158 SECTIONAL ADDRESSES. 



when he laid the St. Pancras 5-wire system ; the space occupied under 

 the streets over thirty years ago by electrical mains would not be available 

 or allowable to-day. 



An extension of the useful radius of direct-cmrent supply was made 

 in this city and came to be known as the Oxford system ; this was applied 

 to several other localities. Electricity was generated at 2,000 volts direct 

 current, or thereabout, and transmitted to sub-stations in which motor 

 generators reduced the pressure to that required for local distribution 

 and service to consumers, thus enabling a wider radius to be suppUed from 

 the generating station. 



In those days great benefits were derived from the engineering skill 

 of Willans, whose high-speed single-acting engines were largely used iu 

 the power stations of that time, and later from the splendid double-acting 

 high-speed engines built by Belliss & Morcom and other well-known makers 

 of high-speed sets. 



It was not uncommon then to construct non -condensing generating 

 stations, largely owing to the low load factor of the system ; the con- 

 sumption of coal per unit generated was correspondingly great and wasteful. 



It is interesting to note how far we have progressed by comparing the 

 ideal put forward by Colonel Crompton thirty-two years ago with present- 

 day results. 



The ideal cost of production was then placed at 1.^2d., excluding capital 

 charges, and the average price to the consumers 3d. It is true that the 

 load factor was only 20 per cent, and the capital outlay then as much as 

 £125 per kw.i. At the present time the average revenue from all classes 

 of consumer is 1.15d. — the average station load factor 29 per cent, and the 

 capital outlay £52 per kw. 



Far too little credit has been given to the pioneer work of Dr. Ferranti, 

 who was the first to advocate generation on a large scale and transmission 

 by high pressure over an extensive area of supply. It was he, in fact, who 

 initiated this system at Deptford, necessarily limited to single-phase 

 current in those early years. The principles now generally accepted were 

 enunciated by him many years ago. 



Then came the revolutionary discovery of the practical application of 

 multi-phase currents, with all the attendant advantages arising from 

 simpler construction of machinery, easy transformation by means of static 

 apparatus, efiicient long-distance transmission and facile application to 

 appliances for lighting, power, or heat. This immensely Avidened the 

 economic area of supply, and when a little later that illustrious pioneer. 

 Sir Charles Parsons, after persistent and indefatigable research from 1884 

 onwards, at length overcame his initial difficulties, and about the year 

 1892 gave the electricity industry the steam turbine, so peculiarly fitted 

 to the driving of 3-phase generators, electrical engineers at last possessed 

 an equipment which enabled them to revolutionise the methods adopted 

 in former years. Thereafter, all important power stations gradually changed 

 over from reciprocating engines to the steam turbine, A^dth its enormous 

 gain in higher revolutions per minute, a factor of so fundamental an import- 

 ance in the design and cost of modern electric generators. At the present 

 time, reciprocating-engine sets represent only 8 per cent, of the total 

 prime movers employed in public power stations, and their proportion is 



