130 ARITHMETIC. 



EXAMPLES. , " 



J. If lolb.at Boston make plb. at Amsterdam ; polb. at 

 Amsterdam^ iislb. at Thoulouse j how many pounds at 

 Thoulotise are equal to 5olb. at Boston ? 



Ant. Cons. 

 10 : 9 



■90 : 112 



112 :: I s6 



^6 the answer, 

 2. If 20 braces at Leghorn be equal to 10 vares at Lis- 

 bon ; 40 vares at Lisbon to 80 braces at Lucca j how ma- 

 ny braces at Lucca are equal to 100 braces at Leghorn ? 



Ans. 100 braces, 

 CASE It. 

 W7:en it is required to fitid hoiv many of t,he first hind of coift, 

 ^weighty or measure^ nienticned in the question^ are equal to a 

 given number of the last. 



RULE. 



Proceed as in the first case, only make the product of 

 the consequents the first term, and that of the antecedents, 

 the second. 



EXAMPLES. 



* In performing this example, the first abbreviation is obtained 

 by dividing 90 and 9 by their common measure 9 ; the second by 

 dividing 10 and 50 by their common measure 10 ; the third by 

 dividing 10 and 5 by their common measure 5 ; and the fourth, 

 or answer, by dividing 2 and ;i2 by their common measure 2. 



