[ S°9 ] 
TheTheorems, orRules, for theCafes ofCbmpound 
Intereft, without their inveftigations, were inferted 
by Mr. Jones, in the quarto edition of Logarithms, 
publifhed by Gardiner ; and the Rules were alfo com- 
municated to Mr. Dodfon, who published them, by 
Mr. Jones’s leave, with examples to ilkiftrate the 
ufe of his Antilogarithmic Tables: But the invefti- 
gations of thefe Theorems not having yet been made 
public, it is apprehended that Gentlemen curious 
in thefe (peculations would be pleafed to fee them : 
And fhould the following Effay be approved of by 
you, who have been for many years acquainted with 
the Finances of this Nation, and the importance of a 
ready knowledge in computing the Intereft on the 
National Loans, you will be pleafed to communicate 
it to the Royal Society. 
I am, SIR, 
Your moft humble fervant, 
John Robertfon. 
In this fubjedt five particulars are taken into con- 
fideration. 
ift, The Annuity, Rent, or Penfion. 
2d, The Times that Annuity, Rent, or Penfion 
is to continue. 
3d, The Rate of Intereft ufed in the computation. 
4th, The Amount of thofe Rents, and their In- 
tereft, when they are forborn to be received any 
times after they are due. 
5th, The prefent worth of thofe Rents, fome times 
before they are due; or, of a Sum to be re- 
ceived before it is due, Difcount being allowed. 
