“But that Fig. 56 may yet be more intelligible and useful, I have drawn on every side of it a scale, divided into equal parts, by which means we may ascertain the just proportion of any design we shall meet within it. “I have also marked every side of it with a letter, as =A=, =B=, =C=, =D=, the better to inform my reader of the use of the invention, and put him in the way to find out every design contained in that figure. “Example I.—Turn the side =A= to any certain point, either to the north, or to the window of your room; and when you have opened your glasses to an exact square, set one of them on the line of the side =D=, and the other on the line of the side =C=, you will then have a square figure four times as big as the engraved design in the plate: but if that representation should not be agreeable, move the glasses (still open to a square) to the number 5 of the side =D=, so will one of them be parallel to =D=, and the other stand upon the line of the side =C=, your first design will then be varied; and so by moving your glasses, in like manner, from point to point, the draughts will differ by every variation of the glasses, till you have discovered at least fifty plans, differing from one another. “Example II.—Turn the side marked =B=, of Fig. 56, to the same point where =A= was before, and by moving your glasses as you did in the former example, you will discover as great a variety of designs as had been observed in the foregoing experiment; then turn the side =C= to the place of =B=, and, managing the glasses in the manner I have directed in the first example, you may have a great variety of different plans, which were not in the former trials; and the fourth side, =D=, must be managed in the same manner with the others; so that from one plan alone, not exceeding the bigness of a man’s hand, we may vary the figure at least two hundred times; and so, consequently, from _five_ figures of the like nature, we might show about a thousand several sorts of garden-plats; and if it should happen that the reader has any number of plans for parterres or wilderness-works by him, he may, by this method, alter them at his pleasure, and produce such innumerable varieties, that it is not possible the most able designer could ever have contrived.” In reading the preceding description, the following conclusions cannot fail to be drawn by every person who understands it.