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"Demention [sic] of a Thrashing Machine"

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Gilder Lehrman Collection #: GLC02794.177 Author/Creator: Place Written: [Scotland] Type: Document Date: [1800 ca.] Pagination: 4 p. 24.9 x 20 cm Order a Copy

Detailed description of James Tod's threshing machine.

Demention [sic] of a Thrashing Machine belonging to James Tod at Smeaton Shaw near Dalkeish (a Tenant of the Duke of Burgundy Constructed by Cha. Umphorston at Loanhead upon the estate of Sir John Clerk of Pennywick in Scotland--
No. 1 Lever) by which the machine is moved 13 feet 3 inces long fixed in the upright end of the large wheel, but as the horse drawn by traces one of which is fixed at the end of the lever and the other three feet from the end of it 11/2 feet must therefore be deducted, from the lever so that the horse walks in a circle of 23 1/2 feet diameter---
2nd. Large Wheel) fixed on the upright axle above the lever, 7 1/2 feet diameter to the outer extremity of the teeth, containing in its circomference [sic] 120 cast iron teeth, each tooth being nearly 2.1/2 inches from center to center 1.1/2 inches deep and 3 inches broad---
3rd. Horisontal [sic] lying axle) on the end of which is fixed a pinion of one foot in diameter of cast iron containing 15 teeth, mov'd by the big wheel, the other end of their axel goes into the barn and is made longer or shorter to said situations, in Tod machine is measured 16.1/2 feet long and make eight revolutions for one of the horse---
Nixt Machinery within the Barn
4th. Verticle wheel) fixed on the other end of this long horizontal axle within the Barn 4 feet in diameter over the teeth, containing on its circomference [sic] 90 cast iron teeth, each tooth being nearly the distant 1.3/4 inches from centre to centre 1 inch deep an 2.1/4 inches broad cast in six segment.
5th. Cast iron pinion) seven inches in diameter containing 10 teeth moved by the verticle wheel (4), this pinion is fixed on the end of a wooden axle 3 feet 7 inches long on which theres scutchers of the length of the axle are placed at equal distances from each other, their distance from the centre of the axle being 22.1/2 inches they are strenggthened by fillits of wood at each end on which is fixed a lining of ther deal, so that the scutchers are fixed upon a cylinder on the out side of which the scutchers project 3 inches, the breadth of the striking surface is therefor 3 inches, length as above 3 feet 7 inches, covered with strong meltd [sic] iron plate, the scutchers make about nine revolutions for one of the verticle whee and about 72 revolutions for one of the horse---
Note the above contain a description of the whole of the thrashing part of the machine, next follows the part which feed in and hold the corn in the straw for receiving the strokes of the scutcher---
6 On the horisontal [sic] axle 3) at a convenient distance from the vertical wheel (4) there is fixed two pullys [sic] or rather one pully [sic] with two channels or groovs [sic] of a larger and smaller diameter big 15 and 16 inches, over this pulley goes a leather strap which also goes over an other double pulley of 8 & 9 inches diameter, in the centre of this last mentioned pulley is fixed the axle of the under roller made of cast iron and fluted 3 feet seven inches long being the length of the scutchers, above this roller lyes [sic] an other of the same make and dimentions and of cast iron likewise, on the iron axles of both these [pulleys crossed out] rollers near the pulley are fixed two small cast iron pinions 4 inches in diameter and containing 12 teeth each which go into one another, the leather strap passing around the pulley on the horisontal [sic] axle (3) and round the pulley on the axle of the under roller turns it round with more or less velocity proportioned to the circomferences [sic] of the different groovs [sic] on which the strap is placed when the machine is required to go faster or slower, The upper roller is always mov'd with the same velocity with the under one, by means of the two small pinions of equal diameter and number of teeth, The upper roller has liberty to rise up a little in order to allow the handfulls of corn in the straw to pass betwixt the rollers, and it is held firm for receiving the strokes of the scutchers by the weight of the upper roller which can be adjusted by means of weights suspended to the end of short iron levers which press presses [sic] down the axle of the roller at both ends---
Immediately below the under roller is the breast faces with rolls iron, over which the corn in the straw immediately passes after going through the rollers, the breast generally approaches to within an inch of the scutcher being pressed with strings which are adjusted with screws and serve to give the straw as much resistance to the strokes of the scutchers as possible, but as the whole straw must pass through this interval if at anytime aportion of the straw is too thick to be admitted the spring give way which remove the breast to a greater distance from the scutcherss and allows the thick part of the straw to pass---
Experiments made for assertaining [sic] the power of the abover thrashing machine in presence of Sir John Clerke of Pennywick (Mr. Hutchison at the Iron mill near Dalkeish the ingenious contriver of the machine for assertaining [sic] the power necessary to draw plows vessels on canals [illegible].) Mr. Willm Mackie at Ormiston likewise some respectable farmer in the nneighbourhood and myself about the first of May last year 1794
1st
In the ordinary course of business two horses being yoked to the levers in 6-- hours thrased 26 bolls of oats equal to about 20 quarter of winchester measure----
2ndly
One horse being yoked in 6 minutes thrashed 24 sheavs [sic] of oats which produced half a boll or at the rate of 5 bolls P hour equal 63.3/4 winchester quarters
Note during the above experiment the oats wer [sic] fed into the mill by Sir John Clarke---
3rdly
An instrument as above mentioned having been procured for W. Hutchison one horse was yoked to the thrashing machine but on adjusting the instrument on the lever it was found necessary to shorten it three inches, that in this experiment the horse walked in a circle of only 23 feet diameter, he made three revolutions in in [sic] the minute, walking at the rate of 216.6/10 feet P minute of miles2.46/100 P hours the scutchers making 216 revolutions in the minute and moving with nearly 11.3/4 times the velosity [sic] of the horse, the machine thrashing at the rate of 4 bolls P hour or three winchester quarters the horse all the while pulling at the rate of 1.1/2 Hundred weight [illegible]---
Note the horse yoked by traces and moving in so small a circle cannot do near so much work as if he had been yoked by the neck to pull at right angles to the lever---
and lastly
The same instrument the same day and in presence of the above individuals was fixed to the muzzle of a two horse plow, the horses wer [sic] found to be pulling 3 lw. and moving at the rate of 2.5/8 miles P hour so that the power requisite to thrash 3 winchester quarters P hour with this machine may be estimated at the one half requisite to draw a well going two horse plough----

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