The Massachusetts Spy

[Communication.]

BALANCE LOCKS.

In the Spy of the 12th ult. I noticed an article which appeared originally in the American Farmer, giving an account of the Hydraulick Lift, or Balance Lock, by means of which, boats are raised and lowered from one level of a Canal to another, and not only the whole of the water usually required for lockage is dispensed with, but a considerable portion of the expense of the locks themselves is saved. At the same time I furnished another account of the same improvement, as used at the Ellesmere Canal in England, extracted from "Chapman's Observations on Canal Navigation."

More recently I have seen in the National Intelligencer; a specification of the same, signed by William Kenworthy, and by him deposited in the Department of State, for which he has received a patent, having affirmed, according to law, that he believes he is the original inventor thereof.

Where a person has made a useful discovery, the laws have very properly secured to him, the exclusive privilege of using it, for a specified time, on condition that it shall then revert to the publick. This is just; because, in making his invention publick, he gives an equivalent for the exclusive right. But where a man takes advantage of those laws, to appropriate to himself the sole benefit of an invention to which he has no claim, and to which any other member of the community has an equal right, it is an imposition which ought to be resisted, the more especially when it is of the importance of the one now under notice.

This improvement, precisely in the form described in Kenworthy's specification, has been used in England, as stated in my former communication, more than twenty years, and will probably be found very useful in this country, in the construction of Canals, where more water is needed for lockage than can be spared from mills. &c.

Any person wishing to make further inquiries on this subject, is referred to Rees' Cyclopedia, Vol. 6. under the article Canal.

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