Electrical news and engineering . s the disposalof excavated material. (c) The unknown water hazard and the impossibility ofpredicting the cost of unwatcring within reasonable limitsof accuracy. (d) The ditTiculty and hazard attending the driving of,and maintaining a pressure tunnel of unprecedently largediameter in the clay formation of the Whirlpool Ravine. (e) The difficulty in connection with the construction ofa distributing chamber in the shale and sandstone at Queen-ston. As against the above, the ditficuUies and hazards in the caseof the open canal were limited to two main points; firs
Electrical news and engineering . s the disposalof excavated material. (c) The unknown water hazard and the impossibility ofpredicting the cost of unwatcring within reasonable limitsof accuracy. (d) The ditTiculty and hazard attending the driving of,and maintaining a pressure tunnel of unprecedently largediameter in the clay formation of the Whirlpool Ravine. (e) The difficulty in connection with the construction ofa distributing chamber in the shale and sandstone at Queen-ston. As against the above, the ditficuUies and hazards in the caseof the open canal were limited to two main points; first, theremoval of the earth overburden in the canal prism, and sec-ond, the permanent holding of the slopes subsequent to suchremoval. While it may never be possible to establish finallythe comparative importance of the above points on the basisof actual construction, the fact remains that the work on theopen canal has demonstrated beyond doubt that the jiver-burden can be removed with no more difficulty fjjan was an culty than wa. Chippawa, 1902-16 ticipated and that the means orginally devised will hold thebanks safely within the limits of the predetermined slopes. Hydraulic Comparison In the matter of purely hydraulic comparisons, the firstpoint to consider is that both types of waterway would, ofnecessity, have the same point of intake at Chippawa and thesame point of discharge at Queenston, so that they are ex-actly on a par as regards the utilization of available grosshead, neither having any primary advantage over the otherin this regard. Since 1902 the water level at Chippawa has been observ-ed and recorded twice daily. Fig. 1 shows the mean dailyelevations for the ensuing period compiled in the form of aduration curve. The following facts are deducible from thiscurve. (a) The mean level for the entire period is about ele-vation (b) A level of elevation or higher is obtained fornearly 99 per cent, of the entire period. (c) A level of elevation 561 or higher
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Keywords: ., bo, bookcentury1800, bookdecade1890, bookidelectricalnewsen31donm
