77 [ 32 1 
This line is a part of the unexecuted instructions of the Board. Ele- 
vated aqueducts and long tunnels, are now of so connnion occurrence 
in modern canalling as to be no material obstacle, especially since the 
application of the steam engine. Cut lines or routes of canals are 
compared, not only in j)oint of expense, but of ultimate practical 
economy, command of water, preservation of the works, accommo- 
dation to the inhabitants of the adjaceut country, &c. In this in- 
Btance, however reluctantly a majority of the Board consented to the 
investigation of this line, from its forbidding aspect, which it is but 
justice to them to remark; yet the reasons for it apjieai* to me sulh- 
cient, when recollecting that on Eric Canal, from Little Falls twelve 
miles down along the Alohawk, four times as much water is consum- 
ed, as the middle section uses per mile per minute; and know ing how 
difficult it is to make a canal tight, whicii is sustaitied along the rough 
shore of a river high enough to be out of reac h of freshets. Nor is 
it any easy thing to supply from a river having the characteristics of 
a torrent, by means of dams; and considering too the length of the 
ravine, there seemed to be reason for a comparison of a liije wiiich 
might possibly result in an escape fiom any serious difficulty. The 
boldness of the plan of crossing the Youghiogeny at the ele\ation of 
perhaps one hundred feet, to gain the valley of Sandy Creek, may be 
readily countenanced by the experience of England in like cases. 
The writer of these j)ages stood on the Aqueduct Pontcysyltc, over 
the river Dee. in North Wales. (130 feet high) while building, and a 
year afterwards saw it in full operation. Its aiches and trunk are of 
cast iron. (See plate 415, J\''nv Edinburg Ency.) 'I'he place of the 
tunnel in this instance will demand, no doubt, the best jiidgnient. In 
the want of a preference of this line, the canal would descend from 
about one-third the western elevation of the Lauiel, and regain the 
valley of the Youghiogeny not far from Connelsville. 1 he distatice 
is computed, from Bear creek to the mountain, 14 miles; and the 
saving in the length of the western section about twenty miles. And 
it is presumed the saving of exjjense will not be inconsiderable. — 
There arc three great points to be kept in view in deciding upon the 
line of the western section: directness, management, as well as com- 
mand of water, cost of the work, and uninterrupted operation. 
While the Board were fulfilling the orders of the Hon. Secretary of 
War, in examining the country between the Ohio and the Lake, their 
instructions had been so far executed on the summit ground, as to de- 
termine some of the most material points. I return, therefore, to the 
inquiry depending thereon. 
It was found that the Youghiogheny, at a certain ledge above the 
great falls designated by the Board, is below the base line 74.50 ft. 
The fork of the Little Youghiogheny - - - 57. 
The mouth of Snowy creek - - - - - 40.69 
The fork of Cherry Tree creek ., - . - SO.IS 
Armstrong's, on Little Youghiogheny - . - 46. 
Themouthpf Nest Lick run. on the Little Youghiogheny 16.28 
