successful. When turn of the tide came, as it did, miners were enabled to benefit by it probably some months sooner than otherwise might have been possible. Yet cases in which a policy of restricted production can be of general benefit to society are not numerous. They can occur only when production has been lopsided and when demand for certain commodities has declined while production has been sustained until accumulated stocks become excessive.

Through the interest of Glasgow capitalists in chemical industries, originating in the latter part of the eighteenth century and extending greatly in the nineteenth century, reduction of copper ores had become a great industry. Copper was imported chiefly from Spain, where it was exploited mainly by Scots capital. This industry led to development of a group of metallurgical chemists in Glasgow who devoted themselves to improvement of processes for extraction of metals. Their investigations, though primarily concerned with copper, were naturally not confined to that metal. In the early eighties attention was widely drawn to extraction of gold from inferior ores through exploitation of the Transvaal mines. It was found that by means of then existing methods of extraction a large amount of gold in the aggregate was left in the ore because its extraction did not pay. Several new processes for extraction of gold from inferior ores were brought forward in obedience to obvious demand. In developing these processes, Glasgow metallurgical chemists took a principal share. One of my friends, J. D. Macarthur, mentioned to me that he had some ideas on the subject, and I encouraged him to set them out in a paper. I was able to arrange for publication of this paper in a technical journal, and it immediately attracted the attention of a group of capitalists who had been induced to embark in another process and had been disappointed in the results of experiments they had conducted. They made an arrangement with Mr. Macarthur, the ultimate result of which was development of the Macarthur-Forest or cyanide process for extraction of gold which wholly revolutionised the industry. This process undoubtedly contributed to immensely increased production of gold which began to take effect in the late eighties.

I cannot in this place undertake to sustain the thesis that the increase in production of gold was the most important single factor in stimulation of industrial activity which put an end to the trade malaise. It needs, however, no argument to show that had this increase not taken place, a series of hazardous experiments in currency must have been forced upon commercial nations.

In the perspective of forty years, the conspicuous feature in econo

mic development, especially within the ten years 1881-90, is growth of speed. Transport had to be organised for increasing quantities, and the most economical systems of transport had to be devised because of depression of prices. Concentration of population in industrial areas induced new methods of local transport. Mechanical began to supersede animal traction-the urban tramways introduced in the preceding decade were improved-cable and electrical power took the place of horses, and vicinal railways intensified in many regions facilities for local communication. Passenger trains became faster and steamships were fitted with engines of greater power. The struggle between iron wheel and propeller commenced. About 1881 the Age of Speed may be said to have had its effective beginning.

Greater speed meant evolution in industrial technique, and in this evolution the Clyde took an important share; for it was on this river that the marine engine had not only its birth, but its adolescence and even its maturity. The triple-expansion engine was followed by the quadruple- and quintuple-expansion engine on the Clyde during this period.

Another scarcely less important contribution was adaptation to the mercantile marine of principles of naval design emerging from experiments of Mr. Henry Froude at Haslam. On the Clyde Messrs. Denny began the use of the experimental tank, and Lord Kelvin developed the theory of waves, which together led to improvements in design. So also the interior combustion engine was advanced a stage by Mr. Dugald Clerk, whose gas engine was one of the products of this time. Although the results of his investigations and experiments were not published until after the close of the period, the application of electrical propulsion to vessels by my brother Henry A. Mavor 2 may be said to belong essentially to the same epoch of scientific activity.

Thus during this period, the greater part of which was characterised by stagnation in trade, there seemed to arise the leisure necessary to prepare the way for further progress.

This leisure arising from absence of demand for immediate production on a large scale, and utilisation of the leisure by assiduous brains, resulted in gradual organisation of those mighty combinations of mechanism controlled by science, and of industry exercised by

My brother, Ivan Ingram Mavor, who had been an apprentice with the Fairfield Shipbuilding Co., was employed by Messrs. Denny in connection with these experiments. He afterwards became outside manager of Armstrong, Mitchell and Co.'s Low Walker Yard, and later manager of Hawthorne, Leslie and Co.'s Yard at Yarrow-on-Tyne. He was killed at Liverpool in 1886.

'Henry Alexander Mavor died in 1915.

skilful hands that we know as shipbuilding yards and marine engineering shops. It was by no accident of fortune that the Clyde became by far the greatest shipbuilding river in the world. Miles of shipyards and formidable clangour of power rivetters are feebly described by any such word as titanic. The collective energy of brain and muscle is yet to be expressed in some fitting phrase.

Among great engineering works in the field of transport, carried out in Scotland in the eighties, the Forth Bridge is pre-eminent. Designed by two Englishmen, Sir John Fowler and Sir Benjamin Baker, this notable work was executed by a Glasgow man, Sir William Arrol. It was my good fortune to know well all of these remarkable men. I visited the bridge at frequent intervals during its construction from beginning to end. I went down into the caissons upon which the piers are built before they were put into position, and I often went up to tops of the towers and to ends of the great cantilevers while they were being constructed. On one occasion I followed Sir John Fowler, then about seventy years of age, hand over hand, up a ladder of three hundred feet to the top of the north tower of one of the cantilevers; and many times I went over the works with Sir Benjamin Baker and Sir William Arrol.1

Some of the American engineers of the time derided the immense factor of safety which was involved in the design; but time had its revenge. One of the most scornful of these critics designed an important bridge which collapsed with great loss of life. The report of the investigating engineers showed that an insufficient margin of safety had been provided in the design. The conditions under which the Forth Bridge was built demanded even an excessive margin. The Tay Bridge had collapsed and its deficiency in respect to margin of safety had been demonstrated. Public confidence in great bridges would have been destroyed by another disaster. Therefore the utmost precautions had to be taken to build a bridge that should withstand any strain to which it could possibly be subjected. Elaborate and very interesting experiments were made on wind pressure at the site of the bridge; and every other problem of a complicated series was grappled with in the same thoroughgoing manner.

A great deal of nonsense has been written upon alleged deficiencies of Great Britain in technical education.2 Those who were actually

My brother, Alfred E. Mavor (died 1921), was engineer in charge of the extensive installation of electric light at the construction works.

I am sorry to say that one of the offenders in this respect is my friend Dr. H. B. Gray, formerly Headmaster of Bradfield. His book Eclipse or Empire? seems to me to present the case for technical education with gross exaggeration.