brick, originally used, was ordinarily burnt out in two charges of twenty minutes each.

Another important modification in the process related to the kind of metal subjected to conversion, and its after treatment. In his earliest experiments, Mr. Bessemer had, by accident, made use of a pure Blaenavon iron; but in his subsequent trials, iron of an inferior quality had been subjected to conversion, and the results were much less satisfactory. It was found that the high temperature and copious supply of air blown through the metal had failed to remove the sulphur and phosphorus present in the original pig, and that the product was an inferior metal. After a long series of experiments, Mr. Bessemer at length found that the best results were obtained from Swedish, Whitehaven, Hæmatite, Nova Scotian, or any other comparatively pure iron, which was first melted in a reverberatory furnace, before subjecting it to conversion, in order to avoid contamination by the sulphur of the coal.

Finally, to avoid the risk of spoiling the metal while under conversion by the workmen stopping the blast at the wrong time, Mr. Bessemer adopted the method of refining the whole contents of the vessel by burning off the carbon, and then introducing a quantity of fluid carburet of iron, containing the exact measure of carbon required for the iron or steel to be produced.

When Mr. Bessemer, after great labour and expense, had brought his experiments to a satisfactory issue, and ascertained that he could produce steel of a quantity and texture that could be relied on with as much certainty as any other kind of metal, he again brought the subject of his invention under the notice of the trade; but, strange to say, not the slightest interest was now manifested in it. The Bessemer process had been set

down as a failure, and the iron and steel makers declined to have anything to do with it. The inventor accordingly found that either the invention must be abandoned, or he himself must become steel manufacturer. He adopted the latter alternative, and started his works in the very stronghold of steelmak ing, at Sheffield, with a success which is matter of history.

The great value of this invention is unmistakably shown by the fact that 500,000 tons of steel were, in 1874, being made annually by the Bessemer process in Great Britain, the total number of converting vessels in use being ninety-one, and their aggregate capacity 467 tons. Large quantities are also manufactured by it in Sweden, Russia, Austria, Prussia, and other European countries. In America it is likewise extensively employed.

A recent experimental trial is reported, which is said to have been quite fairly conducted: as the result, it was found that a Bessemer steel rail lasted fully longer than twenty iron ones.

JOHN ERICSSON.

N a mountain hamlet in a beautiful district of Central Sweden, near the iron mines of Langbanshyttan, stands in front of a miner's cottage a granite-shaft eighteen feet high, with this inscription in golden letters

JOHN ERICSSON

WAS BORN HERE IN 1803.

September 3, 1867, when this monument was unveiled, was a gala day in the mining districts; all work was suspended, and crowds gathered from far and near to do honour to their distinguished countryman, whose fame is world-wide, and of whom they may well be proud.

John Ericsson is the son of Olof, a Swedish miner; his mother was a woman of intelligence and refinement; John's brother, Mils, distinguished himself highly in his native country as an engineer of canals and railroads, and was raised to the rank of Baron by the King of Sweden.

John Ericsson's genius developed early. His childish toys were machinery and tools of his own construction. At nine years of age he saw through one of the draught offices on the grand ship canal of Sweden, and there caught some idea of how to use the drawing instruments. This knowledge was put to use in most ingenious ways. Accompanying his father to a pine forest, where

he went to select timber for lock gates on the canal, the miniature draughtsman set himself to construct a pair of compasses of birch wood, with needles stuck in the ends of the legs; his good-natured mother allowing him to convert a pair of steel tweezers, taken from her dressing-case, into a drawing pen, also to take hair from her sable-cloak for paint brushes.

It may be mentioned that Ericsson's grandfather by the mother's side was a man of property; which, however, was lost in some mining speculations, so that young Ericsson began life in poverty, which was perhaps fortunate for the development of his genius.

Before he was eleven Ericsson had constructed a sawmill and planned a pumping-engine for the purpose of clearing the mines of water. He had much difficulty in perfecting this plan, as it was intended to be operated by a windmill, which he had never seen; at last his father visited one, and after hearing his description he was able to finish it.

The

This may be said to be the turning-point in his career. plan was shown to Admiral Count Platen, President of the Gotha Ship Canal, on which Ericsson's father was then employed. The Count, amazed at the genius displayed by such a mere child, uttered the encouraging and prophetic words, "Go on as you have begun, and you will one day produce something extraordinary." He was appointed a cadet in the Swedish corps of mechanical engineers at the age of twelve, and at thirteen was appointed a nevelleur (leveller) on the part of the canal over which Count Platen presided. Six hundred troops working on this canal were directed by this boy, and it is amusing to note that one of his attendants carried a stool to enable the small engineer to reach his levelling instruments.

Many important works on the canal were constructed from

Ericsson's plans at this early period. His contact with military men incited him, much against Count Platen's will, to become a soldier, and he entered the army as an ensign. He was very soon promoted to a lieutenancy.

The posts of government surveyors being open to competition by military officers, Ericsson entered his name as a competitor, and of course he gained a prize. His industry in his new employment was most untiring; maps which he executed at this period are still preserved at Stockholm. Not satisfied with doing more work than others in this employ, he directed his energies to the drawing and engraving plates for the illustration of a work on the Gotha Canal. He invented a machine engraver for this work. He next turned his attention to the construction of a flame-engine. One was made with ten-horse power, and was successful. Ericsson now obtained leave to go to England; he arrived there in 1826 with his invention, and did not return to his native country. He sent in his resignation from the army, which was not accepted until he had been promoted to the post of captain, and then only with much regret. Alas! for the flame-engine; it proved a failure with the English sea-coal. He had to begin and experiment anew, and was at last successful in getting a machine constructed and patented and sold to John Braithwaite, who was a friend in need to the inventor. His inventions at this time are said to have been, "A pumping-engine on a new principle, engines with surface condensers and no smoke-stack, and blowers supplying the draught, applied to the steamship Victory in 1828. Apparatus for making salt from brine; mechanism for propelling boats on canals; a hydrostatic weighing machine, to which the Society of Arts awarded a prize; an instrument now in extensive use for taking soundings independently of the length of the lead-line; a file