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LETTER X. 
THAT during your refidence at the 
Charter Houfe, you have forgotten 
all you knew of Arithmetic before your ad* 
mition, is no great wonder; nor is it any 
great misfortune. Arithmetic, (derived, you 
know, from afipog and pirgov) is a Science 
which fchool boys learn only as a mechani- 
cal art : they are taught, by certain iles, to 
pile up numbers and pull them down again, 
as, by way of amufement, they would the 
men of a Backgammon-table, without the 
leafl comprehenfion of the reafon for the 
rule, the powers of the numbers with which 
they work, or the nature of the operation. 
But when Arithmetic is firft propofed, as a 
new Science, to a young man capable of 
reflexion, he contemplates its appearance 
with the fame inquifitive eye, the fame cu-r 
riofity, the fame defire of information, that 
he would behold a ftranger pofTefling powers 
that could reach to the very gates of infinity. 
Such a Student will probably reafon thus. 
" Here are ten fymbolical characters, i, 2, 
3> 4> 5> 6, 7, 8, 9, o; with which, when I 
am 
