CO129-204 - Acting Governor Marsh - 1882 [11-12] — Page 378

373

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that its floor will be at a level of 12 inches below that of the former - Along the floor of the Subway

will be laid the 18 inch delivery pope

which forms the continuation of the vertical Sluice main. The

terminate.

er

the

Drawing

masonry of the Culvert will

lasın shown in No 5. and the water will be passed over a

gauge Gun metal war

weer with a knife edge and graduated sides for the purposes of measuring the Volume: passed into the tunnel the inlet mouth of which is also in the

men.

the

gange

basin.

28. The lye wash. The bye wash of the

reservoir has already been formed by nature

shape of a small and narrow running parallel to the Fytam gorge as

shown in Drawing

N1. The bottom.

w valley

of

this

Valley is about seven feet below the top of the proposed masonry dam and its

average width is about 150 feet or more than four times the actual width required for the overflow during the severest preskets - As this width actually exists and notwithstanding that- it is so

greatly

in excess of actual, require ments it is not intended to incur the

may

and

expense of contacting it in,

any way, the bye wash works therefore be limited to the formation of a Granite ashlar overflow- weir across the small valley flanked by two solidly beult lateral divarf walls to confine the overflow within bounds.

As the trial excavations already made on the spot have revealed the presence of rock

along the entire floor of the byerwick it will not be necessary to pave the latter. The minor

12.