[ '34-] 



(Plate II. Fig. 3 ) beyond the fides of the pages, and each is 

 numbered in fucceflion from one to feven, and they are fo placed 

 below one another as to permit the numbers on all of them to 

 be feen at once, as in Plate I. 



When any number of thoufands is pointed out it can by 

 means of thefe rulers be immediately fele(5led ; the feries of 

 feven pages, which one of thefe rulers opens, is cut like the 

 alphabet of a ledger at the edge, in feven divifions. By thefe 

 means the page containing the hundred which is wanted is in- 

 ftantly found. In the page thus found the tens from ten to 

 feventy inclufivc are divided from each other, fo as to be in- 

 ftantly diftinguifhable, and the units under each divifion are 

 in like manner eafily fele<5ted. 



Plate III. is a fpecimen of the firfl page of the vocabulary, 

 and though it is but one-fifth of the real fize it is fufiiciently 

 diftindl. It is divided into eight clafTes ; all the claffes are 

 numbered downwards feriatim from i to 77, omitting cyphers 

 or zero and eights and nines. When once the clafs required 

 is afcertained any number on the page can be found immedi- 

 ately: — As for inftance, the reader will eafily feledl Clafs IV. 

 Number 36, or Clafs VII. Number 77, and fo of the reft. 



Nothing remains to be explained but the manner in which 

 the clafs in each page is pointed out by the machinery. For 



this 



