Page:Cyclopaedia, Chambers - Supplement, Volume 2.djvu/948

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bears a greater part of the weight than the other, as being lower ; now, in fuch a cafe, the fpokes ot a dilhing wheel become perpendicular, and therefore have the greater! ftrength; whiift the oppofite wheel, being upon higher ground, bears a lefs part of the weight, and confequently the fpokes need not be at their full ftrength. Indeed, if wheels always turned upon fmooth and level ground, the fpokes ought to be ftrait upon the naves, or at right angles to their axes.

As to the axel-trees of wheels, they ought to be ftrait in all refpe&s, and at right angles to the (hafts, or to the pole. It would alfo be much more advantageous to make the four wheels of a coach or waggon large, and nearly of a height, . than to make the fore-wheels of only half the diameter of the hind-wheels, as is ufual in many places. Carriages too with four wheels have greatly the advantage of thofe with two : for in applying horfes to a cart, or chaife with two wheels, it is plain that the tiller carries part of the weight, in what manner foever it be kept in equilibrto upon the axel-tree. In going down a hill, the weight hears upon the horfc ; and in going up hill, the weight falls the other way and lifts the horfe, by which means pait of his force is loft. Befides, as the wheels fink into the holes in the road, fome times on one fide, fometimes on the other, the fhafts ftrike againft the tiller's flanks, which is the deftruction of many horfes. Add to this, that when one of the wheels finks into a hole or rut, half the weight will fall that way, whereby the cart will be in danger of being overturned.

We have a great many more obfervations concerning whcel- carriages in Dcfagulicrs's Experim. Philofoph. p. 201, feq. Blewing-V? heel, [Suppl.) a machine contrived by Dr. Defa- guliers for drawing out the foul air of any place, or for forcing in frefh, or doing both fucceflively without opening doors or windows. See Phil. Tranf. N° 437. The intention of this machine is the fame as that of Dr. Hales's ventilator, but not fo effectual, nor fo convenient. See Defagul. Courfe of Exper. Philof. Vol. II. p. 563—568. This wheel is alfo called a centrifugal-wheel, becaufe it drives the air with a centrifugal force. IF'ater-'WHEEL of a mill, that which receives the impulfe of the ftream by means of ladle-hoards or float-boards. Si the article Flo AT-boards, Append. . Mr. Parent, of the Academy of Sciences, has determined the

- greateft effect of an under- {hot wheel to be, when its velo- city is equal to the third part of the velocity of the water that drives it. See Machine, Append.

- In fixing an under-fhot wheel, the workmen ought to con- fider whether the water can run clear oft", fo as to occafion no back-water to ftop its motion. For a farther account of water-wheels, fee Defaguliers, Experim. Philof. Vol. II. p. 4.22, feq.

WHICKEN, a name fometimes ufed for the forbus, or quick- beam. See the article Sorbus, Suppl.

WHIN, or Gorse, a name ufed in fevcral parts of the king- dom for the ulcx or gen'ijla fpartium of botanifts. See the article Genista fpartium, Suppl.

WHIST, or Whisk, a well known game at cards. Several cafes of this game have been the objects of mathematical computations. Thus Mr. de Moivre has folved this problem : To find the odds that any two of the partners, that are

- pitched upon, have not the four honours? Mr. de Moivre concludes from his folution,

i°. That it is 27 to 2, nearly, that the dealers have not the

four honours.

2°. That it is 23 to 1, nearly, that the eldeft have not the

four honours.

3 . That it is 8 to 1, nearly, that neither one fide nor the

other have the four honours.

4 . That it is 13 to 7, nearly, that the two dealers do not

reckon honours.

5 B. That it is 25 to 16, nearly, that either one fide or th.

other do reckon honours, or that the honours are not equally

divided.

The (dme learned author alfo determines, that the odds for

the partners who are eight of the game, if dealers, againft . thofe who are nine, is nearly as 1 7 to u. ; But if thofe who

have eight of the game are eldeft, the odds will be 34 to 29.

And that without coiifidering whether thofe who are eight

are dealers, or eldeft, there is one time with another 7 to c,

nearly. But thofe who have furnifhed the author with the

data for the folution, not having ftated them fufficiently,

the conclufion is deemed erroneous ; but we know no body

that has endeavoured to rectify it.

We {hall here infert another problem.

1 o find the chance of the dealer's having four trumps.

One trump being certain, the problem is reduced to this, to

find what probability there is that in taking at random 12

cardsoutof 51, whereof i2are trumps, and 39 not trumps,

3 of the 11 (hall be trumps.

By Mr. de Moivre's rules it will be found, that the total of

the choices for the dealer — 92770723800 ; and that the

total of the chances for taking any 12 cards out of 51 ~ ■ ' 58753389900. 1" ne difference of thefe two numbers =

65982666100. The odds therefore will be 0277 ggrV, to

6598 fcV. y "

Or we may compute the chance of three players having 10* II, or 12 trumps among 39 cards. Then we i'hali find that the total of chances for taking 10, 1 1, or 12 trumps among 39 cards = 65982666100 ; and that all the chances out of 51 == 158753389900. The difference — 92770723800=:. all the chances for the dealer, and the odds will be 9277 &c. to 6598 c3V. as before.

The approximating ratios to the ratio of 9277 £sV. to 6598 &c, by Mr. Cotes's method, (fee Ratio, Si<ppl.) are, Ratios greater than true 2:1, 3:2, 10:7, 17 : 12, 24: 17, cSV. lefs than true 1:1,4:3, 7:5, 52:37, 97:69, &c. But it is to be obferved that the ratio 24 : 17, though ex- prcfled in much greater terms than 7 to 5, is extremely- little nearer the truth ; and the ratio 17 to 12 is not fo near as 7 to 5 ; which fliews that in practice we fhould only re- tain the primary approximations of Cotes's method, for the fecondary may lead us into error.

The bets for the dealer in this cafe, among the members of a great club, were formerly laid equal. But the vaft odds of above 40 per cent, may fhew how cautious gentlemen ought to be in laying bets without previous computation. The odds in money in this cafe, is,C I. s. d. -\

morethan< 140 11 ii'-Ctoioo/. left than t 140 11 n}}

WHORTLE, or Whortle-/wv, the Englifli name of a genus cf plants, called by botanifts vaccimum, or vitis id&a. Sec the article Vitis ideca, Suppl.

WIDGEON, in ornithology, the Englifh name of a bird of the duck kind, with a brown head, a white front, and a tail black underneath. See the article Duck, Suppl.

WIDOW- wa//, a name by which fome call the eneorum of botanical writers. See the article Cneqrum, Suppl.

WILLIAM, or Sw«if-WiLLiAM. See Sweet-/£7///W, fupra.

Sweet- Willi am of Barbadoes. Sec Sweet, fupra.

WILLOW {Suppl.)— Dutch or Sweet-WiT.iow, the name by which the myrica of botanifts is fometimes called. See the article Myrica, Suppl. and Append.

French-W illow, or Podded W iLi.o\v-herb, names given to the epilobium or chamttneriuni of botanical writers. See the article Chamsnerium, Suppl.

Willow -herb, the Englifh name of a genus of plants, called by botanifts falicaria. See the article Salicaria, Suppl.

WINCH, a popular term for a wlndlafs. See the article Windlass, Cycl.

Winch alfo denotes the crooked handle for turning round wheels, grind-ftones, C5V. Blanckley's Naval Expofitor.

WINCHING, in the manege, is faid of a horfe when he kicks, fpurns, or throws out his hind feet. Ruft. Diet, in voc.

WlND-fower, the Englifh name of a genus of plants, called by writers on botany anemone. Sec the article Anemone, Suppl.

Winn-feed, the name by which fome call the arclot'ts of bo- tanical authors. See the article Arctotis, Suppl.

WINDING of fill-. We have an excellent machine for this purpofe at Derby, contrived by Meflieurs Thomas and John Lomhe ; but as the proprietors are not willing that a defcription of it fhould be made public, the following ge- neral account of it muft fufficc.

It confifts of no lefs than 26586 wheels, and 97746 move- ments. One water-wheel communicates motion to all the reft of the wheels and movements, of which any one may be flopped feparately and independently of the 1 reft. One fire-engine conveys air to every part of the machine ; *«d one regulator governs the whole work. 73728 yards of filk are wound every time the water-wheel goes round, which is three times every minute ; fo that 318,504,960 yards of filk may be wound every day and night, and cenfequently 99>373'547i55° yards of filk in one year. See Defaguliers, Experim. Philofoph. Vol. I. p. 70.

VfJNTER-cheny. See the article Cherry, fupra.

WiiiTER-crefs. See the article Cress, fupra.

WiNTER-grcen. See the article Green, fupra.

WITCH-hazel. See the article Hazel, fupra.

WITHERING of a cow, is when, after calving, fhc does not caft her cleanfing, which if not timely -remedied will- kill her. Ruft. Diet, in voc.

WITHY, a large (pedes of willow, fit to be planted upon high banks and the fides of ditches, within reach of the water, or on the weeping fides of hills. Ruft. Di£t. in voc.

WOLF{%>p/.)— W0LF-/A the Englifh name of the lupus vmrinus or authors. See the article Lupus marinus, Suppl.

WOOD {Suppl.)~Almiggim-'W Don, See the article Almig- gim, Suppl.

WooD-bine, or WooD-bind, the Englifh name of a genus of plants, called by Tournefort peridymenum, but comprehended by Linnaeus among the knueras. See the articles Pericly- menum, Suppl. and Lonicera, Append.

WooD-m«, certain foreft-officers appointed to take care of the king's woods. Ruft. DicVin voc.

Woon-roof, or Wood-c^, the Englifh name of a senus of plants, called by botanifts afperula. Sec the artkb Aspe-

RULA, Suppl.

Wo en-