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does not stretch his paper, pins it down to his board with any drawing- pins that are at hand. These may possibly be pins with heads a sixteenth of an inch thick, beautifully milled on their edges and perfectly flat on their under and upper sides. Such pins would be shunned by any mechanical draughtsman who wished to keep the edges of his tee- and set-squares intact and free from notches. Pro- jecting the whole thickness of their heads from the surface of the paper, they would foul the edges of the tee- and set-squares and cause damage. The only kind of drawing-pin a mechanical draughtsman should use should have a head as thin as possible, without cutting at its edge, slightly concave on the under side or that next to the paper, and only so much convexity on its upper surface as will give it sufficient central thickness to enable the pin to be properly secured to it. There is neither sense nor reason in making the head of a drawing- pin half-an-inch in diameter if its circumferential edge does not bear on the paper when its pin is as far into the board as it will go. The purpose of the pin is to keep its head from rising from the surface of the paper, and it need only be long enough and strong enough to effect this. It is better practice to use four small, good-holding drawing- pins as shown in Fig. B, along the edge of a sheet of paper, than one large, clumsy, badly-made pin at each end of it. Suitable drawing-pins which answer every purpose required of them by the draughtsman are now to be obtained for half-a-crown per gross. 5. Paper. As the student from the very commencement of learn- ing to draw should study to acquire the good draughtsman's habits of work, and as one of these is the making of clear, sound lines in his drawing, whether in ink or pencil, it is advisable that he should