Bowles, Carington [Hrsg.]: All Draughtsmen's Assistant, Or, Drawing Made Easy: Wherein The Principles Of That Art Are Rendered Familiar In Ten Instructive Lessons ... Explain'd by a great Variety of Examples from the most approved Designs, on Copper-plates, neatly engraved: With a suitable Introduction on the Utility of this Noble Art ; And Observations on Design, as well in regard to Theory as Practise (London, [ca. 1777])

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To execute a Direct Vievv. See FJar. I. Plate V.

If you would draw a Direct View of a Houfe and Wall, or, in other Words, a
Geometrical Elevation to be raifed from a Plan or Ground-plot, by a Scale, mad*
according to the Dimenfions of the Building, fir ft rule the Bafe Line A A above the
Plan B B at any He-ght you pleafe. Then erect Perpendiculars at C and D for the
Extremities of the Houfe, alfo fiom the Windows ma-rked in the Plan e f, g h, i kT
Im, n <?, which will give the Breadth of all the Windows. Rule thefe Perpendiculars
faintly with Black Lead. Having done this, fuppofe the Bottom of the Parlour or
Ground-Floor Windows to be 3 Feet above the Bafe Line A A, take off" with your
Compaffcs 3 Feet from the Scale, and transfer that Meafure from p to q at each End
of the Houfe. Then fuppofing the Parlour Windows to be 5I Feet high, fet of? that
Meafure from the Scale, and transfer it to the Extremities from q to r. Then, if
the Diftance from the Top of the Parlour Windows to the Bottom of thofe on the
Firft Floor be 5 Feet, take it as before from the Scale, and fet it off" at each End
from r to s. Then fuppofe the Chamber Windows to be 54 Feet high, transfer that
Diftance from the Scale from s to t, at each End.. Next, fuppofing from the Top
of the Firft Floor or Chamber Windows to the Bottom of the Cornice to be 3 Feet,,
take 3 Feet from the Scale as before, and fet off" that Diftance at each End from
/ to u. Then if the Cornice be 1^ Foot high, meafure it off" from the Scale, and
transfer it to each End from u to w. Laftly, fuppofe the Roof to be 3 Feet from the
Top of the Cornice, fet off" 3 Feet at each End from w to x, then rule faintly with
your Pencil the Parallels q q, r r, s s, t r, u w w, x x, and you have the Height
and Breadth of all the Windows, &c. which having outlined, rub out the Parallels-
and Perpendiculars with Bread ; and fetting off" 6 Feet, the fuppofed Height of the
Wall, rule the Line from A to Y at each End, and the Work is ready for fhadinir.

To draw an Oblique View.. See Fig. II. Plate V..

Firft rule the Horizontal Line D E, and if the moft remarkable Object he on the.
Left-Hand, as at C, having taken your Station on the Bafe Line as at G, from that
Place raife a Perpendicular G I, which at the Point of Sight K will interfect the.
Korizon ; and to find the Roof and Bafe of the principal Building C, rule the Dia-
gonals L K and M K.

N. B. Obferve whether the Profpect before you make a Curve, which if it fhould,,
be careful to make the fame in your Copy, whether it be direct or oblique.

To draw a View wherein are Accidental Points. See Fig. Ill: Plate V,.

Suppofe a large Building in which are feen two Fronts taking different Directions*.,
as in this View : fix your Station at A about the Center of the Bafe Line, afcer which
rule the Horizontal Line B G, then fix. upon that your Points of Sight D and E ;
and rule firft the Diagonals E H and E I, and you may draw Diagonals from the
Point of Sight D to F, G, and K, &c. that they may take their proper Directions-
towards their refpective Points of Sight.

Accidental Points feldom intervene where there is but a fmall Diftance, as in Canals,.
Groves, Noblemens Seats, &c. which are to be drawn by the ftricteft Rules of Per-

fpectiveo.'