James Madison Papers

To James Madison from Landon Carter, 19 February 1810

From Landon Carter

Va. Cleve 19. Febry 1810


Altho the subject of this Letter interests me individually, it yet involves public convenience enough to apologise in some sort for my intrusion, at this time of your deepest engagements. The present period points the attention of high commissioned characters to domestic structures, to such a degree, that I entertain a hope you will afford me your influencial patronage. I was indeed preparing to present myself before you but I am infirm and so much in the habit of indulgence as to dread a journey in the Winter season; unless induced to it by large prospects.

I have on hand—complete—a new constructed Lock, which in its plan baffles all attempt to enter by any other means than with its legitimate key. It is of plain, simple structure, as may be imagined from the agent of execution being a negroe carpenter, the number of whose ideas are very limited; and of course is chiefly of wood. I think the general utility of such a thing makes fit it should be exhibited, while Gentlemen are assembled from all parts of the nation, that it may be speedily disseminated. You have in your power to acquire a general sense of the estimation such an object will obtain and will perhaps consent to spare as much time as to write your ideas respecting the prospects of demand for permits under patent: Perhaps indeed Congress might be willing to make it a public property by purchase: It would suit me better, to sell out at once and the Public Would derive benefit from that mode as it would be a mean to bring it into a readier circulation.

The Locks now in use have wards contrived to obstruct the passage of Keys not accomodated with slit notches adapted to them; while the bolt is left free to be shot by any instrument which can be made to elude them: It is therefore that every attempt to vary the wards and the figure of the key is overcome by the ingenuity of man: The motion of the key, as respects the wards, also affords an opportunity, by impression, to mark the arrangement so as to imitate the key perfectly.

In my lock the wards connect with the bolt so as to hold it stationary untill the key arranges them to let it pass, and that arrangement is layed out after sections in the key ordered as fancy directs: The Lock therefore may be said to be made to the key & chance alone, hanging upon Millions of changes, can produce a key to the lock. My key consists of two parts, One to cooperate with the wards, having no horisontal motion, the other to force the driver upon the bolt. The slightest inequality in a key made as a copy, exact as may be to the eye, will effect the corresponding ward so as to leave it in the way, & no means exists to know which or how many are involved. Thus it may be seen that all the functions of the key are required to open the lock & it therefore cannot be picked—and those functions are so ordered as to cast the copier into the wide region of chance to find his purpose.

As no invention can be altogether original but that some similar Idea had prior existence, so do not I pretend to such unity in the present case: The arrangement of the same ideas may be new & more effective in operation; which is all that can be expected from the Inventor. If I can know the probable time Congress will adjourn I could regulate my motions accordingly; to you I shall be indebted for some information.

Under a full impression you will pardon me for giving you this trouble I will conclude with a repetition of my request that you will honor me with your patronage. I am mo: respectfully Sir yr. Obt.

L. Carter1

P. S. My address—mail to K. G. Cthouse


1Landon Carter (1751–1811) of Cleve in King George County served in the Virginia House of Delegates, 1780–81 (Lucien Beverley Howry, “Some Carters of ’Cleve,’ King George County, and Their Descendants,” VMHB description begins Virginia Magazine of History and Biography. description ends , 44 [1936]: 343; Swem and Williams, Register description begins Earl G. Swem and John W. Williams, eds., A Register of the General Assembly of Virginia, 1776-1918, and of the Constitutional Conventions (Richmond, 1918). description ends , p. 357).

Index Entries