Of strange (jlajses. 375

These things being done, I tike ther, differences of the roots, of the great-est to the smallest, for they are from160.0.0. to 415. 6 . 9 . Make choiceof the measure of afoot, according towhich distances we would make ourGlass : let it be A B, which we divideinto thirty parts ; and take twentyparts, namely, two thirds: I adde aline to it at right Angles, namely B,and let it be B C, which 1 divide intofifty five parts. I divide one part intoten, and that one into ten parts more,and those are tens of tens, Let A benul , that is a cyfer , and there placesixty; the second part sixty one: the line joyned to right Angles, will be two ; thethird part sixty two; the line joyned to it will be five: so the twentieth part will beeighty, and the line joyned to the Angle fifty six: to the extremities of these lines Ifasten a pin, and I put a brass Cithern-wire upon them , and upon it I draw a line,and the Parabolical line is exactly described by it; for should we draw it withoutthe help of this cord , it will be wavering, and not perfect. Then take a brass Ta-ble of convenient thickness, and draw the line now found upon it, filing away allthat that shall be above the line C A. These things being done, take an iron rod ofan exact length, namely, twelve foot, as the line D C, and at the end fasted a plate,which shall be for the circumvolution of the axis ; at the other end fasten a spike,that it may be fastned somewhere, and be handsomely turned about. So being wellfixed, we turn it about, by adding claymingled with straw, that it may excellent

well make a hollow place, like to theform of a Parabolical Section; which be-ing dried, we must make another solidone, that it may contain the liquid Me-tal, as the maner is.

Chap. XVII.

A Parabolical SeElion that may burn to infinite difiance.

Z Onaras the Greek, writes in the third Tome of his Histories, That Anaflaftumoved sedition against Vitaliantu a Thracian, and he got those of Mysia , andthe Scythians to stand with him; and in the Country by Constantinople, heplun-deredrhe people, and besieged the City with a Fleet, t JMariannt the Deputy op-posed him; and there being a fight at sea , by an engine made by Paws'* a most ex-cellent man, for he then was famous for Philosophy and Mathcmaticks; for he notonely knew all the secrets of the most eminent Artificer, Archimedes , but hefound out some new inventions himself; the enemies Navy was vanquished. For*Troclm is reported to have made Burning-Glastes of brass, and to have hanged themon the wall against the enemies Ships; and when the Sun beams fell upon them, thatfire brake forth of them like to lightning, and so burnt their Ships and men at sea,as Dion reports that Archimedes did formerly to the Romans besieging Syracuse. ButI will shew you a far more excellent way than the rest , and that no man as ever Iknew writes, and it exceeds the invention of all the Antients, and of our Age al-so;and I think the wit ok man cannot go beyond it.This Glass doth not bum for ten,twenty, a hundred, or a thousand paces, or to a set distance, but at infinite distance:nor doth it kindle in the Cane where the rays meet, but the burning line proceedsfrom the Centre of the Glass of any Longitude, and it burns all it meets with in theway. Moreover, it burns behind, before, and of all sides. Yet I think it an un-worthy act to divulge it to the ignorant common people; yet let it go into the light,