4*0 Major-General Roy’s Account of the 
On the face or exterior fide of each leg of all the {lands*, 
fixed as well as moveable, a plate of brafs is fcrewed near the 
bottom, with two holes in each, over a groove purpofely made 
in the wood underneath. By means of thefe plates, parallelopid 
leaden weights, about fourteen pounds each, having brafs pins 
with heads fuited to enter the holes, and fall down in the 
grooves, into a narrow-pointed part of them, are readily 
flipped on or off each leg. Thus every (land, exclufive of its 
own weight, which is about thirty-one pounds, being loaded 
with forty-two pounds of lead, is thereby rendered perfectly 
firm and heady. 
A number of wedges were alio 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. 
Notwithftanding all thefe precautions, it having been found, 
in the meafurement with the deal rods, that time was loft in 
levelling the hands, particularly in fttuations where the furface 
happened to be more than ufually uneven, or where it was of 
a loofe or fpungy nature; therefore Mr. Smeaton advifed 
(and no man’s advice is more deferving of attention), that deal 
platforms, handing on pickets driven into the ground, and 
properly levelled, fhould be ufed to receive the legs of the 
hands. Accordingly, for the operation with the glafs rods 
(table XIX.) twenty fuch triangular platforms made of inch 
deal, whole ftdes 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, fhort or long as the fttuation required, being 
driven into the ground, till their heads (by the carpenter’s 
i level) 
