. WITH NOTES. 453 



tifie 6 it, with feveral others. They 

 all faw, that no fooner thefe great 

 Weights paffed the Diameter-line 

 of the lower 7 fide, but they hung a 

 foot further from the Centre, nor 

 no fooner paifed the Diameter-line 

 of the upper 8 fide, but they hung a 

 foot nearer. Be pleafed to judge 

 the confequence. 



6 testify for justify. P. 7 upper for lower. MS. and P. 



8 lower for upper. MS. and P. 



[An advantageous change of Centres. ] This is the 

 most minutely as well as circumstantially noted of all 

 the Marquis s inventions ; yet we have no evidence of 

 his ever afterwards recurring to it. The mention of Sir 

 William Balfour makes it probable that the exhibition 

 of this great weighted wheel took place between 1638 

 and 1641. [See Life, Times, &c., page 25.] Dr. John 

 Dee, in his celebrated preface to Sir Henry Billingsley s 

 first English edition of Euclid, published in folio, 1570, 

 speaks of such a machine, as not only possible, but as 

 having been actually constructed, and &quot; a thing most 

 incredible if not seen ;&quot; this, compared with the lan 

 guage used by the Marquis, would lead to the supposition 

 that he had not only read but copied the passage. 



It is difficult to reconcile the statement he has here 

 made, with the declaration on the title page, of his 

 inventions having been &quot; tried and perfected.&quot; In this 

 single instance, he leaves the reader to &quot; Be pleased to 

 judge the consequence.&quot; 



Dr. Desaguliers, in a memoir, published by the Eoyal 

 Society, vol. 31, 1720-21, quoting the foregoing article, 

 ventures the reply : &quot; Now the consequence of this, 

 and such like machines [assuming them to be as above 



