the right hand piece be the cross grained one, when the air is
very moist, it lengthens, and forces its companion to form a kind of
interior annulus of a circle on the left. When the air is dry, it
contracts, draws its companion to the right, and becomes itself the
interior annulus. In order to show this dilatation and contraction, an
index is fixed on the upper end of two of the slips; a plate of metal
or wood is fastened to the front of the plinth, so as to cover the two
slips from the eye. A slit, being nearly the portion of a circle, is
cut in this plate, so that the shank of the index may play freely
through its whole range. On the edge of the slit is a graduation. The
objection to this instrument is, that it is not fit for comparative
observations, because no two pieces of wood being of the same texture
exactly, no two will yield exactly alike to the same agent. However, it
is less objectionable on this account, than most of the substances
used. Mr. Rittenhouse had a thought of trying ivory; but I do not know
whether he executed it. All these substances not only vary from one
another at the same time, but from themselves at different times. All
of them, however, have some peculiar advantages, and I think this, on
the whole, appeared preferable to any other I had ever seen. Not
knowing whether you had heard of this instrument, and supposing it
would amuse you, I have taken the liberty of detailing it to you.

I beg you to be assured of the sentiments of perfect esteem and respect
with which I have the honor to be, Sir, your most obedient, and most
humble servant.

TO JOHN JAY.

PARIS, December 31, 1786.

SIR,--I had the honor of addressing you on the 12th of the last month;
since which, your favor of October the 12th has been received,
enclosing a copy of the resolution of Congress for recalling Mr. Lambe.
My letter by Mr. Randall informed you that we had put an end to his
powers, and required him to repair to Congress. I lately received a
letter from him, dated Alicant, October the 10th, of which I have the
honor to enclose you a copy; by which, you will perceive that the
circumstance of ill health, either true or false, is urged for his not
obeying our call. I shall immediately forward the order of Congress. I
am not without fear, that some misapplication of the public money may
enter into the causes of his declining to return. The moment that I saw
a symptom of this in his conduct, as it was a circu