C 54 > • 
more- than half an Unit ; wherefore adding I, you have Briggs $ 
Logarithm of 2000, vie. ,3.3010300. 
If any Logarithm be given, fuppofc 3.3010300, throw away 
die Charaderiftic, then over againft thefe Figures 3 ... o.. I ... 
o.-3 - . 0. . o,you have in their refpedive Clafles.1.9952623 1 5’ 
0023 052 3 B 1 * 000069080.. ..o. ..o 
which multiplied continually into one another, the Produd is 
2.000000019966, which by reafon the'Charaderifticis 3, be- 
comes 2000.000019966, &c. that is, 2000, the Natural Num- 
ber defired. I lliall not mention the Method by which this 
Table is fram’d, becaufe you will eafily fee that from the ufe 
of it. 
It is obvious to the intelligent Reader, that thefe Claftes 
of Numbers are no other than fo many Scales of mean Pro- 
portionals: in the firft Clafs, between 1 and io; fo that the 
Jaft Number thereof, -viz;. 1,258925411 is the tenth Root of 
10, and the reft in order afeending are the Powers thereof. 
So in t-he fecond Clafs, the laft Number 1,023192992 is the 
hundredth Root of 10, and the reft in the fame manner are 
Powers thereof. So 1,002305238 in the third Clafs, is the 
tenth Root of the laft of the fecond.and the reft its Powers^rr. 
Or, which is all one, each Number in the preceding Clafs, is 
the tenth Power of the correfponding Number in the next fol- 
lowing Clafs: W hence ’tis plain, that to conftrud thefe Ta- 
bles requires no more than one Extraction of the fifth or fur- 
folid Root for each Clals, the reft of the Work being done by 
the common Rules of Arithmetickj and for extrading the 
fifth Root, you will find more than one very compendious 
Rule in no of thefe Tranf diions , if any one (hall de- 
fire to examin the computus of thefe Tables. 
TheProcefs isexadly the Reverfe of Mr. Briggs's Dodrine, 
in Cap. XII. of his Ariihmctica Lcgarithmica of Flacqs Edition; 
and had Briggs been appriz'd hereof, it would have greatly 
eifed the Labour of deducing the Logarithms of the firlt 
prime Numbers, which appear to have eoft him fo much 
Pains* II. An 
