4 8 4 



NA TURE 



[.Sept 



industries. Every success that is achieved by the mosl 



itional productions creates a demand for still further 

 ; and in meeting these demands, in the future, the race 

 will be to the swift and the battle to the strong. The speed 

 and the strength that you require in order to enable you to hold 

 your own in this contest are speed and strength of intellect. In 

 rds, you require your intelligence to be cultivated and 

 well informed, and to be made prompt and active, by means oi 



culture ; and it is necessary for you to acquii 

 firm and comprehensive grasp of sound theoretical principles as 

 will enable you to rely safely upon your own powers of judg- 

 ment, and to act in difficult cases with certainty and precision. 

 Not only does modern competition ever demand more from you 

 in the way of technical knowledge, skill, and resource, but it 

 also shortens the lime at your disposal for supplying it. The 

 huge and complicated engineering structures of the present day, 

 such a^ are constructed in this district, have to be completed 

 in as short a time as the much simpler and smaller ones of a 

 generation ago. You have thus not only much more to think 

 about in building a ship, and problems of greater number and 

 difficulty to solve than used to be the case, but you have only 

 th ■ tin e in whii h to do it all. You cannot afford to delay 

 the progress of construction for the purpose of trying 

 ments or brooding over any difficulties you may meet with. (l 



try to decide promptly each question 

 you have to qualify yourselves fur doing that. The naval archi- 

 tect and engineer of the present day requires to supplement his 

 practii il knowledge by a close and systematic study of various 

 branches of science. An enumeration of some of the chief of 

 them will be sufficient to show how great are the demands thus 

 made upon him. There are the laws upon which the flotation 

 and stability of ships, and their behaviour among waves, depend ; 

 those which determine the structural strength of a ressi 

 its relation to the forces which may be brought to bear upon her 

 by her own weight and that of her cargo, when she is floating 

 upon a changing wave-surface ; the difficult problems connected 

 with the resistance of a ship to motion through the water, the 

 power requisite to drive her at a given speed, and the manner in 

 which this is affected by her outward form and proportions. Then 

 there is the wide field of thermal science, and its application to 

 the means by which the conversion of heat into mechanical work 

 is effected through the agencies of the boilers, cylinders, con- 

 rid mechanism of the engines ; together with the action 

 of the propeller, and the principles upon which its efficiency 

 depends. No man has ever yet succeeded in completely master- 

 ing these difficult and complicated problems ; and it is perhaps 

 not possible for many of you to advance very far towards their 

 solution. Still it must be borne in mind that it is only by 

 studying the sciences which bear upon them that any real or 

 substantial progress can be effected ; and although finality may 

 be unattainable, great advances are possible, and are constantly 

 being made. Hardly a year passes without something consider- 

 able being done to improve our knowledge of those natural laws 

 upon which the safety and efficiency of ships at sea depend. 

 There is probably no district in this country which has benefited 

 more in the past than Govan by scientific progress and great 

 mechanical skill in shipbuilding and engineering, or whose pros- 

 perity in the future is more dependent upon it. Govan has been 

 placed among the foremost of shipbuilding communities by 

 means of great scientific and practical talent, industry, and 

 enterprise ; and it rests with many whom I now see before me 

 to maintain it in the honourable and distinguished position to 

 which it has been raised. The names of Napier and Elder, not 

 to mention others, are alone sufficient to give prestige to any 

 engineering locality ; and they insure for Govan a high place in 

 all future records of scientific, mechanical, and industrial pro- 

 gress. Upon you rests the responsibility of worthily walking in 

 the footsteps of those and others among your distinguished men, 

 and of striving to keep erect in this district the noble edifice 

 they have reared." 



SOCIETIES AND ACADEMIES 



taris 



Academy of Sciences, September I. — M. Rolland, Pre- 

 sident, in the chair. — Some remarks on the subject of the theory 

 of the figure of the planets, by M. F. Tisserand. The author's 

 calculations and estimates of their present form are based on the 

 assumption that the celestial bodies were originally in the fluid 

 state, subject only to the mutual attraction of their constituent 



elements, and endowed with a rotatory movement with very 

 slight angular velocity. Their outer surface would thus be some- 

 what that of a revolving ellipsoid. — Researches on the general 

 development of vegetation in an annual plant : functions of the 

 hydrocarbon elements, by MM. Berthelot and Andre. — Note on 

 the general resolution of the linear equation in matrices of any 

 order, by Prof. Sylvester. — Remarks on the attempts made at 

 various times to solve the problem of aerial navigation, by M. 

 Laussedat. The author supplies a rapid sketch of the progress 

 of aerostatics in connection with the Commission lately appointed 

 by the Academy to examine the claims of priority of various 

 inventors. He considers that General Mcusnier was the first to 

 introduce the elongated shape of the balloon, the sen s is the pro- 

 pelling agent, and the principle of the " ballonnet " or air-bag, re- 

 discovered by M. Dupuy de Lome. M. Conte is credited with 

 great improvements in the construction of spherical balloons, and 

 M. Alcan is stated to have anticipated M. II. Giffard by several 

 years in the application of steam to aerial navigation. — Compari- 

 son between the coloured electro-chemical and thermal rings of 

 Nobili and others, by M. C. Decharme. — Observations of the 

 planet 240 discovered at the Observatory of Marseilles on 

 August 27, 1SS4, by M. Borrelly. — Determination of the wave- 

 : the chief rays and bands of the infra-red solar spec- 

 trum, by M. Henri Becquerel. Tabulated results are given for 

 the chief bands in millionths of millimetres. — Remarks on the 

 and development of the nervous cellules in the spinal 

 marrow of mammals, by M. W. Vignal. — Note on the recent 

 luminous phenomena observed around the sun in Switzerland 

 (second communication), by M. F. A. Forel. A second trip to 

 the Alps, undertaken towards the end of August, enables the 

 author to confirm and complete the details already communi- 

 cated to the Academy. Aeronauts are invited to study some of 

 these light-effects, and especially the red corona round the sun, _ 

 scarcely perceptible from the plains and low elevations, but per- 

 fectly visible at altitudes of from 3000 to 6000 feet above the 

 sea-level. — Account of the optical telegraph recently established 

 between the islands of Mauritius and Reunion, by M. Bridet. 

 The telegraph set up on Lacroix Peak in Reunion and Vert 

 Teak in Mauritius was completed on the night of July 12-13, 

 when messages were freely exchanged between the two island-. 



CONTENTS page 



Descriptive Mineralogy 461 



The Mosses of North America. ByJ. G. Baker, F.R.S. 461 

 Letters to the Editor : — 



The Diffusion of Species. — The Duke of Argyll . . 462 

 Meteor- Moon- and [Sun-Shine. — Prof. C. ^Piazzi 



Smyth, Astronomer-Royal for Scotland ." . . . 462 



Pons' Comet — Pink Glow. — A. S. Atkinson . . . 463 



Alternation of Generations in Salpa. — R.N.Goodman 463 



Forked Lightning. — Rev. Dr. C. Michie Smith . 463 



Sun-Glows. — Robert Leslie 463 



Fireballs. — Wm. White 464 



Deep-Sea Corals. —Prof. P. Martin Duncan, F.R.S. 464 



Iridescent Lunar Halos. — T. H. Potts 464 



Sextants. — T. W. Baker 464 



Electrical Rainbow.— R. S. Newall, F.R.S. . . 464 



Rainbow on Spray. — G. H 464 



Circular Rainbow seen from a Hill-lop. -— W. L. 



Goodwin 465 



Intelligence in Frogs.— B. W. S 465 



The Temperature of the Solar Surface. By Capt. J. 



Ericsson. (Illustrated) 465 



The British Association : — 



Section E — Geography — Opening Address by General 



Sir J. H. Lefroy, R. A. , C. B. , K. C. M. G. , F. R. S., 



F.S.A., V.P.R.G.S., President of the Section . 469 



Section G — Mechanical Science — Opening Address by 



Sir F. J. Bramwell, F.R.S., V.P.Inst.C.E., 



President of the Section 472 



Notes 47 6 



Geographical Notes 47S 



Our Astronomical Column : — 



Variable Stars 479 



Comet 1884^ (Barnard) 479 



The Movements of the Eaith, VI. By J. Norman 



Lockyer, F.R.S. (Illustrated) 480 



The French Association for the Progress of Science 483 



Training in Naval Architecture. By Prof. Elgar . 483 



Societies and Academies 484 



