pieces of steel are, in which the P* .of the beam rest) are in like manner, and with the tintention, made arcs of circles; the four pieces tha _upon them are also loose pieces made of steel an P nlfectly hard. By this arrangement all inconvenience ^any inaccuracy in the construction is obviated, and a ^bearing given to the pivots of the beam. There ^arm attached to and projecting from the base of ea --ptsthe supports, terminated by a weight. These ^ e ^ ie \ract as counter-weights, to retain the supports mproper position. The weights move upon screws,!greater convenience of regulating their distance f i 0centre of motion. .,„ e %-
The action of the parts will now be very e , asl ] v0 tsplained. The pendulum being set in motion, the Pof the beam, and the bases of the triangles upon t |, ethey bear, roll together, the friction being removet