ELECTRIC POWER FOR CITY TRAMS.

Otago Daily Times, Issue 11796, 27 July 1900, Page 6

ELECTRIC POWER FOR CITY TRAMS.

TO THE EDITOR. SIX, —In connection with the acquisition of the city trams by the corporation it is satisfactory to note that it is pru^osed to use electro-motive energy as the driving power. From an advertisement in la3fc week's Times it is evidently in contemplation to utilise the ; Lee (stream and Taieri River, near Mullocky' Gully, for the purpose of generating power, at an estimated outlay of £26,000 for races " and dam. Before power from this source can ■ be made actually available in Dunedin, it is '■ safe to say that the cost will be little, if any- • ; thing, under £40,000. The question then . comes to be, Will the power that can be got for transmission to Dunedin justify such a large expenditure? ' . j Several years ago one of. our local engineers j was employed to make a survey and report on i the Taieri as a source from which to obtain , electric power. His report was submitted to i London capitalists, and the objection to the i scheme was the heavy outlay required in ! order to obtain the estimated power. The ! modification of this scheme is evidently now ; being entertained by our city fathers. Well, ; let tis see how things work out on the basis of the figures and particulars given in the cor->. ■ poration's advertised application coining before the next Warden's Court. Lee Stream: 30 heads, fall not given, but assuming it to be' 600 ft, equal to 2029 horse-power: Taieri River : 350 heads, fall not given, but from the application it would appear a3 if the only ' fall would be the height of the. dam—3oft. To err, however, on the safe,side, and to give the river as much credit as possible, call the fall 70ft, 'that would give 2029 horse-power. The two streams combined would apparently give a power equal to 4790 horse. But this' result is only obtained by assuming as approximately correct the estimated volume of water • in the two. streams, and this will most certainly be found seriously out in times of drought and prolonged frost; and as a large reservoir is evidently not proposed, it is the minimum volume of water that must be • reckoned .with.. The short distance between Mullocky Gully and Dunedin—some 10' miles —is certainly a factor in favour of the scheme as'against taking power from, any more distant source. This gain, however, unless otherthings be about equal, is not so very important. The cost of wire is £300 per mile, and the loss of power in transmission has now, by recent improvements, been reduced to 5 per cent, for distances under' 30 miles. The mayor and councillors deserve' every credit for their evident desire to bestow on the citizens the inestimable boon of cheap motive power. In order to secure this on the' most advantageous terms it is necessary that they keep their eyes and ears open, and not accept the first suggestion that is made; and further, it is necessary to remember that, when an engineer is instructed to report on * particular scheme he is not called on to report outside of his definite instructions. <Is it possible that neither mayor nor councillors have heard of the falls on the Waipori.River, a distance of not more than 2+ miles from' Dunedin? On two separate occasions, and, v after prolonged drought, competent engineers have reported, after careful and exhaustive examination, that at the very least 120 heads with a fall of 360/6, giving a power equal to 4869 horse, can be obtained,! and this for a comparatively small outlay, no expensive works being necessary, and with a race under . one mile in length. Were a dam built; and for which every facility exists in the shape of a narrow, rpek-bound gorge, the available power would be largely increased;-and further, without any dam, by extending race four miles, 600 ft fall can be got, giving; a power equal to 8116 horse. It was from the Waipori River that the New Zealand MineralsCompany .proposed obtaining power to drive their battery at the O.P.Q. mine, and at same time supply power and light to the dredges on the river. The slump in the London share market prevented the scheme being carried out, after £500 cash had been paid to the holders of a right sufficient only to give 1000 horse-power. A copy of the London engi-* neer's report could probably be obtained' on application to the company's colonial representative. At all events, there should be no difficulty in obtaining- a copy of the report recently made by Mr Hutcheson, acting under direct instructions from the warden, should the corporation, grudge the expense of a preliminary examination and report by a competent engineer on its own account.—'l am, etc., . ■ Citizen.'

— In minerals Brazil is probably the richest State in the world. The most attractive pro-, duct at the present time of diamond-dearth is (says the Sun) the beautiful gem which never seems to lose its popularity. Gold there is in plenty. There are six or seven'main diamond districts, the chief being, as its name denotes, Diamantina. It lies along the Serrade Espinhaco, and moat of the streams flowing off it on the side next the Jequitinbonha River contain diamonds. At present the miners work in tlie very simplest and primitive fashion, washing"with the hands, stopping when the rain comes, having no steam, water, or other power, and yet getting diamonds always. ,