William Farish: 'On Isometrical Perspective', Cambridge Philosophical Transactions, 1, (1822)

In models, and machines, most of the lines are actually in the three directions parallel to the sides of a cube, properly placed on the object. And the eye of the artist should be supposed to be placed at an indefinite distance, as before explained, in a diagonal of the cube produced. [...] It would not be difficult to devise rules for the representation of many other forms which might occur in objects to be represented. But the above cases are sufficient to include almost everything which occurs in the representation of models, of machines, of philosophical instruments, and, indeed, of almost any regular production of art.