but not even the Interstate Commerce Commission knows how many boilers were blown up to accomplish this result.

From unofficial sources it may be learned that in 1907 there were 57 locomotive boiler explosions, which means. that one out of each thousand in use that year blew up, killing 101 persons, or nearly one-fourth of the total killed in boiler explosions that year, and injuring 68. In 1909, there were 42 explosions of locomotive boilers, which was 7.6 per cent of the total number of explosions, in which 44 persons were killed, which

Those who can read of these disasters on the railroad and in the saw-mill with complacency may have their equanimity disturbed upon learning that the greatest number of explosions credited to any one class of boilers in 1909 occurred in heating apparatus. No fewer than 68 boilers used in heating office buildings, churches, theaters, schools, asylums, homes, apartments and private houses blew up in the course of the year. This, it must be remembered, is not given as the complete total but only as the number known. Only 10 were killed and 18 in

jured, but surely the angels must have been on guard to prevent some fearful slaughters. For instance, a boiler directly under the dining room of the Windermere Hotel in Chicago blew up January 21, 1906, killing a woman guest and doing $25,000 damage. The explosion occurred at 5:33 a. m. Had it occurred during the breakfast hour dozens would have been killed, for the dining room was totally wrecked. Again, forty girls were about to march into a room in St. Joseph's Orphan Asylum in Philadelphia when a cast iron heating boiler under the room blew up, completely wrecking it. A moment later and that explosion must have resulted in heavy loss of life. On May 11, 1909, a On May 11, 1909, a heating boiler in a school at Centralia, Penn., blew up. There was a panic in which a number of pupils jumped from second story windows yet none was seriously hurt. A St. Paul doctor and his family of five were just about to enter

the dining room of their home for breakfast when a heating boiler beneath blew up, wrecking the dining room completely and nearly demolishing the house.

As for property destroyed in these explosions of heating boilers only a few fragmentary figures are available. One apartment house boiler explosion in Chicago last year caused a loss of $10,000; another $5,000. The explosion of a heating boiler at Toronto caused a loss of $50,000. A boiler in a private residence at Sandy Hill, New York, blew up, starting a fire which destroyed the house. A heating boiler explosion at Park City, Utah, December 12, 1909, started a fire which caused a loss of $26,500. Another fire starting in the same way in the same month in a private residence in Milwaukee did $18,000 damage. A boiler explosion in a Kansas City office building December 6 caused a loss of $47,500, without the aid of a fire.

From the foregoing it may be seen

that no section and no class is free from the menace of the boiler. Wherever water is confined with a fire beneath it there is danger. Why, an insignificant little boiler used to run a steam mangle blew up in the Ideal Laundry in Chicago September 22, 1906, injuring three girls. The boiler in F. A. Dennett's steam automobile blew up at Manitowoc, Wis., June 28, 1909, destroying the auto and injuring the owner. Some boys at play Some boys at play in Iuka, Miss., October 30, 1909, started a fire in a small unused boiler without permission. It blew up, killing one of them and scalding three others severely.

Boiler explosions sometimes have strange results. Thus, a Santa Fe locomotive which blew up at Pinole, Cal., September 29, 1906, started a grass fire which nearly destroyed the town. The plant of the Edison Company at Grand Rapids, Mich., achieved the unprecedented distinction of two different boiler

explosions, a few hours apart, on the same day, August 28, 1909.

Generally speaking, there is nothing left to blow up after one explosion. At Lynn, Mass., December 6, 1906, a boiler blew up, starting a fire which destroyed property valued at $500,000. The accident occurred a few minutes before 7 o'clock in the morning when there were but 20 persons in the building. Of these 17 were injured. Generally the consequences are more serious.

One boiler in a battery of ten at Swift's packing house in Chicago blew up November 29, 1902, killing 13 men and injuring 20. Seven boilers exploded simultaneously in the Geyser Avenue plant of the St. Louis Traction Company December 21, 1903, killing 8 and injuring 21 and doing damage estimated at $75,000.

One of the boilers on the Delaware River steamboat City of Trenton blew

up in 1907, hurling the main upper decks into the river, killing 27 persons and injuring 50. A boiler in the U. S. gunboat Bennington blew up while the vessel was lying at anchor at San Diego, Cal., July 21, 1905, killing 62 men outright and wounding 40 out of a crew of 197. Three boilers in a battery of seven at the mills of the American Tin-Plate Company at Canton, Ohio, exploded May 17, 1910, killing 14 and wounding 30.

The most terrible disaster in the history of transportation on river, sea or land was the boiler explosion on the steamboat Sultana on the Mississippi River a few miles above Memphis about 3 o'clock on the morning_of April 27, 1865. The Sultana was going up the river with 1,866 Union Soldiers, of which 33 were officers, who had just been released from Confederate prisons. She also carried 70 cabin passengers and a crew of 85, making a total of 2,054 on board. The boiler, which had been patched a few days before,

blew up with fearful violence, killing many outright and hurling others into the river to drown. The boat took fire immediately after the explosion and was completely destroyed. Of the soldiers on board 1,101, including 19 officers, lost their lives and 137 of the other passengers and crew were also killed, making the total death roll 1,238.

It is often said that one cubic foot of boiling water under pressure equals in explosive force a pound of dynamite. Like most popular sayings this does not mean anything, and is founded on

nothing tangible; but at least it may remotely suggest the fearful violence of a boiler explosion. Perhaps it may also help to say that a saw-mill boiler which blew up at Kerrick, Minn., May 11, 1909, killing 5 men and wounding 4, hurled debris a distance of a quarter of a mile.

Somebody took the trouble to calIculate the mechanical energy expended in the explosion of a boiler in the shoe factory

of R. B. Grover & Company, at Brockton, Mass., March 20, 1905. The explosion blew down one four-story wooden building and partly wrecked other sections of the plant, killing 58 employes and wounding 117 out of a total of 400 in the factory, and starting a fire which spread to other buildings causing a total loss of $250,000. The boiler was 17 feet long and 6 feet in diameter and contained 140 three inch tubes. At the time of the explosion it contained about 240 cubic feet of water and 103 cubic feet of steam at 90 pounds pressure. The sudden release of this quantity of steam and water from 331 degrees in the boiler to the temperature of the atmosphere, developed mechanical energy equal to 568,643,000 foot pounds. If properly applied this would have been sufficient to lift the boiler and its contents, weighing 30,000 pounds, 18,954 feet, or 3.5 miles.

All this is merely a paper calculation. The boiler was not actually lifted three miles and a half into the air. Once, and once only, it has been possible to measure with a fair degree of accuracy the height to which a boiler was thrown by an explosion. A four hundred horse power water tube "safety" boiler, one of a battery of 17 in the power plant of the Den

ver, Col., Gas and Electric Company blew up June 15, 1909, killing 6 and injuring 4, and doing $60,000 damage. A part of the boiler was shot up through the roof like a rocket by the action of the steam emitted from the broken tubes. It went up to a great height and fell back through another part of the building. A man named Harley was sitting in an office on an upper floor of a building more than half a mile away. Hearing the sound of the explosion he looked out of the window in time to see the boiler as it turned at the height of its flight. He saw it just over the sash of the window which was partly raised. Over the sill he could see the ball on top of a flagstaff on another building. By measuring the distances from his chair to the window, to the ground, to the flagstaff, to the scene of the explosion and taking the angle from the eye of the observer over the sill and over the sash it was possible to work out the height of the boiler when seen. This was 1,659 feet.

But to return from the specific to the general: the only statistics compiled on the subject of boiler explosions in the United States are those gathered by the Hartford Steam Boiler Inspection Insurance Company, and it is not pretended