3io] WEE able to plough them up, shortly before their seeds are formed, or at lenst previously to their attain- ing to a state of maturity. — T'le small seeds of weeds, that are m - parated in winnowing grain, ought to be carefully burnt ; because, ■when thrown upon dun^^-hills, and ftfterwards spread on land among manure, they vegetate with in- creased luxuriance. Perennial weeds are extermi- nated with the greatest difficulty ; as they strike very deep rout. The usual method of extirpating them, Ss ' that of bringing them to the surface by the plough ; after which they are gathered by hand : but, as this mode is very expensive, it vi be more advantageous to cut them half-through, about the mid- dle of June, or when they are in full vigour : for the sudden inter- ruption of their cifcnlating sap causes that fluid to stagnate in tlie roots ; in consequence of which the plant generally perishes : thus, such weeds may be colle6led by means of Mr. Sandilands' IFrack-Har- roTV, (see vol. ii. p. 432) ; then btrriit, and strewed on the land by ■way of Manuke.—- See also vol. iii. p. 159. ' - IVecds often abound in flie beds of navigable canals and rivers. As their eradication, however, is tedi- ous, and sometimes occasions con- siderable expence, M. Dk Betan- cooRT Molina, in , pre- setTted to the Society for the En- couragement of Arts, &c. a model of a machine designed to mow or cut fliem, so that they may then be carried down with the stream ; or, if the current be not sufficiently ra^id for that purpose', tiiey may be colle6ted on the surface of the watdr, and employed as manure. t«or tl4« contrivance,. he was re^ 1 J . WEt warded with the premium of firty guineas ; but, as a plain descrip- tion would not convey an adequate idea of the principles on which it !-> constmcted, we refer the reader to the 14th volume of the " Trati' saclions" of that Society, where a complete account is inserted, and illustrated with an engraving. "Weevil. See Corn-chafer, WEIGH, or Wey, a species of provincial English weight, employ- ed for cheese, wool, &c. : it con- tains 256 lbs. avoirdupois. A weigh of corn should comprise 40 bushels ; that of barley or malt, amounts to 6 quarters ; but in Essex, and some other counties, a ivel^h of cheese consists of SOOlbs. WEIGHl', denotes a method of ascertaining the quantity of any solid or fluid body, by means of the balance, or otherwise. Having already stated, in the articles Avoirdupois, Troy- weight, Clove, &c. the different weights used in England, we shall only remark, that various statutes have been enafted, with a view to regulate the uniformity of weights and measures ; but the wisdom and accuracy of those laws have not yet produced the desired clfec-tj and so prevalent is the force of ha- bit, that the old weights are still em[)loyed in many parts of the kingdom, to the great detriment and confusion of commerce. Hence, ingenious mathematicians have pro- posed various schemes for intro- ducing a more uniform scale in weights and measures; the prin- cipal of which are the fullowing : In the year 1779, t'^^ Society for the Encouragement of Arts, &c. conftrred a bounty of 30 gui- neas on Mr. Thomas Hatton, for his " Attempt tojind, hij Approii* viatLon, an Universal Standard."-^ -Mr.
