Chap. XXIL Of the Turnup-Drill 3 79 



Holes fhould make thefe very fmall Limbers the 

 weaker in that Part. C, the Plank, Two Feet and 

 an Inch long, Five Inches broad, and an Inch and a 

 quarter thick. D, D, the Two double Standards, 

 or Two Pair of Standards, placed into the Plank 

 with Shoulders above, and Tenons pinn'd underneath 

 the Plank, and are Thirteen Inches high above it : 

 Thefe ferve for a Pair of Marking-wheels, when 

 Turneps are drill'd on the Level, to keep the Rows 

 all parallel, and at what Diftance you pleafe, by 

 fetting them according to the Rule already laid down. 



Sometimes we place the double Standards into the 

 Plank of the Wheat-drill, in the fame manner that 

 thefe are placed. 



We take off the inner Edge of each Standard at 

 the Top, as at b b and b b, for the more eafy Admifiion 

 of the Spindle of the Marking-wheels into the Forks: 

 This Spindle is kept in its Place by Two of the fame 

 fort of Wreaths, and placed in the fame manner as 

 thofe defcrib'd for the fore Hopper of the Wheat- 

 drill. 



Such Marking-wheels are necefTary for drilling upon 

 the Level ♦, but not for drilling upon Ridges. 



E is the Beam, Two Feet Two Inches and an half 

 long, Four Inches broad, and Two Inches thick: It 

 is thus broad, that the Screws which hold on the crofs 

 Piece F, may be farther afunder : The Screws mud 

 be placed as near as may be to the Oiitfides of the 

 Beam, and at equal Diftance from each Side of the 

 crofs Piece; by which means the Standards are kept 

 the firmer from Turning. 



The Diftance between the Plank and the crofs Piece 

 is Eleven Inches. The Bteadth of the crofs Piece is 

 Two Inches and a quarter. This crofs Piece is (hewn 

 apart in Fig. 2. where its Two Standards A B, are each 

 Seventeen Inches long Cor high), and each on its fore 

 Side and hinder Side One Inch and a quarter broad, 

 and nearly Three quarters of an Inch thick : They are 



ihoulder'd 



