322 



Water and its Impurities, with 



sary current, much as # the old fashioned way of having a 

 number of persons eat their soup from the same dish, 

 which prevailed among the earlier settlers of the country, 

 set the contents of the dish in rotation. 1 Or a water 

 wheel driven by steam might answer equally well. The 

 only practical question arising, will be as to the amount 

 of power needed in an engine capable of driving a wheel 

 or pair of wheels dipping into the water in the manner of 

 those of a small steamboat ; such a question is of course 

 easily settled. For the first day or two, perhaps, it only 

 disturbs its surface ; soon the wbole body of water in the 

 lake partakes of the motion, and but little power is needed 

 to keep it moving. If its direction of motion be calculated 

 with reference to the direction of the outlet, an additional 

 current can be added to the latter, a point of no small 

 importance to a city situated as Albany is, with a limited 

 head for supplying the upper portions. 



Another advantage resulting from such motion, is in its 

 preventing so high a temperature as is now found on the 

 surface in summer, from being produced in the water: 

 this, besides many other advantages resulting from it, 

 would to some extent hinder evaporation. 



In this connection it is well to notice one objectionable 

 feature in the methods of leading water now employed. 



The habit is too common in engineers, of carrying it 

 only in closed pipes when it is brought for long distances, 

 and this deprives it of one of the best agencies for keeping 

 it pure. The amount of dead matter which open chanuels 

 would collect in the form of falling leaves and similar 

 refuse, would not affect it any more than it does the water 

 of running streams. 



1 It is related of one large land owner that he was induced to discharge 

 a left handed laborer for the reason that he obtained more than bis pro- 

 portion of bread by dipping against the current which his right hand asso- 

 ciates had established in the dish of bread and milk that' was furnished for 

 supper. 



