WIND-MILL. 



a rope attached to the end of the ladder. This capftan is 

 moveable, and is faftened at pleafure to any one of the pofts 

 which are fixed in the ground. 



The internal raechanifm of a port wind-mill is exhibited 

 mjig. 3. Plate II. Wind-Mill. A H O is the upper room ; 

 Hoz the lower one ; A B the axis pafling through the mill ; 

 S, T, V, W, the fails, covered with canvas, fet obliquely to 

 the wind, and turning round in the order of the letters in 

 fig. I ; C the cog-wheel, having about forty-eight cogs, 

 which carry round the lantern £, having eight or nine 

 rounds, together with its fpindle G N ; K is the upper mill- 

 ftone, and L the lower one ; Q R is the bridge fup- 

 porting the axis or fpindle G N ; this bridge is fupported 

 by the beams c and X Y, wedged up at c and Q ; 2 Y is 

 the lifting-tree, which ftands upright ; a b and ef are 

 levers, whofe centres of motion are a and u ; f g h i is a 

 cord, with a flone, i i it goes about the pins^ and h, to wind 

 up and raife the ftone at pleafure. The fpindle / N is 

 fixed to the upper miU-ftone K, by a piece of iron called 

 the rynd, and fixed in the lower fide of the ftone, which is 

 the only one that turns about, and its whole weight refts 

 upon a hard ftone, fixed in the bridge Q R at N. The trundle 

 E, and axis G /, may be taken away ; for it refts by its 

 lower part at / by a fquare focket, and the top runs in the 

 ;dge of the beam tv. By bearing down the end/ of the 

 lever/ e, b is raifed, which raifes a Y, and this raifes Y X, 

 ivhich lifts up the bridge Q R, with the axis N G, and the 

 jpper ftone K ; and thus the ftones are fet at any diftance. 

 rhe lower immoveable ftone is fixed upon ftrong beams, and 

 s broader than the upper one : the flour is conveyed through 

 :he tunnel « into a cheft ; P is the hopper, into which is 

 put the corn, which runs along the fpout r into the hole t, 

 ind fo falls between the ftones, where it is ground. The 

 ixis G / is fquare, which fliaking the fpout r, as it goes 

 •ound, makes the corn run out ; r j is a ftriiig going about 

 :he pin s, and ferving to move the fpout nearer to or farther 

 "rom the axis, fo as to make the corn run fafter or flower, 

 iccording to the velocity and force of the wind. And 

 when the wind is great, the fails S, T, V, W, are only in 

 3art or one fide covered ; or perhaps only one half of 

 :wo oppofite fails. Toward the end B of the axis another 

 ;og-wheel may be fixed, with a trundle and mill-ftones, 

 ike that already defcribed ; fo that the fame axis moves 

 ;wo ftones at" once; and when only one pair is to grind, 

 he trundle E, and axis G /, are taken out from the 

 Jther ; xy / is a girt or gripe of pliable wood, fixed at the 

 !nd X ; and the other end / is tied to the lever /5 m, moveable 

 ibout k ; and the end m being put down, draws the gripe 

 t y I clofe to the cog-wheel ; and thus the motion of the 

 nill is ftopped at pleafure ; /i ^ is a ladder for afcending to 

 he higher part of the mill ; and the corn is drawn up by 

 neans of a rope, rolled about the axis A B, when the mill 

 s at work. 



The ftrufture of the mill-ftones, or grinding parts, is the 

 ame as the water-mills. See Mill. 



It is plain that this conftruftion confines all the machinery 

 o the two chambers, or that part of the mill which 

 s poifed upon the vertical poft ; hence this kind of wind- 

 nill is unfit for any other purpofes than that of grinding 

 :orn, and for expreffing oil, becaufe there is fo httle room 

 or the machinery. The Dutch, who are famous for wind- 

 nills, make them fometimes with a very large poft, which 

 las a hole down through the centre of it, like a trunk, and 

 hrough this, a perpendicular axis paffes to convey the 

 jower of the mill down into a buildmg below, and upon 

 he top of which, as a roof, the fouBclation-beams of the 



poft are fixed. ( See/f^. 4. ) In this way, the mill is applied 

 to faw wood, or to make paper, or any other purpofe ; but 

 the conftruAion is complicated, and lefs effeftive than the 

 other kind of mill, in which only the head or top turns 

 round, as we ftiall now defcribe. 



The Smock-Mill. — This is the beft kind of mill, becaufe 

 the building which contains the machinery may be made of 

 any required dimenfions, the fails and turning cap being all 

 at the top of the houfe. Fig. 3. in Plate I. Wind-Mill, 

 IS a vertical feftion of one of thefe mills. K K are the 

 walls of the houfe, and O O ftrong timbers forming a roof ' 

 to it ; upon thefe eight principal timbers H are erefted, to 

 form an oftagonal pyramid of carpentry, the fides of which 

 are filled up by diagonal bracing, and fmall uprights to 

 nail the boarding to. 



The four fails are fixed on an iron axis B N, by fcrewing 

 them to an iron crofs formed at one end of it. Two of 

 thefe fails are marked A A ; but the other two are end- 

 ways, and cannot be feen. Upon the axis within the mill 

 the cog-wheel C is fixed ; and this turns a trundle or lantern 

 D, fixed on the upper end of a ftrong vertical ftiaft, E E, 

 extending from the top to the bottom of the mill, to turn 

 the machinery : on the lower end of it is a large wheel,//, 

 which turns two pinions, g g, upon the fpindles of the 

 mill-ftones i h. Thefe are on the fame conftruftion as thofe 

 defcribed in our article Mill, to which we refer. At / is a 

 wheel upon the main axis, giving motion to a pinion on a 

 horizontal ftjaft or roller, k, which has a rope wrapped 

 upon it, to wind up the facks of corn. The wheel / alfo 

 turns a fimilar horizontal axis with feveral wheels, to receive 

 endlefs ropes for turning the bolting and drefling machines. 

 We will now enter more fully into the mechanifm of the 

 upper part of the mill, which is called its head or cap, 

 marked G, and contains the axis B N. This is fupported 

 upon bearings, one being near its fails, and the other at 

 its extreme end, as is ftiewn mjig. 5. Plate II. Wind-Mill, 

 which is an horizontal feftion of the head, (hewing the cir- 

 cular kirb, or wooden ring, K, and the framing which ig 

 bolted upon it to fupport the axis. 



The conftrudlion of the axis is ftiewn \n Jig. 6. of the 

 fame plate. It confifts of an oftagonal iron (haft with two 

 cylindrical necks at c and d, where it refts upon its bearings. 

 At the end it has a kind of box, which has two mortifes, 

 e and/, through it in perpendicular direftions to receive the 

 fails. At the back of one of thefe mortifes, and the front of 

 the other, a projedling arm is left in the cafting to receive 

 fcrew-boks, which hold the fails faft in the mortifes. The 

 cog-wheel is fixed on by bolting its arms againft a flanch C, 

 caft on the axis. The fails are braced by a rope-ftay to 

 each arm, proceeding from the end of a pole, which is fixed 

 at the end of the caft-iron axis. Each fail is formed of a 

 fail-cloth, fpread upon a kind of lattice-work or framing, 

 compofed of rails mortifed into the arms of the fails. The 

 plane of this frame is inclined to the plane of the fails' mo. 

 tion at fuch an angle, that the wind blowing in the direftion 

 of the axis afts upon the fails as inclined planes, and turns 

 them about with a power proportionate to the fize of the fails 

 and force of the wind. It is neceflary, as the wind changes its 

 direftion, to turn the fails about, that the axis may be always 

 in the direftion of the wind. ( See^g. 3. Plate I.) This mo- 

 tion is effefted by turning the head of the mill round upon 

 the fixed part, on a circle or kirb at the top of the frame com- 

 pofing the houfe of the mill. At the bottom of the frame of the 

 wood-cap is a circular or moveable kirb, between which and 

 the fixed kirb a number of rollers are placed ; and the move- 

 able kirb of the cap lie* upon thefe rollers, which sre kept 



equidiftant 



