THRESHING MACHINE a rotary motion for this purpose, it was an easy matter to remedy the defects of his ma- chine and perfect the invention. In 1786 An- drew Meikle, a Scotchman, made an improve- ment on Leckie's machine by substituting a drum or cylinder with beaters attached to the circumference. He also applied rollers, con- nected by suitable mechanism to the driving gear, for feeding in the straw. "When operated, the drum was set in rapid motion by water or other power; the sheaves of grain, unbound and placed between the rollers, were fed in; and the beaters, revolving with great velocity on the periphery of the drum, beat out the grain from the heads and partially separated it from the straw. A patent was procured in Great Britain in 1788, when Mr. Meikle con- structed the first working machine, and added many new improvements, among which was the attachment of a fan mill, by which the grain was separated and cleaned from both straw and chaff. Though an invention of vast importance, saving annually millions of dol- lars in manual labor, and immensely increas- ing the product of grain throughout the civil- ized world, the simplicity of the threshing machine and the perfection of Meikle's inven- tions left little room for great modern improve- ments. Meikle's, with some modifications, was the first form of drum machine used in the Uni- ted States; but although the beater drum is still used in Great Britain, it has long been re- placed here by the spiked drum, which runs at a higher speed. This form of machine consists principally of a concave bed made of heavy plank lined with iron spikes arranged spirally, into which the drum, also armed with spirally disposed spikes, revolves. Such machines are capable of threshing 300 bushels of oats and over 100 of wheat in 10 hours. Most modern threshing machines have grain separaters at- tached, by which the grain is winnowed by a revolving fan, and also elevators which are long endless aprons moved on rollers, by means of which the straw is taken up into a mow or on to a stack. Numerous machines of this kind are employed in the United States, es- THRUSH 727 Geiser's Threshing Machine. pecially in the Mississippi and Ohio region. In many places where the farms are not large, it is the practice to employ threshers who move their machines, which are on wheels like those of a wagon, from place to place. One of these machines, patented by Peter Geiser, is represented in the engraving. M is the feeding board, and I the toothed drum, which throws the straw and threshed grain on to an inclined plane between I and B. Be- tween B and there is a rack, through which the grain falls, while the straw is moved for- ward on to the elevator N by means of a reciprocating rake. The grain falls back on an inclined plane to E, thence down over the fluted rollers E and F, where, receiving the air blast from the revolving fan H, the chaff is blown away, the grain passing down into re- ceptacles below. Lighter grains and seeds of weeds are blown further, beyond a screen, and are carried along with some good grain by an elevator, back to the thresher at L, by which means all the good grain is saved. THROCKMORTON, a N. W. county of Texas, drained by the Brazos river and its affluents ; area, 900 sq. m. ; returned as having no popu- lation in 1870. The surface is mostly broken and hilly, suited to grazing. In the south, near the Clear fork of the Brazos, is some good farming land. THROCMORTON, Sir Nicholas, an English states- man, born in London about 1513, died there, Feb. 12, 1571. He was page to the duke of Rich- mond till 1536, was afterward sewer to Henry VIII., and headed a troop at the siege of Bou- logne. Distinguished in the Scottish campaign under Somerset, he was knighted, received val- uable manors, and sat in parliament as mem- ber for Northampton. He was present at the death of Edward VI. in 1553, and, though _ a Protestant and aware of the movement in favor of Lady Jane Grey, favored the accession of Mary. He was arrested in 1554 as an accomplice in Sir Thomas Wyatt's rebellion, conducted his own defence, and was acquitted, but remanded to the tower on the ground that the verdict was contrary to law. He was re- leased in 1555, lived for a time in France, and in 1556 privately visited the princess Elizabeth at Hatfield, after whose accession he was made successively chief butler of England and chamberlain of the exchequer. As ambassador to France from 1559 to 1563, he favored the policy of Cecil, and intrigued to foment the civil religious war. He was imprisoned in 1569 for favoring a marriage between Mary queen of Scots and the duke of Norfolk, and never regained Elizabeth's confidence. THROMBOSIS. See BKAIN, DISEASES OF THE, vol. iii., p. 198. THRUSH, the common name of a very large family of dentirostral birds, which contains some of the finest songsters in various parts of the world. The bill is of moderate length, rather stout, slightly convex and keeled above, with sharp and notched tip ; at the base of ^the upper mandible on each side of the gape is a row of bristles much smaller than in the fly- catchers; nostrils at the base of bill, partly protected by a membranous scale ; wings toler- ably long, broad, usually rounded at the end,
