!>() HALIFAX \vAri;i: works.- jounston. 



The main dam at Si>ruce Hill Lake is au earthen structure 

 1,200 fwt Ifoio-, 12 feet wide on top tlie slopes, hoth iniu^r and 

 outer, beinii' huilt of iiranite alxtut 1(1 inclics thick. There is 

 no puddle or core-w;ill throiiiih it, h\il it was hnilt by simply 

 compactiiiii' layers of the best available material. There are two 

 snuiller dams about -'jOO feet and 250 feet long respectively, of 

 the same se<*tion as tlu' main dam. The dams were constructed 

 in 1S()8 and the granite face wall in front of the dam was 

 built in lSl)l-3 and the dams raised at that time. The present 

 waste-weir was bnilt in 1888 at an elevatio'a of ;>02.70. It is 

 constructed of granite witli four openiings of 9 feet 3 inches 

 each in the clear, separated l)y cast-iron standards to receive 

 stop logs to retain the surplus water. There are three such 

 timbers in place, each (5 inches sipiai'c, thus raising the level to 

 364.20. 



Gnic'Huiises. 



There are two gatediouses at Chain Lakes. The north (me, 

 originally bnilt in 1857, is locat<'d at the north part <d' the <lam 

 at the toe of the outer slope, and consists of an iri»n tank l)uilt in 

 sections, l)olted together and caulked. The water is drawn 

 from the lake to this cluunber by a 24:-inch i)ii)e. It was raised 

 in 1894 by bolting a section to the existing chamber. The 24- 

 inch supply nmin is connected with this house. 



The south gatediouse was built in 1894, over tlie channel 

 which led to tlic old south pi]>e house, which was tlu' original 

 one built in ls4s and dcsti'oycil when the new one was com- 

 pleted. The new one is built of concrete and is l(i feet deep by 

 124- feet wide by lOi feet long with walls 4 feet thick. It is 

 drainccl by a 12-incli pipe iioth the 24-inch and ihe 2T-inch 

 niai'nis connect in this house, but may lu' scjiarated should 

 occasion arise. There is a straining wall about 100 feet long in 

 front of this gate-house built of loose stones, 4 feet 6 inches 

 thick <in tdp with slopes of 1 to 4. I'he new house is ample in 

 size and avoids the difficulty always had with the north house 

 which is too small to vent the water tVeelv, and was alwavs in 



