INTRODUCTION

	On perusing a paper descriptive of a canal projected by the Earl of Stanhope, in 1703, where many difficulties seem to arise, my thoughts were first awakened to this subject.

	The canal was intended for the purpose of conveying sea sand, as a manure, from Bude Haven, in Cornwall, to the high grounds near Houlfworthy and Hatherleigh, in Devonshire: on which the difference between the summit and lower levels was upwards of five hundred feet, and water extremely farce. Thus the disparity in the levels, and fearcity of water, which would require numerous and expensive reservoirs, banished every hope of a canal on the lock principle paying the subscribers.

	But to accomplish the work, it was proposed his Lordship  to form the ponds of canal at convenient distances, and unite them by iron rail-roads of a gradual and easy ascent,, on which boats of two tons were to be used; such boats navigating to the first rail-road, each of which was to be between a pair of wheels about six feet diameter, and conveyed by a horse to the next ascending level; then navigate to the succeeding rail-way, proceeding thus till the summit was attained.

	In a country with little water, and so great a disparity between the levels, and where coals could not be obtained to work steam engines, such a plan was certainly a good medium between navigation and cartage; but the whole trade was to go up the country, I was astonished to find, by calculation, that the hordes to perform the estimated four hundred tons per day, would amount to 7,000l. per annum on the rail roads only.

	Seeing these difficulties, and the necessity of an easy communication with hilly countries, I was impressed with the importance of an apparatus, which might transfer boats and their cargoes, to and from the different levels independent of locks and their demand of water, or rail-roads and their appendage of horses. 

	To produce such a machine, first thing that occurred to my imagination, was a water-wheel, to be put in motion by water from the upper level ; and, by that means, raise the boat on an inclined plane. But in great ascents, I found the wheel destroy more water than locks;  I then thought of a preponderating cistern of water, and was so certain of obtaining the power by that means, that I immediately conceived I had accomplished the machine; and having same communication with his Lordship, on the practicability of navigating vessels steam, I sent him a sketch of my plan: his Lordship, in answer, pleaded to compliment me on the thought; but at the same time informed me, it was the same as described by Mr. Edmund Leech, about sixteen years since. Here, for the first time, I discovered that the idea of a preponderating body of water, was by no means new. But, on investigating Mr. Leech's work, I found, that although our ideas of the cistern were nearly similar, yet we were far distant from the point to be attained; each using it on an inclined plane, without any certain mode of getting the boat in and out of the upper canal. I then changed the cistern from the inclined plane, to a perpendicular descent; because, in a perpendicular, the descending body acts with a force equal to its whole weight, friction excepted; while, on the plane, its descending force is lost in proportion to the angle ; after which, my whole difficulty has been to get the boats in and out of the upper canal, with certainty, ease, and expedition, so as to preserve a regular movement, and avoid much wear on the works. 

	To effect this, I have tried various experiments, and ultimately determined on the four modes described by the annexed Plates, each of which works with great certainty and ease, varying from double to single machines; and have at least established the practicability of passing boats to and from the different ponds of canals, independent of locks, rail roads, or steam-engines.
 
	Having accomplished a mode of passing the disparity of the levels, the next important consideration in reducing the expense of canals, was to crass rivers, or deep and wide valleys, without aqueducts. The following Plates will also exhibit the cheap mode by which the part of the work may be performed; and the reader will judge of the facility with which it may be executed.

	These points being gained, there is no doubt but much room is left for improvement, and that will be progressive as in all other machines: but the result of my experiments I now lay before the public; where, I hope, they will meet with a candid investigation, and the utility of small canals be deliberately considered.