( 8i ) 
I took the Hint of mine from that of Mr. de 
Leibnitz which put me upon thinking how the 
inward Structure might be contrived : But as it was 
not poiTibie for me to hit upon the original Ideas of 
that Great Man, an exaCt Enquiry into the Nature 
of Arithmetical Operations furniflied me at laft 
with others, which I exprelTed in a rough Model 
of Wood, and fhewed to fome Patrons and Friends, 
who encouraged me to have another made of Brals : 
But the want of an Artificer, able enough to execute 
my Ideas, made me delay it till the Year 1725* ; 
when having fpare Time, and finding an Inclination 
to divert myfelf with Mechanical Operations, I fet 
about it, and finilhed the whole Work, fitted to a 
Reckoning not exceeding feven Places. And in 
\ December of the fame Year, I had the Honour to 
lay this Machine before my Sovereign, the prefent 
Landgrave of Hejfen c Darmftadt^ and the Hereditary 
Prince his Son, to whom I demonftrated the Me- 
chanifm of the whole Invention. 
I own that the gracious Reception it met with 
from both their HighnelTes, as well as the exprefs 
Recommendation of Mr. de Wieger , one of the 
Prince’s Privy-Council, would have been powerful 
Inducements for me to have publifh’d at that time an 
Account of my Machine ; but I was checked by 
the Uncertainty I was under, whether poflibly 
Mr. Leibnitz ? s Machine had not been brought to its 
Perfection ; in which cafe there is no doubt but the 
Operation of his Machine, if it would really per- 
form what is promifed in the Defcription, would 
have been eafier than mine, and confequenrly pre- 
ferable to it, provided its Structure did not prove 
L z too 
