0 he laid down the clipper ship the
_Challenger_. About the same time, Messrs. Jardine, Matheson, and Co.
gave an order to an Aberdeen firm of shipbuilders, Messrs. Hall and Co.,
to build two sharp ships on the American model, but of stronger
construction. These vessels were named the _Stornoway_ and _Chrysolite_,
and were the first of the celebrated class of Aberdeen clippers. They
were, however, only about half the dimensions of the larger American
ships, and were, naturally, no match for them in sailing powers. The
_Cairngorm_, built by the same firm, was the first vessel which equalled
the Americans in speed, and, being of a stronger build, delivered her
cargo in better condition, and consequently was preferred. In 1856 the
_Lord of the Isles_, built by Messrs. Scott, of Greenock, beat two of
the fastest American clippers in a race to this country from China, and
from that time forward British merchant vessels gradually regained their
ascendency in a trade which our transatlantic competitors had almost
made their own.

[Illustration: FIG 73.--The _Great Republic_. American clipper. 1853.]

It was not, however, by wooden sailing-ships that the carrying trade of
Great Britain was destined to eclipse that of all her rivals. During a
portion of the period covered in this chapter, two revolutions--one in
the means of propulsion, and the other in the materials of construction
of vessels--were slowly making their influence felt. About twelve years
before the close of the eighteenth century the first really practical
experiment was made on Dalswinton Loch, by Messrs. Miller and Symington,
on the utilization of steam as a means of propulsion for vessels. An
account of these experiments, and of the subsequent application and
development of the invention, are given in the "Handbook on Marine
Engines and Boilers," and need not, therefore, be here referred to at
greater length.

The other great revolution was the introduction of iron instead of wood
as the material for constructing ships. The history of that achievement
forms part of the subject-matter of Part II. During the first half of
the nineteenth century, good English oak had been becoming scarcer and
more expensive. Shortly after the Restoration the price paid for
native-grown oak was about L2 15_s._ a load, this being double its value
in the reign of James I. The great consumption at the end of the
eighteenth and the beginning of the last century had so diminished the