[IV]
MECHANICAL DRAWING: Continued
The next day, as they were about to resume their study, Ralph said: "There is so much to drawing that I hardly know where to begin, or what to leave out; but in shop drawing, a picture will not do; imagine an architect trying to build a skyscraper from a picture. The shop drawing must tell the mechanic everything he needs to know about the object he is making. He cannot keep running to the office asking questions; the drawing must answer them all. That is the reason why the draughting-room is such an important part of every manufacturing plant. Drawing is the language the designer uses to tell the workmen what he wants made. It is doubly important when the designer is hundreds or thousands of miles away from the workman.
"A battle-ship can be designed in Australia and built in England, so this language of the shop has grown to be a very interesting and important art. Every one who works with tools must learn it sooner or later, the sooner the better.
Fig. 23. Front and top views
"Usually it is necessary to represent even the simplest object by at least two views. For example, suppose I hand you this sketch a (Fig. 23), and tell you to make two out of wood. You wouldn't know what to do because no thickness is shown, but if I give you this sketch b, you would see immediately that it has practically no thickness and might be a sheet of paper. You learn that from the top view looking down on it.
Fig. 24. Showing necessity for top view