

WINIX 



\VINHMII.I.. 



no 



rapidity : "M I'urckhardt observes tliat in Africa :;!: I tlic I'.vt the 

 es the face of t!. :ii; to the atmosphere a blue, a 



, IT a rvddish tint. ( III -.T, An . 

 occasionally observed columns of rond in motion in tln-iir 



ica. 



The fatal effect* which have been mid to result both from the 

 liuum .-:ir,d .iint iVum the supposed d. : ';alityof 



the winds, arc now considered as exaggeration!: uicncvs 



nil I v jnt-n and animals during the continuance of the hurricane are 

 rhirtly such .-,s arise from the lte.it and dryncss of the air, and from 

 the qu.-mti- which is blown into tho eyes. [S 



SIR.) 



Some short notices on the theory of cyclones, and probably allied 



uiena, must conclude this article. In Sir J. Hcrfch< Ts ' 

 on the liednction of Meteorological Observations,' presented to the 

 thirteenth meeting of the British Association. I-! 1 ., i.- 

 t!.. philosophy of what he calls winds of barometrical osc'u' 

 arising from local, and temporary causes prevailing over great areas 

 simultaneously, and occasioning, eventually, an extensive atmospheric 

 undulation, he applies the subject to the theory of cyclones in the 

 following manner :" Some of the principal of the phenomena of 

 revolving storms would seem capable of explanation in this way of 



Aing winds of oscillation, and in which they would become 

 traced up, not to funnel-shaped revolving depressions in the nature 

 of waterspouts, but simply to the crossing of two large long [atmo- 

 spheric I >aroiih trical] waves running in different directions. The 

 way in which a rotary movement in an ellipse or circle, or in 

 in some other partly oval and jiartly rectilinear figure, ma}' result 

 from the combination of two rectilinear movements of advance and 

 recess, will easily be understood by the analogy of the circular and 

 elliptic polarisation of light, where rectilinear movements of the 

 ethereal molecules are conceived to be similarly combined. [ELLIPTIC 

 ISATIOX.] Some features in auch storms are strongly in har- 

 mony with this view, namely, the fact that in them the direction of 

 the wind at a given locality never makes more than one rotati 

 not always that ; and that in the central line of the storm's progress 

 * .1 simple ami sudden reversal of direction. On the other hand, 

 it must not be concealed that some features militate against it ; for 

 instance, the fact that such gales are stated always ' to revolve ' in one 

 direction, where**, on this view of their origin, the changes of wind 

 ought to be in opposite directions on opposite sides of the medial 

 line." 



M . I.artigue, in a japer on the storms of the Pyrenees, communicated 

 ich Academy of Sciences on the 3rd of December, 1855, 

 and of which an abstract appears in the ' Comptes Itendus,' has some 

 remarks on then* analogy to the hurricanes of the intertropical regions, 

 and of the seas adjacent to the coasts of the United States of America. 

 In these he announces an explanation of cyclones substantially identi- 

 cal with that of Sir J. Herschel here given. Two illustra 

 represent a storm determined by winds the direction of which are per- 

 jwndicular to each other, and another prodin -il by winds having 

 diametrically opposite directions.. 



The following impoitar.t su;g;tion on the immediate cause of hur- 

 ricanes, has been made by Sir .). Herschel in several of his work 

 anteriorly and subsequently to the preceding : it is now extracted from 

 .oiiouiy," 1849, par. ('24;")), n.tr: "It seems worth 

 inquiry, whether hurricanes in ti> not arise from 



-.ii'f the upper currents [e; tutorial air] prematurely 



diverted downwards before their relative veloci' u suffi- 



. reduced by friction on, and gradual mixing with, the lower 



and so dashing upon the earth with that tremendous \ 



which gives them their destructive character, and of which hardly any 



I account hns yet been given. But it by no means follows that 



thin must always bo the case. In general, a rapid transfer, either way, 



in latitude, of any mass of air which local or temporary causes might 



would give a fearful exaggeration to its velocity. Wherever such a 

 mam should strike the earth, a hurricane might arise ; and should two 

 Mich mas-. - 'i mid-air, a tornado of any degree of intensity 



It from their combinati 



.Uiich this : I ' j.le cmmciV 



Hadli.t ' ' for the tiade winds (col. !l^ !l, mid di 



Dove in hi*- . tation, will readily occur to the reader. 



i e], when lait u Kiihject, in his 'Treatise on Me- 



and its development, as applied to 



this specific class of aerial movements by Professor Taylor, as affording 



< account of all the characters of cyclones." 



In the article WATI nsrot'Ts, the opinion has bcrii expressed, that 

 probably pin ninena of several distinct classes are at presci;: 

 founded together under that appellation. Sir .1. Ilcrschel, contravening, 

 as it would inion, now regards the mas of the 



nature of cyclom lington, as we have m !y din- 



eliminate* between them, at least as to form, on account of the 

 discuidal character of the one set uniiur 



figure of thcotlu-r; notwithstanding his admissions thai 

 hive the character* of whirlwinds, and exhil.il Hum nife.-tly when 

 they advance upon the land. It seems difficult to refer to the same 

 causes a disc of which the thickness or height is a very small fraction 



of it.i diameter, u in cyclones, and a slender column of which the 

 diameter i an equally small fraction ,.f the length or height, iw in the 



: outs observed on land by .Major Sherwill, and at sea by tin- 

 Hev. |ir. Sc.iroby. The former describes the powerful atti 

 which he n.iturafly attributes to . 



mountain Tonglo, for certain wateiy]mt& Thi U itron 

 rated by Rome fact* stated by another Indi.m 

 Montgo ' ., of the Trigonometrical 8ur> 



on the I'ir Punjal peaks of the Himalaya, 



elevations of from 13,000 to 15,000 feet, the electricity to be so 

 troublesome, even when then ' was nec*^ 



carry a portable lightning conductor for the protection of tl. 

 Still, 1: .lerspouts, if lechanical origin, if ' 



excessively rapid gyrations of cndcnMii<.; vapnur or closely a] 

 mated globules of water, might, and in all probability would, 

 powerful electric action. If their form be so sustained 

 friction of the particles must ensue, and a corresponding am. 

 electric: oped; the entire column would be strongly charged, 



and WOuM < '.vntually attract and be attracted by the ground. The 

 sudden precipitation of the !tcd effect 



electrical discharge and of tie M of the - 



let and friction \\ith I noss of the land, 



thing tends to show that our i rspouts are inexact, an 



the subject of their origin and nature :itnl id 



of the air, is in need of :>.sion which all the complex 



phenomena of nature require, and but few of them have roc; 



The force of the win.! :i..ti.v.l m; 



the means of measuring it u. In Mi. 



Piddington's Sailor's II '.)gue of other works 



Law of Storms will be found, and on that subject, and that of thu 

 winds in general, may be consulted (in addition to the work 

 memoirs which have been cited in this article*, Admit 



-',));!.( : and also Mr. W. li. Dirt's llarricanr 



. and his article on Atmospheric Waves in the ' 'lanital 



\\ INI )A(!K is the quantity by which i a gun, mortar. ..r 



howitzer exceeds that of the shot or shell which is to be discharged 

 from it. 



The deviations of shot and shells from a truly spherical Ggn; 

 the inequalities in the bore of the ordnance, were formerly consider- 

 able ; and on these accounts it was necessary to have a su. 

 difference between the piv.-uiurd diameters of the ball and i 

 order to ensu -ibility of making the former en 1 



latter : it followed, from the greatness of this difference, which in the 

 British service was about one-twentieth of tho diameter of th. 

 that much of the fired gunpowder escaped without producin 



on the shot, and that the latter was driven fi 

 of the surface of the bore to another; so that, on being e% 

 from the gun, it deviated widely from the intended dire 

 flight. 



From the year 1775, when I)r. Hutton made his firt PM 

 the velocities of shot, the disadvantage attending a great v 

 known, and a diminution of its quantity was proposed ; but the ] < 

 amount of the force lost by it Was not ascertained till the year- 

 and 17S6, when experiments were made for the purpose, in ] 

 uing that important circumstance. From these it aj>; 

 that about one-fifth of the charge of powder was lo>t by a w; 

 equal to '06 inch, or j'^d of the calibre ( = 2 inches), and a 

 amounting to between !th and ;th of the charge, was occasioned by rm 

 increase equal to ,jjth of an inch above the former win 



The correct geometrical forms which are now given to the halls, and 

 also to the bores, permit the windage to be reduce I . nv it* 



former value ; it now varies only from j^th to ; ? a tid of the . all ire, in ro 

 case exceeding 0'2 inch o . largest guns, and is still in p 



of reduction, as the manufacture of shot and shells advances in 

 precision. 



\V1XDLASS, an apparatus for raising a ship's anchors. It is placed 

 forward, as near to the hawse-pipe as convenient, A machine subject 

 to such violent strains as those which constantly affect a ship's cable 

 v. hc'ii in use, is necessarily built of the soundest oak and the best iron 

 in all the parts constructed of those materials, and is secured by stout 

 vertical pieces of timber called ' '/ . which rise above t! 

 serve the purpose i the enMe. which has first two or 



three turns round the barn] of the windlass. The cable is v 

 either by means of handspikes or a winch. As windlasses for ships are 

 so varied in form and priin iplcs, it is unnecessary to enter into d. t.iil. 

 These dimensions have of late years been greatly modified in conse- 

 quenceof the alteration of form in ships,. i ly steamers, win -re 



the narrowness of the bows admits but of little length to any cable- 

 raising contr: 'i TACKLE.] 



\V1 N" DM ILL is a building containing machinery for grinding corn, 

 pumping water, sawing wood, or for any purpose depending on wheel- 

 work, to which motion is conn. by the impulse of the wind. 

 Windmills arc of two kinds : in one, the wind is made to act upon 

 vanes or sails, generally four, which are disposed so as to revol 

 that action on an axis which is nearly horizontal, in a pl;n 

 nearly vertical ; and in the other, the axis of n-> 

 vertical, any point on the surface of the vane revolves in a horizontal 



