IQ4 PHILOSOPHICAL TRANSACTIONS. [aNNO 1685. 



a way for raising water, which I conclude to bg new, since it is not used on 

 considerable occasions, where it might be of great advantage. It is as follows: 

 See fig. 5, pi. 5. 



A A is a large glass, made like a tumbler, but much larger, and set upon the 

 chimney board B B — C C is the engine, like a small rock, that constantly spouts 

 out water by the two holes DD: this rock is kept at a distance from the bottom 

 of the glass A A; so that it may plainly be seen that it cannot receive any water 

 by subterraneous tubes. — E E is a factitious coral, reaching from the centre of 

 the rock C C, to the centre of the crown FF. — FF is a crown, bearing on the 

 aperture of the glass A A, and holding the rock C C suspended at a considerable 

 distance from the bottom. — G G a glass, open at both ends, applied to the rock 

 C C, to keep the water on it from falling down. — H H two shells to receive the 

 water from the jets. If the Royal Society will be pleased to appoint some per- 

 sons that may come, and to watch it a whole day, it may be seen whether it 

 will not run constantly, without losing any thing of its strength. I hope that 

 the learned in hydrostatics, being by these means assured of the possibility of 

 such a motion, will be the more ready to think of it, and find perhaps some- 

 thing better than this. But if no person do, I will myself within some months 

 publish this contrivance, with the uses it may be applied to.* 



According to the inventor's desire, the Royal Society ordered that the thing 

 should be observed. Mr. Hook saw it for near half an hour, there being other 

 persons to observe it longer, who watched it about 4 hours together, during 

 which time there sprung out of the rock CC, above 100 times more water, 

 than a vessel of the same size could hold : so that they went away not doubting 

 but the water did circulate in the said engine, and might continue a great deal 

 longer, since it ran still as constantly and as high as at their first coming : and 

 Mr. Boyle, knowing the whole contrivance, assures that it may continue fo 

 a whole day and more; and thinks it worthy to be left for some time to the in- 

 quiry of ingenious men. 



/Accounts of Books. 

 I. ^ Treatise of Algebra, both Historical and Practical. By John Wallis, D. D. 



Professor of Geometry in the University of Oxford, F. R. S. N° 1 73, 



p. 1095. 



This work was published in folio, l685, and is the first book professedly 

 written on the history of the science of algebra. The history however, pro- 

 perly so called, is but a small part of the work, the great mass and bulk of it 

 being made up of the practice of the art, being indeed a complete treatise on 



* The nature of this machine will accordingly be found explained hereafter, viz. in N° 178. 



