ii4 M. Girard on Navigable Canals 
es ug a certain number of locks whose lifts are res- 
SR Cais &c. we shall have 
LAVAL yA LayHh 3 
And 73 ihe loss of active ars on the whole feng of the 
canal, the sum of tne sepa t 
PL y? PV? Hoe 
which will Ciel in proportion as = number 2 of the 
locks increases. 
ge particular case where all the locks have an equal 
lift gives 
h 
ee 7 ee. rd eee : 
ii which ¢ case the loss of active ite: becomes : 
nh?  h? 
SF 
2 a 
If the total rise of the canal be divided into any other 
number n’ of equal locks, that loss becomes — ; the losses 
o active bigoy in ‘the: two aren ee therefore : - 
= as fgpettsess eee 
seamen are in inverse pace aati? to the number — 
isk Fiape to obtain a gi elg 
Designating by y and y’ the positive expenditure of % wa” 
ter in the two suppositions, we have 
h ut : F 
sa et ; oi efeilas 
=) Sag 
Whence we see that the expenditure ae is so on 
ihe less as the number of locks is greater, | or as their lift is 
smaller. 
‘It becomes exactly proportional to the lift when the as 
cending and the descending boats have the same draft of 
water, the ican supposition which has been tacitly admitted 
hitherto ; for in Sb case we | have: i 
A ; ; 
eee oe ; 
tercont i eciaue tie stipe sss locks of whine 
a oa saa ee ee which is to 
© supplied by the higher levels, the prece 
shows the. great advantages that will result from diminish- 
