Inventions in the Century

by William Henry Doolittle

But in other respects the ideas of Noah and of the Phœnicians, the best of ancient ship-builders, as well as the Northmen, the Dutch, the French, and the English, the best ship-builders of later centuries, were decidedly improved upon by the Americans, who, as above intimated, were revolutionizing the art and building the finest vessels in the early part of the century, and these rivalled in speed the steam vessels for some years after steamships were ploughing the rivers and the ocean.

Discarding the lofty decks fore and aft and ponderous topsides, the principal characteristics of the American “clippers” were their fine sharp lines, built long and low, broad of beam before the centre, sharp above the water, and deep aft. A typical vessel of this sort was the clipper ship Great Republic, built by Donald McKay of Boston during the first half of the century. She was 325 feet long, 53 feet wide, 37 feet deep, with a capacity of about 4000 tons. She had four masts, each provided with a lightning rod. A single suit of her sails consisted of 15,563 yards of canvas. Her keel rose for 60 feet forward, gradually curved into the arc of a circle as it blended with the stern. Vessels of her type ran seventeen and eighteen miles an hour at a time when steam vessels were making only twelve or fourteen miles an hour, the latter speed being one which it was predicted by naval engineers could not with safety be exceeded with ocean steamships.

These vessels directed the attention of ship-builders to two prominent features, the shape of the bow and the length of the vessel. For the old convex form of bow and stern, the principal of an elongated wedge was substituted, the wedge slightly hollowed on its face, by which the waters were more easily parted and thrown aside.

A departure was early made in the matter of strengthening the “ribs of oak” to better meet the strains from the rough seas. In 1810 Sir Robert Seppings, surveyor of the English navy, devised and introduced the system of diagonal bracing. This was an arrangement of timbers crossing the ribs on the inside of the ship at angles of about 45°, and braced by diagonals and struts.

Of course the great and leading event of the nineteenth century in the matter of inventions relating to ships was the introduction of steam as the motive power. Of this we have treated in the chapter on steam engineering. The giant, steam, demanded and received the obeisance of every art before devoting his inexhaustible strength to their service. Systems of wood-working and metal manufacture must be revolutionised to give him room to work, and to withstand the strokes of his mighty arm. Lord Dundas at the beginning of the century had an iron boat built for the Forth and Clyde Canal, which was propelled by steam.

But the departure from the adage that “ships are but boards” did not take place, however, until about 1829-30, when the substitution of iron for wood in the construction of vessels had passed beyond the experimental stage. In those years the firm of John Laird of Birkenhead began the building of practical iron vessels, and he was followed soon by Sir William Fairbairn at Manchester, and Randolph, Elder & Co., and the Fairfield Works on the Clyde.

The advantage of iron over wood in strength, and in power to withstand tremendous shocks, was early illustrated in the Great Britain built about 1844, the first large, successful, seagoing vessel constructed. Not long thereafter this same vessel lay helpless upon the coast of Ireland, driven there by a great storm, and beaten by the tremendous waves of the Atlantic with a force that would have in a few hours or days broken up and pulverised a “ship of boards,” and yet the Great Britain lay there several weeks, was finally brought off, and again restored to successful service.

Wood and iron both have their peculiar advantages and disadvantages. Wood is not only lighter, but easily procured and worked, and cheaper, in many small and private ship-yards where an iron frame and parts would be difficult and expensive to produce. It is thought that as to the fouling of ships’ bottoms a wooden hull covered with copper fouls less, and consequently impedes the speed less; that the damage done by shocks or the penetration of shot is not so great or difficult to repair, and that the danger of variation of the compass by reason of local attraction of the metal is less.

But the advantages of iron and steel far outnumber those of wood. Its strength, its adaptability for all sizes and forms and lines, its increased cheapness, its resistance to shot penetration, its durability, and now its easy procurement, constitute qualities which have established iron ship-building as a great new and modern art. In this modern revolution in iron-clad ships, their adaptation to naval warfare was due to the genius of John Ericsson, and dates practically from the celebrated battle between the iron-clads the Merrimac and the Monitor in Hampton Roads on the Virginia coast in the Civil war in America in April, 1862.

Although the tendency at first in building iron and steel vessels, especially for the navy, was towards an entire metal structure, later experience resulted in a more composite style, using wood in some parts, where found best adapted by its capacity of lightness, non-absorption of heat and less electrical conductivity, etc., and at the same time protecting such interior portions by an iron shell or frame-work.