HALIFAX WATER WORKS. JOHNSTON. 97 



danger of choking up owing to the small size of the screen 

 chambers. There is a weir near the north gate-house to measure 

 the water let down by the 12-inch pipe to the mill owners. 



The original Spruce Hill Lake gate-house was of similar 

 desig'n to the old ones at Chain Lake, consisting of an iron 

 tank with three divisions, an inlet, screen and outlet chamber, 

 and was built about 150 feet north of this dam,, a 20-foot pipe 

 running through the dam and connecting with the lake. In 1889 

 a permanent structure of brick, concrete and granite was built 

 in the dam of the following dimensions : 16 feet deep by 10 

 feet 4 inches wide >and 8 feet 5 inches long, with walls 4 feet 

 thick. 



The scree/ae ?re made of ISTo. 19 brass wire, and have sixty- 

 four meshes to the square inch. 



Employees of the water department live both at Spruce Hill 

 Lake and at Chain Lake dams, whose duty it is to look after 

 the dams and gate-houses. The screens, in summer when the 

 water is low, require changing frequently as they become choked 

 with leaves or other impurities suspended in the water. Dur- 

 ing the fall of 1905, when the water was at its. lowest, two men 

 were on duty day and night continually changing the screens, 

 otherwise the supply could not have been kept up to the city 

 through them. 



Canal. 



As has already been stated, the water was conduct el from 

 Long Lake to Chain Lakes by a canal, which was originally 

 constructed in. 1848 by an open cut, and was intended to be 

 low enough to draw the water of Long Lake down seven feet 

 below the waste- weir level, but during construction, owing 'to 

 difficulties met with by the contractor, the grade line was raised 

 1 foot 3 inches, thus, only allowing 5 feet 9 inches of Long 

 Lake water to be drawn off. The conduit was 2 feet by 2J feet, 

 and was entirely too small to pass the water in sufficient volume 

 to give full effect to the storage of Long Lake. The present 



PROC. & TRANS. N. S. INST. Fci., VOL. XII. TRANS. 7. 



