IQO I'HILOSOPHICAL TRANS ACTI 0\S. [aNNO 1727- 



for without being able to observe, compare, and calculate the exact quantity of 

 weight, force, velocity, motion, or any other change to be observed in making 

 experiments, effects may be attributed to causes which are not adequate to 

 them, and sometimes expected to be produced even without a cause; as appears 

 by the cost and trouble of those who have attempted to find the perpetual mo- 

 tion. Though such persons may make some discoveries, their philosophy will 

 be at best but conjectural, and their conclusions only guess work. The mere 

 mathematician, on the other hand, wants postulata in physics ; or taking things 

 for granted on the report of others, comes often to wrong conclusions, though 

 he reasons justly ; because hi< premises are false. Men of warm imaginations, 

 who wanted mechanics or mathematics, or would not apply them to physics, 

 have pestered the learned world with philosophical romances, such as the 

 Cartesian system, contrived for the diversion of the lazy and talkative. 



But the incomparable Sir Isaac Newton has not only shortened the geometri- 

 cian's work, by his wonderful discoveries in abstract mathematics ; but has also 

 taught us, by his own practice, how to make and judge of experiments and ob- 

 servations, with the utmost accuracy : and as he avoided making hypotheses, 

 he was so cautious as to deliver only by way of queries, several truths which he 

 was convinced of; because he wanted a sufficient number of experiments to 

 make them as evident as those others, by which he has so far improved and 

 advanced natural knowledge. Our author has followed his steps, asserting no- 

 thing but what is evidently deduced from those experiments, which he has care- 

 fully made, and faithfully related ; giving an exact account of the weights, 

 measures, powers and velocities, and other circumstances of the things he ob- 

 served ; with so plain a description of his apparatus, and manner of making 

 every experiment and observation, that as iiis consequences are justly and easily 

 drawn, so his premises or facts may be judged of by any one that will be at 

 the pains to make the experiments, which are most of them very easy and 

 simple. 



His account of every thing is written in such an intelligible manner, that the 

 inquisitive reader is capable of understanding it, without being puzzled with 

 perplexed calculations and complex experiments; which authors have sometimes 

 contrived, in order to be admired for those things, which they themselves 

 found out either by mere chance, or with very little labour. He has illustrated, 

 and put past all doubt, several truths mentioned in Sir Isaac Newton's queries; 

 which though believed by some of our eminent philosophers, were called in 



of utility also. He seems indeed to have been less desirous of exciting admiration for the talents 

 which he possessed, than of meriting gratitude for the manner in which he employed them. 



