VERTICAL.-Upright or perpendicular. Vertical and perpendicular are not synonymous terms.

VERTEX.-Sce Angle, Quadrilateral, Triangle. The vertex of a solid is the point in which its axis intersects the lateral surface.

VIEW. See Elevation. Views are called front, top, right or left side, back, or bottom, according as

they are made on the different planes of projection. They are also sometimes named according to the part of the object shown, as edge view, end view, or face view.

WORKING DRAWING.-One which gives all the information necessary to enable the workman to construct the object.

A free-hand drawing is executed with the unaided hand and eye, without guiding instruments or other artificial help. It is necessary to be known that all drawing required cannot possibly be done by rule and compass, but that some portions must be drawn “freehand," trusting to the eye alone.

Hence, it is important that the student should be able to sketch at sight from objects he may see, or to draw roughly, with a piece of chalk or a pencil, pieces of mechanism required to be represented.

Practice in free-hand should go along with mechan ical drawing as progress is made, and thus cultivating. both branches equally.

"A simple sketch will often," as has been rather roughly said, "express more than yards of talk."

Even a slight sketch refreshes the memory, and in the case of the preparation of a complete set of drawings, with a view to the making of a thoroughly finished mechanical drawing, the proper course to pursue is, to make a general sketch, letter the various parts for reference, and then prepare a series of detailed sketches, similarly lettered, and diffuse with dimensions.

Everyone, whatever his specialty, feels to-day that the ability to sketch rapidly and clearly is among the absolute necessities for correct and prompt transactions of business, in giving and executing orders and doing business with persons outside his profession.