4 1 o Major- General R o y ' s Account of the 



On the face or exterior fide of each leg of all the f^ands, 

 fixed as well as moveable, a plate of brafs is fcrewed near tl^er 

 bottom, with two holes in each, over a groove purpofely made 

 in the wood underneath. By means of thefe plates^ parallelopici 

 leaden weights, about fourteen pounds each, having brafs pins 

 with heads fuited to enter the holes, and fail down in the 

 grooves, into a narrow-pointed part of them,, are readily 

 flipped on or off each leg. Thus every ftand, excluiive of its 

 own weight, which is about thirty-one pounds, being loaded: 

 with forty-two pounds of lead, is thereby rendered perfedlly 

 firm and fteady. 



A number of wedges were alfo prepared, and always ready 

 to be placed under the legs ; by means of which, and a fpirit 

 level laid on the table, its plane is brought to the proper - 

 pofition. 



Notwithdanding all thefe precautions, it having been found,. 

 in the meafurement with the deal rods, that time was loft ia> 

 levelling the ftands, particularly in fituations where the ifurface 

 happened to be more than ufually uneven, or where it was gf 

 a loofe or fpungy nature; therefore Mr, Smeaton advifed; 

 (and no man's advice is more deferving of attention), that deal 

 platforms, ftanding on pickets driven into the ground, and 

 properly levelled, fhould be ufed to receive the legs of the 

 ftands. Accordingly, for the operation with the glafs rods 

 (table XIX.) twenty fuch triangular platforms made of inch 

 deal, whofe fides were each three feet two inches in length, 

 and void in the middle, were provided ; as alfo a number of 

 beech-pickets, about an inch and a half fquare, and of dif- 

 ferent lengths, from feven to twelve or fourteen inches. Three 

 of thefe pickets, ftiort or long as the fituation required, being 

 driveo into the ground, till their heads (by the carpenter's . 

 I level) 



