A compleat treatise on perspective, in theory and practice; on the true principles of Dr. Brook Taylor. Made clear, in theory, by various moveable schemes, and diagrams; and reduced to practice ... Containing diagrams, views, and original designs, in architecture, &c. ... All originals; / invented, delineated, and, great part, engraved by the author, Thomas Malton.

  • Thomas Malton
Date:
1778
Catalogue details

Licence: Public Domain Mark

Credit: A compleat treatise on perspective, in theory and practice; on the true principles of Dr. Brook Taylor. Made clear, in theory, by various moveable schemes, and diagrams; and reduced to practice ... Containing diagrams, views, and original designs, in architecture, &c. ... All originals; / invented, delineated, and, great part, engraved by the author, Thomas Malton. Source: Wellcome Collection.

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    vifions for the Mouldings, &c. and producing SI, &c. to the Vanifhing Line • then, Lines drawn from each divifion, on RS, to the refpedive Vanilhing Point ot each Jamb, wftl divide each Window into its feveral divifions of Mouldings Sa(h Squares, &c. and, by the fame means, all the Curves, in the Mouldings &c* at the top, may be defcribed with the greateft accuracy. 6 J If the Jambs of each Window be parallel between themfelves, then, a Right Line, So, bifeding the Angle ISm, &c. perfpedively, will produce the Vanifhing Point of each refpedively, and each Jamb muft, in that Cafe, be divided geome¬ trically, on the Angle, into the feveral divifions required. The Entablature may alfo be proportioned on BK, the fame as on AD, on the other Side ; which will be more accurate, than to depend entirely on the propor— tions being carried around, from the other Side; which, as they diminifh fo much, at the far End, are liable to error. The Angle f at the foot of the Pilafter being obtained, draw f] parallel to the Ground Line, which divide, geometrically, in the Proportion required; that is, fly equal j 4, isthe diftance of the Column, at the Plinth, from the Wall; and i 2, equal 3 4, is the width of the Plinth of the Column ; from all which, draw Lines to V, cuting the inclined Line, in which the Columns ftand, in the per- fpedive proportions of the Columns and Spaces; which may be compleated from the known proportions of the Order, as in former Examples, If r s be taken, geometrically, the width of the Door, &c. in proportion to the Columns and fpaces, Lines drawn to V will give the place of the Door, at the farther End, which may be compleated, by Example 20. The Cieling has nothing of difficulty in it, fave the Ornament, being compofed of Right Lines, regularly difpofed; which, from the geometrical Figure, may eafily be determined. G H, may be confidered and ufed as the Interfedion of the Pidure with the Cieling, on which, the zhvlfiuns are geometrically difpofed; from which, draw Dine® to V; and the feveral divifions, in the length, being found perfpeaively, on GV or HV, Lines drawn to the other Vanifhing Point will cut each Line, drawn to V, in the ratio required; by which, the perfpeaive Figure is formed on the Piaure, . . .■ i n . EXAMPLE XLIII. * Is the Reprefentation of the infde of the Piazza, Covent Garden, from the farther corner of the entrance into the Playhoufe. The Pofition of the Piaure being determined, and confequently, the Inclina¬ tion of the Lines, in which the Piers ftand, is known. Let C be the Center of the Piaure, EV is the Horizontal Line, and V is the Vanifhing Point of one Face of the Piers, found, or determined at pleafure ; the other is out of the Piaure, on the Left, found as ufual ; the Diftance of the Pic- pig, 2 ture is fix Inches and a half, nearly*. Let A B be the Interfeaion of the Piaure, i. e. the Ground Line, and, let S be the determined Seat (on the Piaure) of the corner of the Pier, on the G/ound, Its Diftance from the Pidure being known. Becaufe there is not room, on the Piaure, to fet off its whole Diftance, take CE half the Diftance; and make SD half the diftance of the corner of the Pier; draw DE cuting SC at a, the true place of that Corner, on the Pidure. Draw a V, the indefinite Reprefentation of one Side of the Piers, and aY, to the other Vanifhing Point, whofe Diftance, from G, is nine inches and three fourths, * Let it be obferved, that the Diftance, here ufed, is too little; but, being a true Portrait of fo pub¬ lic a Place, I thought proper to difpenfe with it; by reprefenting it as it appears, from the Station deter¬ mined above. See Preliminary Obfervations, Page u Draw 223