588 



NA TURE 



[April 23, 1903 



But these lists, valuable as they are, contain but a 

 very small portion of the results we may hope for. 

 The committees on sections used in ship building, on 

 locomotives, and on electrical plant, each appeal to 

 an enormous industry, and in each of these there is 

 much that can be standardised. Take, for example, 

 the various sizes and speeds used in dynamos and 

 motors, the numerous voltages in electric light and 

 power systems, and the varying frequencies of alter- 

 nators. The committee on electrical plant, of which 

 Sir Wm. Preece is chairman, has subcommittees on 

 electric generators, motors, and transformers under 

 Colonel Crompton, on telegraphs and telephones under 

 Mr. Gavey, and on cables under Mr. R. K. Gray. 



Both in America and in Germany committees on 

 the standardisation of electric plant have reported 

 within the last few years, and the value of their work 

 is generally recognised ; their results will be of dis- 

 tinct service to the English committee when the time 

 comes to frame its report. Meanwhile one important 

 industry has already acted. The lists of standard sizes 

 issued by the Cable Makers' Association carry out in 

 an admirable manner the principle of standardisation. 



There is no doubt that the belief expressed by the 

 association that the adoption of these standards will 

 act equally for the benefit both of the purchaser and of 

 the manufacturer is well founded, and it is greatly 

 to be hoped that they may be adopted. 



Standardisation, of course, has its dangers; it may 

 tend to crystallise the form of products, and thus to 

 delay progress. These possible dangers are clearly 

 before the minds of the practical men who form these 

 various committees, and will have due consideration 

 in their reports. Meanwhile, we can only repeat that 

 the need for standardisation is enormous, and its 

 advantages immense. 



The announcement contained in the papers recently 

 that a vote of 3000?. for the work of the committee 

 is to be included in the estimates for 1903-1904 is a 

 gratifying recognition of the value of its work, and 

 Sir Francis Hopwood expresses the view of all quali- 

 fied to judge when in his letter intimating this grant 

 he writes : — 



" The Board of Trade desire me to state that they 

 regard the work undertaken by the committee, in- 

 cluding as it does the preparation of standard speci- 

 fications for engineering works, and of standard 

 sections of rolled iron and steel, together with the 

 standardisation of parts of locomotives and electrical 

 appliances, as tending to reduce both the cost of pro- 

 duction and the time occupied in completion, and as 

 being of the highest value to the country at large." 



But, as has been already said, the work yet accom- 

 plished is but a small fraction of that which remains 

 to be done, and the further reports of the committee 

 will be eagerlv expected bv engineers. 



ITALIAN VISIT OF THE INSTITUTION OF 

 ELECTRICAL ENGINEERS. 



'PHE Institution of Electrical Engineers has just 

 1 completed a visit to northern Italy to inspect the 

 chief works of engineering interest. The Institution 

 has made several continental visits of this kind during 

 the last few years, and although it is difficult to gather 

 much in the way of detail on such occasions, it never- 

 theless seems to be helpful to many to get some general 

 ideas of what our neighbours are doing, and at the 

 same time to get the advantage of a little pleasure 

 from the scenery which, in this case, is among the 

 most beautiful to be found in Europe. 



Probably the piece of work that was looked forward 



NO. I 747, VOL. 67] 



to with the greatest interest was the electric railway 

 from Lecco to Sondrio and Chiavenna on the Ganz 

 system, as it forms a bold experiment, and is the first 

 of its kind. The total length is sixty-three miles. The 

 electric energy is generated by three-phase machines 

 at 20,000 volts, and is transformed down at nine points 

 along the line to 3000 volts, this comparatively high 

 voltage being taken direct by the trolley to the motors. 

 Voltage as high as this necessitates many unusual 

 precautions of an interesting kind ; for example, the 

 rheostats and switches are worked pneumatically, so 

 that the driver does not operate direct any apparatus 

 subject to high tension. The method of coupling up 

 the motors is also interesting from its novelty. In- 

 stead of working the motors in the usual way, they 

 are divided into high and low tension motors. The 

 high pressure current is taken only to the stators of 

 the high tension motors ; the rotors of these machines 

 are used to supply low tension three-phase current to 

 the stators of the low tension motors. The low tension 

 motors are thus supplied with current at a lowei 

 frequency than the main current. This " cascade '' 

 method of working is continued until half speed is 

 attained, when the low tension motors are cut out and 

 full speed is reached on the high tension motors alone. 



The recent arbitration, in which it was decided not 

 to use the Ganz system for the Metropolitan Rail- 

 way, is still fresh in the minds of most people. 

 Although this system does not seem so suitable for 

 cases in which the acceleration at starting and the 

 speed must be high, it should certainly afford a cheap 

 method of working long lines not having much traffic. 

 As seen at Valtellina, the ease and smoothness of work- 

 ing were all that could be desired. 



On looking at the boldness of the experiment, one 

 cannot help being struck by the difference between 

 Italy and our own country in taking up a thing of this 

 kind. But it must not be forgotten that one of our 

 greatest sources of wealth tends to keep us from using 

 electrical methods. If the price of coal were double 

 its present value, which is the sort of price which 

 holds in Italy, then the coal bill would be a larger pro- 

 portion of the whole cost, and it would be more worth 

 while to attempt a saving. 



The usual form of electric traction by means of 

 direct current at 650 volts, transformed from high 

 tension three-phase, was seen on the line from Milan 

 to Gallarate and Porto Ceresio. This line is forty-seven 

 miles in length, and also differs from that to 

 Valtellina in having much heavier traffic and higher 

 speeds, and in being partly worked by steam. It is 

 therefore of great interest to those who are at present 

 considering the electrical working of our main lines. 



Overhead lines are, of course, a feature of every 

 long-distance transmission. It does not seem to be 

 generally realised how much we have to pay for putting 

 all conductors underground, though this subject will 

 no doubt come forward more prominently when our 

 large power distribution companies get really to work. 

 One disadvantage of overhead lines is that they are 

 subject to lightning' discharges. Many protecting 

 devices have been tried, and a particularly interesting 

 one was seen at the Monbegno generating station on 

 the Valtellina line. It consisted of jets of water form- 

 ing a permanent earth, but of such a resistance that 

 the loss does not amount to more than about 2 kilo- 

 watts. The action is said to be very satisfactory. 



At Milan several large works were visited, and also 

 the Royal Technical Institute. The latter is not very 

 large, but is usefully equipped. The room for elec- 

 trical measurements contains instruments in one group 

 for measuring all the usual quantities over a wide 

 range. In the motor and dynamo testing room the 



