84 PHILOSOPHICAL TRANSACTIONS. [aNNO I673. 



SO quick and effectual, that the blood was stopped in four minutes of time, the 

 calves by their motion making the pledgets to fall off, that had been put on the 

 parts cut, and not a drop of blood appearing. 



The King hereupon caused the quantities that had been thus prepared, which 

 were very considerable, to be immediately dispatched away to his Majesty's fleet ; 

 and it is not doubted, but that upon occasion all that shall happen to be wound- 

 ed will receive great relief and benefit by it. 



Description of the Prosopographic Parallelogram, for delineating Orthographi- 

 cally, by Parallel Visual Rays, the Attitudes and Gestures of the Human Body, 

 observing exactly the Proportion and Symmetry of the Parts. By Mr. John 

 Sinclair. N° 96, p. 6084. Translated from the Latin. 



Let ABCD (fig. 1, pi. 2,) be a prosopographic or delineating parallelogram; 

 HF a central style or pin ; LC a drawing pencil ; R A an index, or oblong ruler, 

 fitted perpendicularly to the plane of the parallelogram, by means of a brass 

 screw nail ; on this ruler are fixed two sights, PR, S V; in the middle of PR 

 is a hole O, and in the middle of S V a thread stretched perpendicular to the 

 ruler, on the middle of which is a small globule, by which, and the hole O, a 

 ray from the object reaches the eye, which in delineating must not be fixed, 

 but free and loose. 



It is to be observed, 1. That a ray passing through the hole O and the glo- 

 bule, will be always perpendicular to the plane of the parallelogram, or its dia- 

 meter, which is a right line passing through the pencil LC, and the fixed centre 

 HF, and the said globule; in which line the globule always is, whatever be the 

 motion of the parallelogram. 2. That Q YXT is the sensible delineatory plane 

 on which the point L of the pencil moves, describing the image by the motion 

 of the ruler AR, into which plane the central style is fixed; and that £<?j3y is 

 the rational or mathematical plane, being a continuation of the former. 3. That 

 all rays will be parallel to each other coming from the object, by the globule and 

 the hole, to the eye, placed according to the direction of the ruler, in as many 

 points of the diaphanous medium, as there are points in the visible surface of 

 the object to be described, which indeed are infinite; as is thus proved: lines 

 parallel to the same line, though not in the same plane, are parallel to each 

 other, by Eucl. xi, 10 ; but all the rays extending from the object, through the 

 sights to the eye, are parallel to the same right line, viz. to the ray passing from 

 the object through the globule and the hole O ; consequently they are parallel 

 to each other. Again, if two right lines be perpendicular to the same plane, 

 those lines will also be parallel, Eucl. xi, 6 ; but the primary ray passing from 

 the object through the sights to the eye, and all the other secondary, are per 



