147 . Rockets may Aquatic others ; so that when she sails out, she will be between on floats: then in the places where their eyes should be, Oplical t'ireworks the other ships : you must not let this ship advance till bore holes two inches deep, inclining downwards, and Imitations the guns at her ports take fire. wide enough to receive a small portfire ; the portfire of fireTo fire sky. 7, fire sky-rockets under water, you must have stands cases for this purpose must be made of brass, two inches 1ockets un made as usual, only the rails must be placed flat instead long, and filled with a slow bright charge. In the midder water. of edge wise, and have holes in them for the rocket dle of one of these cases make a little hole ; then put sticks to go through ; for if they were hung upon hooks, the portfire in the eye-hole of the swan, leaving about ket; to do which, bore a bole between them in the top Neptune, a sivan, a water-wheel, or any thing else you which carry a leader: if the swan is filled with rockets, 148 choose. they must be fired by a pipe from the end of the waterNeptune in To represent Neptune in his chariot, you must have a rocket under the tail. When you set the swan a swimbis chariot. Neptune (made of wood, or basket work) as big as life, ming, light the two eyes. 150 fixed on a float large enough to bear his weight; on To make a fire-fountain for the water, first have a Water fire which must be two horses heads and necks, so as to seem float made of wood, three feet diameter; then in the fountains., Fig. 7a. swimming, as shown by fig. 70. For the wheels of the middle fix a round perpendicular post, four feet higli, gray charge, and third, place eight more of these cases, in the same manthe rest with portfire composition. ner as before, and on the top of the post fix a gerbe ; If Neptune is to give fire to any building on the wa then clothe all the cases with leaders, so that both they ter ; at his first setting out, the wheels of the chariot, and the gerbe may take fire at the same time. Before and that on his head, with the white flames on the firing this work, try it in the water to see whether the horses heads, and the portfires in their eyes and nostrils, float is properly made, so as to keep the fountain upmust all be lighted at once; then from the bottom of right. the white flames carry a leader to the trident. As Nep As the artificial fire-works which we have described, Opticalini 151 tune is to advance by the help of a block and cord, you require considerable caution in their preparation and ma- tations of must manage it so as not to let him turn about, till the nagement, and are attended with great expence, at- fire-worke brilliant fires on the horses and the trident begin; for tempts have been made to imitate some of the more it is by the fire from the horses (which plays almost up- simple kinds by optical delusion, and to give to the obright) that the building, or work, is lighted; which jects represented the appearance of moving fire, though must be thus prepared. From the mouth of the case they be really fixed, and no fire be employed. These which is to be first fired, hang some loose quick-match attempts have been tolerably successful; and by means to receive the fire from the horses. When Neptune is of this invention, a spectacle of artificial fire-works may only to be shown by himself, without setting fire to any be apparently exhibited at a trifling expence; and if the other works, let the white flames on the horses be very pieces employed are constructed with ingenuity, and short, and not to last longer than one case of each wheel, with a proper attention to the rules of perspective, while and let two cases of each wheel burn at a time. in viewing them we employ glasses which magnify the 149 Swans and If you would have swans or ducks discharge roc- objects, and prevent them from being too distinctly seen, ducks in kets into the water, they must be made hollow, and of a very agreeable illusion will be produced. paper, and filled with small water rockets, with some The artificial fire-works imitated with most success paper water. 4 C of firewords Fig. 71. Optical paper blackened on both sides, and very opaque ; and from the circumference, decreasing in breadth to a cer- Oprical Invitations having delineated on a piece of white paper the figure tain distance from the centre, fig. 74.: cut the remain. Imtatik of Fire- of a gerbe of bre, apply it to the black paper, and with der of the circle into spirals of the same kind, open works the point of a very sharp penknife make several slashes and close alternately; then cement the paper circle to (Piate CCCCLVII. fig. 71.) in it, as 3, 5, or 7, pro a small iron hoop, supported by two pieces of iron, ceeding from the origin of the gerbe : these lines must crossing each other in its centre, and adjust the whole not be continued, but cut through at unequal intervals. to a small machine, which will suffer it to revolve round Pierce these intervals with unequal boles made with a its centre. If this moveable paper circle, cut in this pinking iron, in order to represent the sparks of such a manner, be placed before the representation of your sun, gerbe. In short, you must endeavour to paint, by these with a light behind it, as soon as it is made to move to lines and holes, the well known effect of the fire of in wards that side to which the convexity of the spirals is flamud gunpowder, when it issues through a small aper turned, the luminous spirals, or those wbich afford a pasture. sage to the light, will give, on the image of the radii According to the same principles, you may delineate or jets of fire of your sun, the appearance of fire in conthe cascades (fig. 72.) and jets of fire which you are de tinual motion, as if undulating from the centre to the sirous of introducing into this exhibition, which is pure circumference. ly oprical; and those jets of fire which proceed from The appearance of motion may be given to columns, the radii of suns, either fixed or moveable. It may ea pyramids, and globes, cut through in the manner abore sily be conceives, that in this operation taste must be described, by moving in a vertical direction a bard of the guide. paper cut through into apertures, inclined at an angle If you are desirous of representing globes, pyramids, rather different from that of the spirals. By these means or revolving columns, draw the outlines of them on pa the spectators will suppose that they see fire continually per, and then cut them out in a helical form; that is, circulating and ascending along the spirals; and thus cut out spirals with the point of a penknife, and of a will be produced an optical illusion, in consequence of size proportioned to that of the piece. which the columns or pyramids will seem to revolve. It is to be observed also, that as these different pieces We have thus briefly explained the principle on which have dilerent colours, they may be easily imitated by artificial fire-works may be imitated; and as the taste of pasting on the back of the paper, cut as here described, the artist may suggest io bim many circumstances which very fine silk paper coloured in the proper manner. As may improve the representation, and render the illusion jets, for example, when loaded with Chinese fire, give stronger, we shall not enlarge further on the subject, à reddish light, you must paste to the back of these jets but shall conclude this article with a few observations transparent paper, slightly tinged with red; and pro on illuminated prints and drawings, which are someceed in the same manner in regard to the other colours times introduced as accompaniments in these imitations by which the dierent fire-works are distinguished. of artificial fire-works. When these preparations have been made, the next The mode of preparing these illuminations is thus dething is to give motion, or the appearance of motion, to scribed in Huttun's translation of Montucla's Recreathis fire, which may be done two ways, according to tions. Take some prints representing a castle, or palace, circumstances. &c.; and having coloured them properly, cerent paper li a jet of fire, for example, is to be represented, to the back of them, in such a manner that they shall prick unequal bules, and at unequal distances from each be only semitransparent; then, with pinking irous of other, in a band of paper, fig. 73. and then move this diferent sizes, prick small holes in the places and on band, making it ascend between a light and the above the lines where the lamps are generally placed, as along jet; the rays of light which escape through the holes of the sides of the windows, on the cornices or baluthe nioveable paper will exhibit the appearance of sparks strades, &c. But care must be taken to make these rising into the air. It is to be observed that one part of holes smaller and closer, according to the perspective the paper must be whole; that another must be pierced diminution of the figure. With other irons of a larger with holes thinly scattered; that in another place they size, cut out, in other places, some stronger lights, so must be very close, and then moderately so : by these as to represent fire-pots, &c. Cut out also the panes in means it will represent those sudden jets of fire observ some of the windows, and cement to the back of them ed in fire-works. transparent paper of a green or red colour, to represent To represent a cascade, the paper pierced with holes, curtains drawn before them, and concealing an illumiinstead of moving upwards, must be made to descend. nated apartment. This motion may be easily produced by means of two When the print is cut in this manner, place it in the rollers, on one of which the paper is rolled up, while it front of a sort of small theatre, strongly illuminated is unrolled from the other. from the back part, and look at it through a convex Suns are attended with some more difficulty ; because glass of a pretty long focus, like that used in those small in these it is necessary to represent fire, proceeding from machines called optical boxes. If the rules of perspec; the centre to the circumference. The artifice for this tive have been properly observed in the prints, and if purpose is as follows. the lights and shades have been distributed with taste, On strong paper describe a circle, equal in diameter this spectacle will be highly agreeable. to the sm which you are desirous to exhibit, or even Before dismissing this subject, it may not be improper Manage somewhat larger ; then trace out on this circle two spi- to point out the most effectual means of relieving those ment of rals, at the distance of a line or half a line from each burns, to which fire-workers are so nuch exposed . Home orang other, and open the interval between them with a pen When the burn is first received, and before blisters fire-worki knife, in such a manner, that the paper may be cut arise, the best applications are oil of turpentine, strong + spirits, ter must be let out, and the sore covered with rags, Alanage. ige. spirits, rectified spirit of wine, or camphorated spirit, of with which linen rags must be wetted and kept moist on the part till the pain abates. If no other remedy can be procured, immersing the part for a long time in cold water will often afford great relief. When these means have been neglected, and blisters arise, if these are is small, they should not be opened; but if large, the wa ment of Burns. ance. * An. ante P Y R Ρ Υ Τ PYROTICS, in Medicine, caustics, or remedies PYRRHUS, the name of two kings of Epirus. See Pyrrhus either actually or potentially hot; and which accord EPIRUS. 11 ingly will burn the flesh, and raise an eschar. See Cau PYRUS, the PEAR-TREE. See BOTANY Indez ; Pythagoras STICITY. and for the culture of this fruit, see GARDENING. For PYRRHICA, in antiquity, a kind of exercise on an account of the processes followed in making periy, horseback, or a feigned combat, for the exercise of the see AGRICULTURE. cavalry. PYTHAGORAS, a celebrated philosopher of anIt was thus called from its inventor Pyrrhichus, or tiquity, respecting the time and place of wbose birth Pyrrhus of Cydonia, wbo furst taught the Cretans to the learned are much divided. Eratosthenes asserts, march in measure and cadence to battle, and to ob that in the 48th Olympiad *, when he was very youn, serve the pace of the Pyrrhic foot.-Others derive he was a victor at the Olympic games. Hence wr Cir. 588. the name from Pyrrhus the son of Achilles, who insti- Bentley + determines the date of bis birth to be the 4th + Dissert. twted this exercise at the obsequies of his father. year of the 43d Olympiad; whilst Lloss I, who denies in the Ep. Aristotle says, that it was Achilles himself wbo invent that the Olympic victor was the same person with the ; is Phalaed it. philo-opher places it about the 3d year of the 48th 0.1 Chron. of The Romans also called it ludus Trojanus, “ the lympiad. Mr Dodwell § differs from both, and wishes PythugoTrojan game;" and Aulus Gellius decursus.-It is to fix the birth of Pythagoras in the 4th year of the » Two Dis. doubtless this exercise that we see represented on me 520 Olympiad. Of the arguments of these learned wri. s rtations dals by twn cavaliers in front running with lances, and ters, Le Clerc has given a summary in the Billioileaque on the age the word decursio in the exergum. Choisée, tom. x. p. 81. &c. and from a review of the of l'ha crePYRRIIICHIUS, in the Greek and Latin poetry, whole, it would appear that he was not born earlier than and Py thagorus. a foot consisting of two syllables, both short ;—as, the 4th year of the 434 Olympiad, or later than the Deus.-Among the ancients this foot is also called pe- 4th year of the 52d; but in what particular year of riambus; by others hegemona. that period his birth took place, cannot with any degree PYRRHO, a Greek philosopher, born at Elis in of certainty be ascertained. It is generally believed Peloponnesus, flourished about 300 B. C. He was the that he was born in the island of Samos, and that he disciple of Anaxarchus, whom he accompanied as far Nourished about 500 years before Christ, in the time of * Tusc. as India, where be conversed with the Brachmans and Tarquin the last king of Rome *. His father Vne Guest. Gymnosophists. He had made painting bis profession sarchus, who is thought by some to have been a lapida-ib. iv. before he devoted bimself to the study of philosophy. ry, and by others a merchant of Tyre, appears to have cap. I. He established a sect whose fundamental principle was, been a man of sonie distinction, and to bave bestowed That there is nothing true or false, right or wrong, upon his son the best eduction. honest or dishonest, just or unjust; or that there is no Jamblicust relates a number of wonderful stories re. t Fit Pystandard of any thing beyond law or custom, and that specting Pythagoras's descent from Jupiter, his birth, tu. 5. n. uncertainty and doubt belong to every thing. From and early life; and represents him even in his youth as this continua! seeking after truth and never finding it, a prodigy of wisdom and manly seriousness. But mot the sect obtained the name of Sceptics or Pyrrhonians, of these idle tales confute themselves, afford nothing of from the founder, who is said to have acted upon bis importance to be depended upon, and only prove the own principles, and to have carried his scepticism to credulity, carelessness, and prejudice of their author. such a ridiculous extreme, that his friends were obliged Of bis childhood and early education we know nothing, to accompany bim wherever he went, that he might not except tbat he was first instructed in his own country be run over by carriages, or fall down precipices. If by Creophilus, and afterwards in Scyrus by Pher evdes this was true, it was not without reason that he was (see PHERECYDES). According to the custom of the ranked among those whose intellects were disturbed by times he was made acquainted with poetry and music; intense study. But it is treated by a modern writer eloquence and astronomy became his private studies, as a mere calumny invented by the dogmatists; and we and in gymnastic exercises he often bore the palm for are strongly inclined to be of his opinion, (see ScEp. strength and dexterity. He first distinguished himself TICS). Pyrrho died about the goth year of his age, in Greece at the Olympic games, where, beside gaining when his memory was honoured with a statue at A. the prize, he is said to bave excited the highest admithens, and a monument erected to him in bis own ration by the elegance and dignity of his person, and country. the brilliancy of his understanding. Soon |