930 AN ACCOUNT OF THE 
necessary to have them supported at distances of 64 feet. The plan Thit 
on for constructing these supports, was I think happy, allowing as it did, 
sreat facility in laying and adjusting the rods of the same hypothenuse, 
being favorable to expedition, requiring little art in the making, nor much 
timber, nor even that weil seasoned, and above ail, being such as might be 
quickly constructed. 
6. ‘TuEse supports are represented Plate I. figs. t and 2.. ‘They consist 
of an upright, of from six inches to three feet in length, fashioned square, to 
within two inches of the bottom, where it has six equal faces: onthe alternate 
ones, are inserted legs at right angles, in all three, and these legs are each 
armed with a strong iron prong for taking hold of the ground, when laid 
for the rods. "These uprights are about three inches square, and there is a 
levelled groove on one face, reaching nearly the whole length in which 
slides loosely, a piece, having its upper end fashioned into a fork (fig. 3) 
the prongs of this: fork are broad, but short and separated about three 
inches. It ism this fork that the rod is to rest... 
@. TTuis sliding fork is to be steadied, when brought to the proper height 
by means of thin wedges driven between it, and the sides of the groove 
in which itslides. ‘The uprights being of three sizes, six, eighteen and thirty- 
six inches, and the stems allowing of a correct adjustment to ali the iatenge: 
diate heights, itis evident that these supports are equal to. all the inequali- | 
ties of ground, that can possibly-occur, and this I found to be the case, car-- 
rying on many of the hypothenuses to 1000 feet, and this ona surface so 
very unequal asthe Din, the fall of which too in four miles is between 
three and four hundred feet. 
