he good news was published. But he could not, even in the first
moments of rejoicing, forget that the cause of congratulation was only a
pardon for an offence which he had never committed, and for which he had
been enduring heavy punishment during sixteen years of his life.

CHAPTER XXIV.

THE INTENTIONS AND DISCOVERIES OF LORD DUNDONALD'S FATHER.--HIS OWN
MECHANICAL CONTRIVANCES.--HIS LAMPS.--HIS ROTARY STEAM-ENGINE, HIS
SCREW-PROPELLER, HIS CONDENSING-BOILER, AND HIS LINES OF
SHIP-BUILDING.--THEIR TARDY DEVELOPMENT.--HIS CORRESPONDENCE UPON
STEAM-SHIPPING WITH SIR JAMES GRAHAM, THE EARL OF MINTO, THE EARL OF
HADDINGTON, AND THE EARL OF AUCKLAND.--THE PROGRESS OF HIS
INVENTIONS.--THE "JANUS."--THE BENEFICIAL RESULTS OF HIS EXPERIMENTS.

[1833-1847.]

Lord Dundonald's father, the ninth earl, had devoted the chief energies
of his long life to scientific pursuits, which won for him, not profit,
but well-earned fame, and which proved of immense benefit to his own and
succeeding generations. By him was discovered the art of extracting tar
from coal, and out of that discovery was developed, partly by him and
partly by others, the manufacture of gas, first used for lighting his
tar-works. The important chemical process of making alkali and crystals
of soda was also introduced by him, whereby a great impetus was given to
the manufacture of glass and to many other important branches of
industry. He discovered the present method of preparing alum, or
sulphate of vitriol, and suggested its substitution for gum senegal,
which has proved hardly less advantageous to the mechanical arts. In
1795, he published a treatise, the result of numerous and costly
experiments, on the connection between agriculture and chemistry, which
was almost the parent of all the later researches that have issued in
beneficial plans for improving the soil and invigorating the growth of
crops, and in various and important developments of scientific farming.

The tenth Earl of Dundonald inherited his father's mechanical and
scientific genius. The lamp invented by him in 1814, which introduced
the principle upon which all later lamps for burning oil, naphtha, and
other combustibles have been constructed, has been already referred to.
Many other inventions and discoveries occupied his leisure during the
years in which he was allowed to follow his profession both in British
and in foreign service;[15] and the fuller leisure forced upon him
during t