trical generating works, which contains a large amount of extremely useful and suggestive information. Much useful information is also contained in the annual reports of the Massachusetts Gas and Electric Light Commission. The subject is also discussed at some length in Calder's treatise on "The Prevention of Factory Accidents," from which are briefly quoted the following remarks:

The special risk from electric shock in connection with the generation and distribution of electricity in factories, workshops, and other premises is one which has increased with the progress in the use of high pressure. A dangerous and possibly fatal shock may be sustained by contact between two portions of the human body or even clothing and two conductors differing in pressure by 700 to 1,200 volts, according to the perfection of the contact. An insulated person safely touching highly charged metal and at the same time passing any conductor to another uninsulated person, or even touching the latter or an earthed conductor, may cause a fatal or severe shock. The metal of the dynamos, the switchboard and connections, the high pressure mains, transformers, and series arc lamps is material from the touching of which under the above conditions dangerous shock would result. The ordinary fencing may be relied upon for protecting moving parts of electrical generating machinery in the case of direct currents below a voltage of 700 and of alternate currents less than 350 volts pressure. All installations with higher voltages should be regarded as high pressure, and the following extra precautions should be adopted in view of the risk from shock. (")

There are few employments which require more serious attention to the risk of accidental injuries than the electrical industries, and as emphasized by the statistics previously quoted, the risk is particularly great in the employment of linemen, where, however, the electrical hazard is increased by the liability to serious falls in the climbing of poles and connecting of wires while at a considerable height above the ground.

ACCIDENTS IN MINES AND QUARRIES.

The accident risk in mines and quarries is a widely distributed one throughout the United States, and every branch of the industry would require special consideration to properly emphasize the specific occupation hazard. There were in 1902, according to the census, 151,516 mines in the United States, giving employment to 581,728 wage-earners and 38,128 salaried officials, clerks, etc.

ACCIDENTS IN COAL MINING.

The most important branch of the industry is coal mining, which during 1902 employed 350,329 wage-earners. The broad division in coal mining is between anthracite and bituminous. The anthracite beds are practically limited to Pennsylvania, while bituminous coal is mined in a large number of States, including the Pacific coast States

a The Prevention of Factory Accidents, by John Calder, p. 114.

and the Territory of Alaska. During the ten years ending with 1906 there occurred in the anthracite regions of Pennsylvania 4,833 fatal accidents and 11,084 nonfatal injuries. The fatal accident liability in anthracite mining in proportion to the number employed was 3.18 per 1,000 and 7.29 per 1,000 for nonfatal injuries. In the bituminous coal fields of Pennsylvania there occurred during the ten years ending with 1906 3,522 fatal accidents and 7,671 nonfatal injuries. In proportion to the number employed the fatal accident rate was 2.77 and the nonfatal accident rate 6.03 per 1,000. The accident liability, both fatal and nonfatal, was, therefore, somewhat greater in the anthracite coal fields than in the bituminous, but the differences are not as great as generally assumed. A more marked difference appears when the accident liability in the soft-coal regions of Pennsylvania is compared with that in the soft-coal regions of certain other States. In Illinois, in the ten years ending with 1906, the fatal accident rate was 2.57 and the nonfatal accident rate 10.67 per 1,000, while in the State of Missouri during the same period the fatal accident rate was only 1.39 and the nonfatal accident rate 2.65 per 1,000. The accident risk in soft-coal mining is very much greater in the far western States, and, for illustration, in the State of Colorado during the ten years ending with 1906 the fatal accident rate in coal mining was 5.87 per 1,000 and the nonfatal rate was 10.74. (a) The details of coal mining accidents in the anthracite fields of Pennsylvania are shown here, but additional tables for other States are given in the statistical appendix.

NUMBER OF FATAL AND OF NONFATAL ACCIDENTS AND RATE PER 1,000 EMPLOYEES IN THE ANTHRACITE COAL MINES OF PENNSYLVANIA, BY YEARS, 1897 TO 1906.

[Compiled from the Annual Reports of the Pennsylvania Department of Mines.] Nonfatal accidents.

Fatal accidents.

Number of

Rate per

Rate per

ployees.

ployees.

149,557

423

2.83 1,106

7.40

142, 420

411

2.89

1,134

7.96

140,583

461

3.28

1,030

7.33

a For a further discussion of coal mining accidents by the writer, see articles in the Mineral Industry, volume 6, New York, 1897, and in the Engineering and Mining Journal for January 27, 1900; November 24, 1900; August 10, 1901; October 25, 1902; September 5 and 26, 1903; December 22, 1904; December 2, 1905; December 22, 1906, and January 4, 1908. For a discussion of the conditions of labor and life in anthracite mining by the writer, see the Engineering and Mining Journal for November 22 and 29 and December 13 and 20, 1902.

NUMBER OF FATAL AND OF NONFATAL ACCIDENTS AND RATE PER 1,000 EMPLOYEES IN THE BITUMINOUS COAL MINES OF PENNSYLVANIA, BY YEARS, 1897 TO 1906.

[Compiled from the Annual Reports of the Pennsylvania Department of Mines. figures for each year are as shown in the report for that particular year.]

The

In metal mining the most important branch is iron-ore mining in the Lake Superior region. The mining of iron ore in the aggregate gives employment to about 40,000 wage-earners. The most trustworthy data are for Dickinson and Marquette counties, Mich. During the ten years ending with 1906 the fatal accident rate in the iron mines of Dickinson County was 4.23 per 1,000, while the nonfatal accident rate was 3.80. But the term "accident" in this case is limited to serious injuries. The accident rate has varied considerably from year to year, having been as high as 7.79 per 1,000 in 1901 and as low as 2.54 per 1,000 in 1902. The fatality rate of persons employed inside of the mines during the ten-year period was 4.95 per 1,000, while the fatality rate outside of the mines was 2.53 per 1,000. In Marquette County during the same period the fatal accident rate was 4.31 per 1,000, having been as high as 5.58 in 1901, and as low as 3.62 in 1900.

The details of the accident frequency during each of the years of the ten-year period are given in the following table. An additional table showing the frequency of inside and outside accidents in the mines of Dickinson County is given in the appendix, Table VIII.

NUMBER OF FATAL AND OF SERIOUS NONFATAL ACCIDENTS AND RATE PER 1,000 EMPLOYEES IN IRON-ORE MINES OF DICKINSON COUNTY, MICH., BY YEARS, 1897 TO 1906.

NUMBER OF FATAL ACCIDENTS AND RATE PER 1,000 EMPLOYEES IN IRONORE MINES OF MARQUETTE COUNTY, MICH., BY YEARS, 1897 TO 1906.

ACCIDENTS IN LEAD AND ZINC MINING.

The mining of lead and zinc is chiefly concentrated in Missouri. The returns for the metalliferous mines of that State may, therefore, be accepted as representative of this industry. During the ten-year period ended with 1906 the fatal accident rate in Missouri lead and zinc mines was 3.01 per 1,000 and the nonfatal accident rate 1.69. The fatal accident rate has varied considerably from year to year, having been as high as 4.49 per 1,000 in 1900, and as low as 1.23 per 1,000 in 1902. The mining of lead and zinc ores as a separate industry gives employment to about 8,000 (a) wage-earners throughout the United States. The details of accident frequency in the lead and zinc mines of Missouri, including the mills, are set forth in the following table.

a 7,881, according to Census Report on Mines and Quarries, 1902, p. 445.

NUMBER OF FATAL AND OF NONFATAL ACCIDENTS AND RATE PER 1,000 EMPLOYEES IN LEAD AND ZINC MINES OF MISSOURI (INCLUDING THE MILLS), BY YEARS, 1897 TO 1906.

[Compiled from the Annual Reports of the Missouri Bureau of Mines and Mine Inspection.]

Copper mining gives employment to about 26,000 wage-earners, chiefly in the State of Montana, the Lake Superior region, and in Arizona. The most trustworthy data regarding the accident liability in copper mines are for Houghton County, Mich., for the ten years ending with 1903. The data are limited to fatal accidents, apparently no returns being required for nonfatal injuries. The recorded fatal accident rate was 2.80 per 1,000 for the ten-year period, having been as high as 6.35 per 1,000 in 1895, and as low as 2.07 per 1,000 in 1899. The details of fatal accident frequency in the copper mines of Houghton County, Mich., are set forth in the table below:

NUMBER OF FATAL ACCIDENTS AND RATE PER 1,000 EMPLOYEES IN COPPER MINES OF HOUGHTON COUNTY, MICH., BY YEARS, 1894 TO 1903.

[Figures for 1894 to 1902 from Twenty-first Annual Report of the Michigan Bureau of Labor, p. 119; figures for 1903 from the Engineering and Mining Journal.]

Since copper mining in Montana constitutes the predominating branch of the mining industry in that State, the accident returns for