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.
AD
Lectorem Perspectivæ studiosum.
Ars Perspectiva, oculum, licet sagacissimum inter sensus nostros exteriores, mirabili cum voluptate decipit; eademque necessaria est iis, quibus in pingendo, tum singulis figuris positionem ac deformationem suam congruè tribuere, tum colores & umbras, magis vel minus intendere aut remittere, prout oportet, curæ est. Ad id autem sensim sine sensu illi perveniunt, qui solo studio Graphidis non contenti, singulis Architecturæ Ordinibus exactè deformandis assueverint. Nihilominus, inter multos qui opus hujusmodi magno impetu aggressi hucusque fuerunt, paucos numeramus, qui animum ipso statim initio non desponderint, ob magistrorum librorumque penuriam, ordinatè ac perspicuè docentium opticas projectiones, à principiis hujus artis, usque ad omnimodam perfectionis consummationem. Quum autem sentiam, longâ multorum annorum exercitatione, me non minimam facilitatem in hac disciplina mihi parasse: censeo Studiosorum voluntati me satisfacturum, eorumque profectui consulturum, si methodos expeditissimas in lucem proferam, ad singulorum Architecturæ Ordinum opticas delineationes perficiendas, adhibitâ communi regulâ, ex qua omnia linearum occultarum offendicula sustulimus. Deinde, si tempus & vires ad aliud Opus conscribendum Bonitas Divina dederit, projectiones quascunque absolvemus regulâ qua in præsentia uti soleo, ac multò facilior & universalior est regula communi & vulgata, quamvis hæc sit fundamentum alterius. Itaque, Lector studiose, constanti animo negotium tuum suscipe; ac lineas omnes tuarum operationum, ad verum oculi punctum ducere, ad gloriam scilicet DEI O.M. tecum omninò decerne. Sic votis honestissimis, ut auguror tibi ac spondeo, feliciter potieris.
TO
The Lovers of Perspective.
The Art of PERSPECTIVE does, with wonderful Pleasure, deceive the Eye, the most subtle of all our outward Senses; and is very necessary to be known of all, who in Painting would give a due Place and Proportion to their Figures, and more or less Strength requisite to the Lights and Shades of the Picture. This might be insensibly attain’d, if Persons, not content with the Study of Drawing only, would accustom themselves exactly to delineate the several Orders of Architecture. Nevertheless, among many who have hitherto vigorously undertaken this Work, there have been but very few, who have not been in a manner quite discourag’d, through want of Masters and Books to teach them clearly and methodically the Rules of Perspective-Projections, from the first Principles of the Art, to the entire Perfection thereof. Wherefore, apprehending that by long and constant Practice in Works of this kind, I had acquir’d a Method to facilitate the same; I judg’d it might be for the Satisfaction and Advantage of the Studious, to publish the shortest way for designing in Perspective the several Orders of Architecture, by a common and easy Rule, free from the Incumbrances of occult Lines. But if it please God to give me Life and Health to compose another Book, I shall therein shew the Method of putting Works into Perspective by the Rule I make use of at present, which is more easy and general than the common way, though this be the Foundation of the other. Therefore, Reader, my Advice is, that you chearfully begin your Work, with a Resolution to draw all the Lines thereof to that true point, the Glory of GOD; and I durst predict, and promise you good Success in so honourable an Undertaking.