186 -ASTRONOMIC AL, &c. 
,.g. Another and very expeditious way is:as follows : 
' Multiply the adventure by 100 ; and divide the product by 
100 lefs the rate of infurance, (or, the difference between 100 
and the rate of infurance) and the quotient will thew the fum 
to be infured. 
Example, Adventure, £.315. Rate of infurance 30 per 
cent. 
4300 gis 
jo 100 
- 70 ) 31500 ( 450 
zgo.‘ 
0350 
339 
0009 
