larger, equal to, or fmaller, than what it would be, if drawn as it appears upon a plane at the diftance SC or ten inches from the eye. For inftance, the front of the building, fhewn in the drawing, fubftends upon the ruler A B, when viewed by an eye at S, about eighty divifions, or five inches; now, were it required to have the drawing of it eight inches long, then the divifions on ab muft be fuch, as the faid eighty divifions may measure eight inches. Upon the paper on which the defign is intended to be made, draw the line HO to represent the horizon; and through the middle of it draw the vertical line de, croffing the former in h, the center of the picture. Apply the ruler ab upon the line de, fo that its center c. fall upon h, and prick off a fufficient number of divifions upon de. This preparation being made, the procefs for defcribing the objects is as follows:

Mr. Crocker's inftrument, like moft others of the kind, is adapted for finding points only, by the connection of which the bounding lines in the image are formed; but thofe lines themfelves are given by this inftrument, and that in the following eafy manner:

Apply the eye to S, and raifing or depreffing the fupport till the center C appears to fall upon that line in the object, whofe image is required, give the ruler AB the neceffary inclination, till it appears to cover the line by its fiducial edge; and there let the inftrument reft. Then placing the center of the ruler ab upon that divifion in de on the picture, which correfponds with the divifion fhewn by the top of the focket F upon the fupport ED; and giving it the fame inclination with AB (which is eafily done by means of the divided fegment fg) mark upon the picture the extent of the line, as the fame is indicated by the divifions on A B. Thus, fuppofe I wanted to draw the reprefentation of the top of the building fhewn in the figure, looking through SI bring the fiducial edge of A B to cover the line LM; and, letting the inftrument reft, I observe the number on the support to be 37 below O, the inclination 19°, and the apparent extent of the front LM to be from the 53d divifion on the right to the 35th on the left. Then placing the center of the ruler ab upon the 37th divifion above h, and giving it the obferved inclination of 12°. I have the required perfpective appearance of LM

by only drawing a line from the 35th to the 53d divifion of the ruler.

Proceeding in this manner, all the neceflary lines and points in the picture may be found. The breadths of the windows, doors, &c. in buildings, and all other divifions in any object, lying in the fame line, are read off upon A B at one operation of the inftrument, and laid down at one fetting of the ruler ab.

The ufe of vanifhing lines and points, to the artist who is mafter of the true prin ciples of perfpective is great; and to fach an one, the method of fiuding them by this inftrument will be very obvious. Mr. Crocker has, very judiciously, given an inflance of this, in respect to vanisting points which fall in the horizontal line, and which, after the old writers on perfpective, he calls accidental points. In the above inflance, if the line I m be con

tinued till it interfect the horizon in H, that point will be the vanifhing point of all lines, which reprefent horizontal lines in the building; by the affiftance of which moft of the principal lines in the front of the building may be drawn.

It often happens that the principal part of the objects to be reprefented lies upon one fide of the middle point of view; in which cafe it will be found convenient to have the center of the ruler AB opposed to the parts where it will be moft in ufe. For this purpose two holes I and K are made (one on each fide the middle hole G, in the base of the inftrument) to receive the fight-ftaff GS, which may be placed in either of them, as the occafion requires. Thefe holes are exactly at the distance of fifty divifions of the ruler AB, from the middle hole G. When the fight-ftaff :s ufed in either of thefe holes, the divided upright line ed muft not pass through b the center of the picture, as is the cafe when the fight-ftaff is fixed at G; but muft be drawn at the diftance of fifty divifions of the ruler ab, towards the right or left of that center, according as the fupport ED is found upon the right or left of the fight-ftaff.

If you think the above worthy the public's attention, I fhall be glad to fee it in your magazine. I

Gentlemen,

am, Your moft obedient fervant, Jo. PRIESTLEY,

Bradford, Yorkshire, 14 Nov. 1782.

MINUETO

A

NOVEMBER 2.

Covent-Garden.

New comic opera, called the Caftle of Andalufia, written by Mr. O'Keeffe, was performed, the dramatis perfonæ of which

are as follow: Don Scipio, Don Juan, Don Fernando, Don Alphonfo, Ramirez,

Mr. Wilfon. Mr. Fearon. Mr. Mattocks. Mrs. Kennedy. Mr. Reinhold. Mr. Quick. Banditti. Mr. Mahon. Mr. Davies. Mr. Thompson. Mr. Edwin.

Spado,

Sanguino,

Rapino,

Calvette,

Pedrillo,

Phillipo,

Mr. Brett.

Vafquez,

Lopez,

Dame Isabel,

Victoria,

Lorenza,

Catalina,

Mr. Stevens. Mr. Ledger.

Mifs Platt.
Mifs Harper.
Signora Seftini.
Mrs. Wilfon.

Banditti-Servants, &c.

This piece is profeffedly altered from that called the Banditti, in every material paffage, as well as in the name, little more than the firft fcene remaining.

The Caftle of Andalusia contains much bufinefs and intricacy of plot. It opens with the Banditti carousing in a cave, whofe feaft is interrupted with a storm of thunder and lightning, and an account brought of a paffenger, whom they fally forth to attack. This paffenger proves to be the Lord of the Caftle, who is refcued by a Don Fernando, a young gentleman just then coming with the avowed purpose of efpoufing his daughter. But as all this happens in the dark, Pedrillo, the youth's fervant, perfonates his mafter, for the fake of obtaining a reward. In the mean time Spado (Mr. Quick) who is one of the robbers, affumes a different character, croffes through a bye path to the Caftie, and improving thi incident, the knowledge of which he had obtained by listening, gets himself introduced to the house-keeper, Donna Habella, whom he eafily perfuades that the mafter and fervant had changed habits, in order that the former might the better obferve on the qualities of Donna Victoria, whom his father intended to efpoufe without his ever having feen the lady.

Donna Ifabella, with whom her old Lord is in love, refolving the impofition (as the fupe pofes it to be) shall not pafs, communicates the matter to the perfons concerned, at the first interview. A very entertaining equivoque fucceeds, on which the plot chiefly hinges. In the courfe of thef, tranfactions it is difcovered, that the fuppated Victoria (Signora Seftini) is not the daughter of her Juppofed father, but

JOURNAL.

of Ifabella, his love for whom had occafioned him to wish to put this trick upon Don Fernando, who finding the drift of the whole, and being in love with the real Victoria, caufes his fervant Pedrillo to continue the deception, which he does with much humour, till he receives what he fuppofes to be an invitation, but really proves to be a challenge from a Don Alphonfo, (Mrs. Kennedy) who is in love with the daughter of Ifabella.

This, together with the arrival of the young gentleman's father, between, whom and that of Victoria there is a deaf scene, the idea of which is by no means new, leads to an eclairciffement, and the piece concludes with the union of Fernando to the real, and Alphonfo to the false Victoria, all Ifabella's artifices being difcovered by the means of Spado, who, in a humourous fong, promises a future reformation.

Such are the outlines of a piece, which, tho' it may not approach to perfection, was received with applause.

The characters were filled, and dreffed with great propriety.

Signora Settini appeared for the first time on the English ftage, with every advantage of drefs.Her two favorite rondeaus from Il Gsvernante and Il Barone di torre forte, by Giordani, were introduced to English words -She fpoke the dialogue much better than could be expected, and played with her ufual animation and fpirit. Her reception was a moft flattering one, and fuch as from her long refidence amongit us, and her continual efforts to please, fhe is justly deferving of.

Mils Harper fung with great expreffion, and executed two cadences with great taste. Mrs. Kennedy fhould confine herfelf to natural finging, and never attempt a cadenza. The top of her voice is the worst part of it, and in her efforts of the first night she was twice out of tune.

Mr. Quick hit off Spado's archnefs moft admirably.Mr. Edwin fung with his ufual fuccels, and confidering the difficulty of Borgi's Rondeau, in the last act, his articulation was very diftinct.-Mr. Brett had but one fong alfigned him, which he executed with great feeling.-The other performers acquitted themfelves very ably.

The following are fome of the most favourite
SONGS, DUETS, &C.

AIR and CHORUS.
RAMIREZ and BANDITTI.

CHORS.

HERE we Sons of Freedom dwell

In our friendly rock-hewn cell; Pleafure's dictates we obey, Nature points us out the way; Ever great, and ever free, Valour guards our liberty.