ADVICE to BEGINNERS.

The Perspective of Structures here treated of, can have no Grace or Proportion, without the Help of Architecture. ’Tis therefore absolutely necessary, that you employ yourself for some time in Drawing, and the Study of that Art; till you can readily describe the Plan of any Upright, and from thence project the Section or Profile, as is shewn through the whole Course of this Work; and more particularly, in the Sixty-eighth and Seventieth Figures: Forasmuch as the proper Depth of each Part of the Perspective, is determin’d by the Plan and Profile thereof.

I shall add this one thing more, which is indeed of the last Importance; to wit, that you endeavour to understand the Second Figure throughly, before you proceed to the Third; and so of the rest: they being dispos’d in such Order, that the Knowledge of the preceding Figure is always necessary to a right Understanding of that which follows. If you meet with any thing which at first seems difficult in the Description, a diligent Inspection of the Figure may relieve you: And on the other hand, if you find not in the Figure every thing you desire, you may have Recourse to the Explanation. What Errours you discover in the Work, I hope you’ll generously overlook and pardon.