It is to be understood, however, that the manufacture and of electrical ap paratus and material is but a small part of the electrical industry as a whole. The total capitalization is placed as high as $12,000,000, 000, the gross sales and earnings are rated at above $2,500,000,000, and the number of persons employed at more than 1.000,000. The ac companying figures were published during 1916 which while based on earlier data can be shown to be in many respects far short of the actual ity. A conservative estimate for the total service and output 'value of electricity in 1917 As to the production of apparatus alone, three concerns reported a total around $300, 000,000, and one concern reported at the end of 1917 orders on hand to the value of $240, 000,000. The increase is by no means wholly in output but must take into consideration the increase in prices as exhibited in the following table which, while applying principally to elec tric street railway material, is pertinent in many respects to the electrical field as a whole: Electric Light and Power Statistics.— It is unfortunate that the authoritative statistics as to the four great groups of electrical public utilities which manufacture ((service) as com piled by the government — telegraphy, tele phony, electric light and power • and electric street railways—do not come down to a later period than 1912. Their figures under an act of Congress are taken by the United States Bureau of the Census every five years, the last being compiled in 1912 and the next not being due until 1917, and not becoming available be fore the end of 1918 at the earliest. The data for 1912 are therefore presented herewith sub ject to the expansion up to date under the average rates of increases that are apparently revealed.
6,000,000 customers in 1916. At least 10,000,000 devices for consuming current, outside of power and light purposes, were then in circuit — flat irons, vacuum cleaners, coffee percolators, grills, toasters, etc.—but electrical refrigeration except in bulk and especially in the production of craw water" ice had not advanced very far. In the use of electric power some States in the South and on the Pacific Coast showed enor mous gains in the period 1905-12, running up to 4,000 per cent, due in both sections to the utilization of water power, and in the South to the electrification of the cotton goods industry as a whole. As to lighting, one of the most interestinig developments has been the relative supersession of arc lighting for street and com mercial purposes by the incandescent lamp, al Various items in connection with the central station electric light and power industry may here be noted. Statistics as to its income are regularly compiled by the Electrical World on a basis in excess of 60 per cent of the totals re ported from month to month; and these show for 1916 an income of not less than $425,000,000 from electrig service. If the return from other service such as sale of electrical supplies, steam heating, refrigeration and return on investments be considered, the total 1915-16 income of the industry cannot possibly be put lower than $450,000,000, and it is probably far in excess of that. The number of electric meters on all
central station consumption circuits in 1912 was 3,617,189, coinciding very closely with the number of customers, and it is estimated on this basis and others that there were not less than though in projection and searchlight use it has made such strides that an arc search light operating in New York has made its beam visible in Philadelphia, 90 miles away. There is also a large use of arc lights in theatrical and motion picture work. Owing to the ad vancing perfection of the incandescent lamp through the stages of carbon, metallized car bon, tantalum and tungsten filaments, the num ber of spherical candle power hours delivered for one cent has risen from 13.9 in 1885 to 71 in 1916, an increase of nearly 500 per cent in about 30 years, during which time the price of the lamp and the price of electrical energy have both decreased enormously. The rate here given is figured on operation at 1,000 hours of energy at 10 cents per kilowatt hour for current.
Among the chief advances of the period in electrical development outside of railway work have been those in electro-chemical and electro metallurgical development, both stimulated un doubtedly by the great war and both dependent upon the supply of cheap current. Thus one plant building in 1916 in California was to use 2,500 horse power of electrical energy generated by a hydro-electric company, with an output of 5,000 tons of caustic soda and 10,000 tons of *bleach.° The electrolytic production of hydro gen and oxygen has increased enormously, so that over 300,000,000 cubic feet of hydrogen per year are thus manufactured in the United States. It is interesting to note, however, that while the electrical fixation of atmospheric nitrogen has increased enormously abroad, representing about 300,000 tons at the beginning of 1916, or a gain of over 200 per cent in three years, requiring 1,000,000 horse power, little corresponding activity has been shown in the United States up to this time of writing; al though several processes of proved value are of American origin. On the contrary, the develop ment of the electric steel furnace has been re markable. Electrical castings command a pre mium where unusual durability and resistance to stress are needed. On 1 Jan. 1916, about 73 electric steel furnaces were in operation in the United States with an output of about 100,000 tons per year, but a terrific jump was made during 1916, so that the number of American furnaces was at least doubled, while their out put has been estimated at 1,000.000 tons by a conservative authority. Probably the United States has now more electric furnaces than any other country.