338 



NATURE 



\_Au%ust 9, 1883 



it that the existing hammers were incapable of forging a 

 wrought-iron shaft of thirty inches diameter? Simply 

 because of their want of compass, of range and fall, as 

 well as of their want of power of blow. A few moments' 

 rapid thought satisfied me that it was by our rigidly 

 adhering to the old traditional form of a smith's hand 

 hammer — of which the forge and tilt hammer, although 

 driven by water or steam power, were mere enlarged 

 modifications — that the difficulty had arisen ; as, whenever 

 the largest forge hammer was tilted up to its full height, 

 its range was so small that when a piece of work of con- 

 siderable size was placed on the anvil, the hammer 

 became ' gagged ' ; so that, when the forging required the 

 most powerful blow, it received next to no blow at all, as 

 the clear space for the fall of the hammer was almost 

 entirely occupied by the work on the anvil. 



" The obvious remedy was to contrive some method by 

 •ubich a ponderous block of iron should be lifted to a 

 sufficient height above the object on which it was desired 

 to strike a blow, and then to let the block full down upon 

 the forging, guiding it in its descent by such simple means 

 as should give the required precision in the percussive 

 action of the falling mass. Following up this idea, I got 

 out my ' Scheme Book,' on the pages of which I gene- 

 rally thought on/, with the aid of pen and pencil, such 

 mechanical adaptations as I had conceived in my mind, 

 and was thereby enabled to render them visible. I then 

 rapidly sketched out my Steam Hammer, having it all 

 clearly before me in my mind's eye. In little more than 

 half an hour after receiving Mr. Humphries' letter 

 narrating its unlooked-for difficulty, I had the whole con- 

 trivance, in all its executant details, before me in a page 

 of my Scheme Book, a reduced photographed copy of 

 which I append to this description. The date of this first 

 drawing was the 24th November, 1839." 



The paddle-wheel of the Great Britain was, however, 

 never forged, as about that time the substitution of the 

 screw for the paddle-wheel as a means of propulsion was 

 attracting much attention. Indeed, Mr. Nasmyth could 

 get no English firm to take up his invention, and was 

 naturally surprised to find, on a visit he made to France 

 in 1842, that his steam-hammer was in full operation at 

 Creuzot, M. Schneider having copied the design from Mr. 

 Nasmyth's drawing when on a visit to Patricroft. Very 

 naturally Mr. Nasmyth on his return to England lost no 

 time in protecting his invention by patent ; its career 

 since is well known. 



As we said, Mr. Nasmyth retired from business in 

 1856, twenty-eight years ago, bought a " Cottage "in Kent, 

 a picturesque place near Penshurst, to which he gave the 

 characteristic name of Hammerfield. Long before this 

 he had learned to take an interest in science, especially in 

 geology and astronomy. His investigations into the 

 structure of the moon are well known, and these, as well 

 as his examinations of the sun's surface, have been con- 

 ducted with telescopes of his own construction. His 

 elaborate work on the moon, with its magnificent series 

 of views of its surface, has long been classical, and his 

 contributions to the subject of the sun's heat are well 

 known. His imagination, when not engaged in devising 

 mechanical contrivances and contributing to scientific 

 theory, has often blossomed into fancy which has found 

 expression in exquisite pictures of fairy-land and other 

 regions of the unseen. Altogether Mr. Nasmyth's long 

 life has been one of almost unchequered success ; from 

 the first he has clearly seen what he wished to accom- 

 plish, and with scientific precision has devised the most 

 effective means of realising his aims. Not the least 



delightful and instructive of his many works is the one 

 before us, which we commend to the study of all young 

 engineers, as well as to all who wish to read the story of 

 a successful life simply and pleasantly told. 



John Duncan's career, as told by Mr. Jolly, is a com- 

 plete contrast to that of Mr. Nasmyth. He never rose 

 above the humble station in which he was born, nor 

 apparently ever wished to do so. He had all along to 

 struggle for a bare living, and was essentially unpractical. 

 What little education he had was self-acquired, and it 

 was never much so far as book-learning goes. His love 

 of flowers was a passion. He amid many discourage- 

 ments managed to acquire a mastery of systematic 

 botany, and his collection of Scottish plants, now in the 

 possession of Aberdeen University, is of real value. Every 

 moment he could spare was devoted to adding to his 

 collection, and partly as weaver and partly as harvester 

 he traversed most of his native land. In other respects 

 he was a man of superior mind, though in no sense a 

 genius, and by no means to be compared with Robert 

 Dick or even Thomas Edward. Mr. Jolly has narrated 

 in our own columns the main facts of Duncan's career. 

 Had he been more happily situated he would certainly 

 have done real service to science. It is some consolation 

 to think that his merits were recognised before he died, 

 and that his last days were surrounded with comforts and 

 attentions to which throughout his previous life he had 

 been a stranger. As we have said, Mr. Jolly has made 

 too big a book of the materials he has collected, and 

 although it abounds in interest, it would have been more 

 creditable to his literary skill had he taken the trouble to 

 rid it of redundancies. 



THE HE A VENL V BODIES 



The Heavenly Bodies; their Nature and Habitability, 

 By W. Miller, S.S.C. Edinburgh, Author of "Wintering 

 in the Riviera." Pp. 347. (London : Hodder and 

 Stoughton, 1883.) 



FEW subjects could be mentioned more remote from 

 the common interests and pursuits of life than 

 what has been usually called the " plurality of worlds," an 

 expression now so long restricted to one well-ascertained 

 meaning as to have lost any ambiguity that might have 

 been charged upon it. The question is one of mere 

 curiosity, and leads to no direct result ; but it has always 

 carried with it an attraction irrespective of its unpractical 

 nature, and has exercised the ingenuity of so many minds 

 that its literature is of no inconsiderable extent. To this 

 the book now in our hands is the most recent contri- 

 bution. It is not the work of an astronomer, as the 

 author himself has informed us ; but as his profession 

 leads him to the examination of evidence this need not 

 be considered a material disadvantage. His position, 

 however, in this respect would have been improved by a 

 little more care in the collection of his data, which in 

 some instances, such as Midler's "central sun," the 

 satellites of Uranus and Neptune, the polar flattening of 

 Mars, and the observations of Schiaparelli, are somewhat 

 in arrear ; and it may be the case that those more inti- 

 mately conversant with the subject would estimate the 



