EIGHTEENTH CENTURY SCIENTISTS

Press, Volume CX, Issue 32430, 17 October 1970, Page 10

EIGHTEENTH CENTURY SCIENTISTS

Partners In Science. Letters of James Watt and Joseph Black. Edited with introduction and notes by Eric Robinson and Douglas McKie. Constable. 502 pp. Index. This book contains the correspondence of two of the eighteenth century’s most gifted meh of science: James Watt, instrument-maker and engineer, and Joseph Black, less well-known today, but in his time the greatest chemist in Europe, and the discoverer of specific and latent heats. Their letters, written in the latter part of the century, give one a very good idea of the scientific activities which were going on at that time; and Watt’s, in particular, show the remarkable range of his interests. Watt was a largely self-taught man with a gift for mastering any branch of scientific knowledge to which he applied himself. His friend, Professor Robison of Edinburgh University, relates in a Memorial of 1796 how Watt, without previously knowing one musical note from another, contrived to build a small organ containing a number of novel technical devices and tuned to the satisfaction of some of the country’s leading performers; and his own letters contain many references to his virtuosity and restless spirit of inquiry. In one letter, for example, he discusses the merits of coals and cokes in the burning of earthenware; in another he records his experiments with artificial alabaster, or enquiries after a liquor said to bleach brown

linen white in one minute; and he tells of an apparatus he has made for preparing and collecting artificial airs for medicinal purposes. Some of these, he says, have been proved beneficial, but he admits ruefully that "to myself they have been of no avail in any of my complaints.” In other letters we read of his invention of a copying machine, Watt’s interest in manufacturing alkali from salt, and his plans for canals and harbour improvements. He describes, too, how in 1765, he perceived in a flash of insight an efficient method of reducing the excessive consumption of fuel in steam engines. It was a discovery which was to bring him considerable fame and wealth, but, as his letters show, much of his later life was. clouded by legal disputes with unscrupulous firms which attempted to enroach on his patent. The vexation of these wrangles, he writes, “contributed much to impair my faculties of mind, and to destroy that cheerfulness so necessary to happiness.” Nevertheless, by the year 1799, Watt’s defence of his patents had been so successful that Black was earnestly advising him to “enjoy relaxation from business and the amusements which are most suited to your taste, but above all relaxation and ease and gentle exercise and change of air. You need not be anxious now about your fortune. It is already abundant, and it will increase constantly even while you are sleeping.” Throughout the exchange of letters,

one can detect in a dozen small ways the warm affection these men had for each other. Watt, although not a well man himself, is frequently enquiring anxiously after his friend’s health, and urging him to come to stay with him; and he is quick to come to his defence when Black’s discovery of latent heats is questioned by a Spaniard who wishes to give the laurels to a candidate of his own. For his part, Black, who was the more demonstrative of the two, gives a touching expression of his regard when he writes: “There is nothing I meet with now that gives me so much pleasure as your letters.” There are also included letters by John Robison, of the University of Edinburgh, who was a faithful friend of both Watt and Black, and the complete text of Watt’s notebook on his experiments on heat.