87 L 32 ] 
not far from the first, into Dewlckinau's arm; and two, or a wide 
one, will be necessary. The inconvenience of narrow tunnels in 
causing; delay, is thns exemplified: If it be one mile through, and 
boats Can pass in half an hour, and are enterinj^ half an hour, others 
wait (in hour for their turn, which is six houis a day. and w hich 
diminishes the power of the canal, considered as a n)ai!ii»ie, one half. 
In an active trade the tunnel may as well be the gauge of all the rest 
of the canal, and a great saving of cost take place. In this coiintry, 
Nvherp so n)any are doing business on tiieir own account, delay atid 
hindrance ill accords with the industrious, persevering genius of the 
people: hindrance also occurs wht're a canal, being led through i-ock, 
is made narrow; or where aqueducts aj-e of single width, or the abut- 
ments of bridges are allowed to contract the trunk of the canal. It 
may be said, without hesitation, that a work like this in contemplation 
of the National Government, should be capable of two processions of 
bo.its, in opposite directions, from end to end; but the size of thoiti 
shoiild be adapted to the trade, and to the natural navigation whicli 
the canal connects togethei-. 
It thus aj)i)i'aring that the communication is practicable by the 
ordinary methods of supply, the natural iiosv and reserved bodies of 
water; the ])ractira! inquiry next occurs, whether the descent from 
the sumtnit level each way, so much in so short a distance, affords 
room for the locks? From the east end of the tunnel to the mouth of 
Crublrct, will be eight miles, the descent being 1,054 feet; it is 40 
in length for one descent. A lock of 100 feet, eight feet lift, wit!» 
its entrances, occupies 120 feet. Therefore, a succession of locks witli 
intermediate basins of £00 feet, will occupy the whole ground. On 
the west side the descent is 960 feet in six miles, op 33 feet fur one 
foot. It would indeed be very difficult to keep a canal in operation 
thus constructed; the reason is, that, in these successive basins, their 
depth, in relation to the entrances of the locks, is easily dej-anged. if 
a boat is going up, she checks the supply, and, at the same time, ano- 
ther draws from the source thus failing of supply: througiiout one 
hundred and five locks, and as many basins, there would be an itucs- 
sant fluctuation of this kind of trouble. To remedy it by a feeder 
along the whole way, parallel to the work, would involve the waste 
of water, did the ground permit; or, if the descent were made by a set 
of connected locks, four or six together, in order to extend the basins 
in this case to 1,000 feet, then occurs delay in passing, unless tlicre 
are parallel series; atid, for this, I fear our ravine of 40 feet will 
hardly afford room. 
There are indeed other methods of passing from one le\el of a canal 
to another; but it too often occurs that ingenuity is disappointed of 
fortunate results, from a want of that practical philosoi)hy which 
would have enabled them to calculate the strength of materials, and 
the resistance of friction in the movement of heavy bodies, and when^ 
ever improvements of this kind come from the hands of those who arc 
known to be versed in mechanical science, such is the natural fond- 
ness of inventive genius for its own offspring, that machines for a 
