In changing the compass from a small to large radius, hold the legs together with one hand and spin the nut with the other, in order to save wear on the threads.

Adjusting the Compass

In changing the compass from a small to large radius, hold the legs together with one hand and spin…

"The simplest idea of a crank is that of a handle to a wheel; its action is familiarly illustrated in the process of drawing water from a well: the bent handle attached to the wheel is first pushed out, then pulled in the opposite direction, and thus a continued rotatory motion is produced upon an axle. The application of this principle to the steam engine, and the variations of pressure on the crank of a steam enginre, may be conveniently illustrated by curves." —Comstock, 1850

Crank

"The simplest idea of a crank is that of a handle to a wheel; its action is familiarly illustrated in…

Lines perpendicular to each other may be drawn by using a triangle in combination with the T-square. To draw a line perpendicular to a given line place a triangle against the T-square and move them together until the hypotenuse of the triangle matches the line. Turn the triangle on its right angled corner until the perpendicular line can be drawn on the hypotenuse of the triangle.

Drawing Perpendicular Lines Exercise

Lines perpendicular to each other may be drawn by using a triangle in combination with the T-square.…

An illustration of two men drawing on the a sidewalk after measuring a distance.

Men Drawing on Sidewalk

An illustration of two men drawing on the a sidewalk after measuring a distance.

The act of removing milk from the mammary glands of an animal, typically cows (cattle), water buffalo, goats, sheep and more rarely camels, horses and donkeys. Milking may be done by hand or by machine.

Apron Milking

The act of removing milk from the mammary glands of an animal, typically cows (cattle), water buffalo,…

A wrench with two serrated jaws, one adjustable, for gripping and turning pipe.

Adjustable Pipe Wrench

A wrench with two serrated jaws, one adjustable, for gripping and turning pipe.

One sort of pump once common worldwide was a hand-powered water pump over a water well where people could work it to extract water, before most houses had individual water supplies.

Hand Operated Pump

One sort of pump once common worldwide was a hand-powered water pump over a water well where people…

"For drawing ink lines other than arcs of circles, the ruling pen is used. It should be held as nearly perpendicular to the board as possible, bearing lightly against the T square or triangle, along the edge of which the line is drawn. After a little practice, this position will become natural, and no difficulty will be experienced." — Hallock, 1905

Ruling Pen

"For drawing ink lines other than arcs of circles, the ruling pen is used. It should be held as nearly…

"For drawing ink lines other than arcs of circles, the ruling pen is used. It should be held as nearly perpendicular to the board as possible, bearing lightly against the T square or triangle, along the edge of which the line is drawn. After a little practice, this position will become natural, and no difficulty will be experienced." — Hallock, 1905

Ruling Pen

"For drawing ink lines other than arcs of circles, the ruling pen is used. It should be held as nearly…

Spiral with lines AB and CD drawn on piece of paper shown flat.

Spiral Drawn on Piece of Paper Shown Flat

Spiral with lines AB and CD drawn on piece of paper shown flat.

Spiral with lines AB and CD drawn on piece of paper and rolled into a cylinder to form spiral running from A to D.

Spiral Drawn on Piece of Paper and Rolled

Spiral with lines AB and CD drawn on piece of paper and rolled into a cylinder to form spiral running…

John Trumbull (June 6, 1756 – November 10, 1843) was an American artist during the period of the American Revolutionary War famous for his historical paintings including his Declaration of Independence, which appears on the reverse of the $2 dollar bill.

John Trumbull

John Trumbull (June 6, 1756 – November 10, 1843) was an American artist during the period of the…

A woman drawing a picture of a map.

Woman Drawing

A woman drawing a picture of a map.