[Class X.
312
apertures left for its reception; one of them is situatedimmediately between the pectoral muscles on the chest:other apertures situated in the back, on the top of theshoulders, in the arms and legs, serve for the differentadjustments required; about the knee of the figure, themovements of which are regulated by an aperture in thethigh, the workmanship and mechanical ability displayedare very great. The thin external metal slips, whichoverlap one another very considerably when the figure isquite collapsed or contracted, are each furnished with along slit or cut-out groove, through which the pins fromthe plates beneath are seen to project; as these slips moveeasily over one another, it follows that when the figure isfully expanded, the slips can overlap one another scarcelyat all; and thus the power of variation in the dimensionsof the figure is dependent upon the individual length ofthese pieces of metal and their cut-out grooves.
The apparatus itself is not unlike in its general appear-ance to a fine suit of armour, displaying as it does thejust proportions of the human form, deficient only in theextremities. The entire machinery is totally concealed,and works noiselessly, and though the entire mechanismis of the most compound nature, the whole is easilymanaged and adjusted. In addition to the general adjust-ments which we have described, we may observe thatevery part of the figure has an independent adjustment bywhich it can be put out of proportion, and made to repre-sent the deformities or peculiarities of form of anyindividual.
We availed ourselves of an opportunity of carefullyexamining the interior of the mechanism of a similarfigure in the work-room of Count Duuin, it being impos-sible to obtain any correct idea of its internal constructionfrom an external view of the figure as exhibited. Thisexamination enabled us to form a high estimate of thegenius and mechanical knowledge Count Duuin has dis-played in its construction. The mechanical combinationsand parts employed are very numerous; they are asfollows: —875 framing pieces, 48 grooved steel plates, 163wheels, 202 slides, 476 metal washers, 4,828 spiral springs,704 sliding plates, 32 sliding tubes (to assist in the elong-ation of some parts), 497 nuts, 3,500 fixing and adjustingscrews, besides many other small pieces. The figure ismaintained in its vertical position hy means of a strongiron support at some distance from and affixed to itsback.
The invention, which is stated could easily be madeavailable in the artist’s studio, is designed to facilitate theexact fitting of garments, especially where great numbersare to be provided for, as in the equipment of an army, orproviding clothing for a distant colony, and will enablethe personal attendance of individuals to be dispensedwith, as from a new system of measurement the figuremay be adjusted to the exact form and size of the personto be fitted.
A Council Medal was awarded to Count Dunin for thisbeautiful piece of mechanism.
Lloyd (No. 322, pp. 444-446,) has exhibited a typho-deictor, or storm pointer, an instrument designed to deter-mine, by inspection, the bearing and relative position of arevolving storm, or hurricane.
The instrument is composed of a ring of metal, uponwhich the several points of the compass are engraved;attached to the centre of the circle, around which it easilyrevolves, is a larger pointer, with the words “ set this tothe wind” upon its face; in addition to the poiuter, twohands of a transparent horn are likewise made to moverouud the central point, one being designed for use in thenorthern, the other in the southern hemisphere ; but bothare intended to mark the ship’s place. Each arm is per-forated with a succession of small holes, for the adaptationof the instrument to charts of different scales. In thecentre is a revolving glass, which, resting on a moveablecentre and pivot, is made to revolve to the left when inthe northern hemisphere, and to the right in the southern;it is designed to illustrate the revolution of the windsaround their centre, and to determine the relative positionof a ship to the centre of a storm.
It having been ascertained by Colonel Reid that stormshave a progressive and revolving motion, and that on op-
posite sides of the equator they revolve in opposite direc-tions, the centre of the storm being nearly a calm, itfollows that the ship can be but in one position with regardto its centre, and that, in the event of the ship approach-ing the storm, or the storm approaching the ship, the edgeor outer boundary of it must be first encountered.
For the purpose of affording to seamen a practical illus-tration of the revolving winds, circles showing the gyra-tions of a storm, with directions for use upon them, havebeen made on paper which, for eonvemency, has beenrendered transparent; but these only prove useful in thecase of a circular storm, and would fail entirely in a pro-gressive whirlwind. Colonel Lloyd has the merit of sup-plying this want, and the Prize Medal was awarded tohim by the Jury.
Challis has exhibited an instrument for calculatingthe sum of the corrections of the three errors of a transitinstrument, adapted for the latitude of Cambridge, andfor any given N. P. D. The manner of determiningthese corrections is dependent upon certain geometricalconsiderations fully detailed in the “ Proceedings of thelloyal Astronomical Society f vol. x., No. 8. The instru-ment consists of a brass circular plate, moveable about avertical axis, passing through its centre; on the plate areengraved lines for the purpose of taking account of bothpositive and negative corrections. At a short distancefrom the circular plate is a contrivance for guiding themotion of two bars, which carry two fine parallel threadsof blackened unspun silk on the surface of the plate. Theinterval between the threads is made equal to the collima-tion error by means of a scale engraved on a brass plate,to which one of the bars is attached, and an index is fixedto the brass plate to which the other bar is attached; thetwo plates are clamped together by a screw; when thethreads are set to the required interval, the screw-headserves for a handle by which to move them. The circleis graduated, for showing North Polar distances bothabove and below the pole. The method for performingthe calculations and various details in the construction ofthe machine are fully described in the paper beforereferred to
With regard to the degree of accuracy of which themachine is susceptible, Professor Challis observes, that forcalculating the reduction to meridian transit, it has beenusual to form a table of the coefficients of the collinmtionlevel and azimuthal errors, arranged according to theNorth Polar distance, whence the coefficient for a pro-posed N. P. D. may be readily deduced; for the sake ofsaving time, the multiplication having been performed bya sliding scale. The usual method may be inaccurate toone hundredth, or even two hundredths of a second,whilst the machine by moderate cave will give the nearesthundredth of a second. The indications of the instru-ment, however, become more uncertain in proportion asthe North Polar distances are less, on account of the smallinclination of the threads to the correction scale; to meetthese cases an additional scale is engraved, near the con-trivance which gives direction to the threads.
Should the instrument be required for use in a latitudedifferent from that for which it was constructed, a slightaddition is required, but one which the instrument ismade to perform itself. Professor Challis observes, thatthe machine, which requires no little nicety of work, wasexecuted for him by Mr. Simms in a very satisfactorymanner.
A Prize Medal was awarded to Professor Challis.
Bluxt (No. 372, p. 450) exhibits a model of Eras-totlienes, as seen through a reflecting telescope of 9 incitesaperture, 7 feet focal length, and magnifying power 3S0.
The model is beautifully executed, representing veryaccurately this part of the moon. The large crater-likecup, with the neighbouring mountains and smaller eup-like valleys in their neighbourhood, are well shown. APrize Medal was awarded to Mr. Blunt.
Spratt (United States , No. 5, p. 1433) has exhibitedlightning rods. These rods, in their cross sections, aresimilar to the letter X, and are made either of copper orof iron. The points are formed of a compound of plati-num, silver, silex, antimony', bismuth, and tin, mixed incertain proportions. The extreme top being of solid