production.  While I withhold my assent, however, from this hypothesis, I must deny it to every other I have ever seen, by which their authors pretend to account for the origin of shells in high places.  Some of these are against the laws of nature, and therefore impossible; and others are built on positions more difficult to assent to, than that of De la Sauvagiere.  They all suppose these shells to have covered submarine animals, and have then to answer the question, How came they fifteen thousand feet above the level of the sea?  And they answer it, by demanding what cannot be conceded.  One, therefore, who had rather have no opinion than a false one, will suppose this question one of those beyond the investigation of human sagacity; or wait till further and fuller observations enable him to decide it.

Chanteloup.  I heard a nightingale to-day at Chanteloup.  The gardener says it is the male, who alone sings, while the female sits; and that when the young are hatched, he also ceases.  In the boudoir at Chanteloup, is an ingenious contrivance to hide the projecting steps of a staircase.  Three steps were of necessity to project into the boudoir:  they are therefore made triangular steps; and instead of being rested on the floor, as usual, they are made fast at their broad end to the stair door, swinging out and in, with that.  When it shuts, it runs them under the other steps; when open it brings them out to their proper place.  In the kitchen garden, are three pumps, worked by one horse.  The pumps are placed in an equilateral triangle, each side of which is of about thirty-five feet.  In the centre is a post, ten or twelve feet high, and one foot in diameter.  In the top of this, enters the bent end of a lever, of about twelve or fifteen feet long, with a swingle-tree at the other end.  About three feet from the bent end, it receives, on a pin, three horizontal bars of iron, which at their other end lay hold of one corner of a quadrantal crank (like a bell crank) moving in a vertical plane, to the other corner of which is hooked the vertical handle of the pump.  The crank turns on its point as a centre, by a pin or pivot passing through it.  The horse moving the lever horizontally in a circle, every point of the lever describes a horizontal circle.  That which receives the three bars, describes a circle of six feet in diameter.  It gives a stroke then of six feet to the handle of each pump, at each revolution.

Blois.  Orleans.  June 9, 10.  At Blois, the road leaves the river, and traverses the hills, which are mostly reddish, sometimes gray, good enough, in vines, corn, saintfoin.  From Orleans to the river Juines, at Etampes, it is a continued plain of corn, and saintfoin, tolerably good, sometimes gray, sometimes red.  From Etampes to Etrechy, the country is mountainous and rocky, resembling that of Fontainebleau. Quere.  If it may not be the same vein?

LETTER LVIII.—­TO WILLIAM CARMICHAEL, June 14, 1787