192 



NATURE 



{June 21, 1888 



be made in Regnault's determinations of the weight of a 

 litre of the elementary gases, by M. J. M. Crafts. The 

 error already pointed out by Lord Rayleigh is here corrected 

 for air, N, H, O, and C0 2 . — Experiments with a non-oscillating 

 pendulum, by M. A. Boillot. It is shown that the oscillating 

 pendulum, which in Foucault's experiment demonstrates the 

 movement of the globe, may be used for the same dsmonstration 

 by suppressing the oscillatory action and operating in a room. — 

 Measurement of the velocity of etherification by means of electric 

 conductors, by M. Negreano. A process is explained for measur- 

 ing the rapidity of the chemical reactions which take place 

 between certain resisting bodies at the moment their electric 

 resistances become varied. These resistances have been measured 

 according *-o the method indicated by Lippmann. — On a diamanti- 

 ferous meteorite, which fell on September 10/22, 1886, at Novo- 

 Urei, in the Government of Penza, Russia, by MM. Ierofeieff 

 and Latchinoff. Analysis of this specimen, weighing 1762 gr., 

 shows that it contains 1 per cent, of very fine carbonado, or 

 diamond dust, besides 1 "26 of amorphous carbon. The other 

 chief substances were — peridot, 6"]'4J&; pyroxene, 23*82; and 

 nickled iron, 5 "45. 



Berlin. 



Physical Society, June 1. — Prof, von Helmholtz, President, 

 in the chair. — Dr. Lummer gave an account of experiments which 

 he had made on the determination of the focal length of lenses 

 by the method of Abbe in Jena. The method is based upon the 



equation/ = 



; where /"is the focal length, a the distance 



of two objects from the lens, and /3 X ft 2 the respective magnifica- 

 tions of their images. The speaker discussed first the way by 

 which Abbe had arrived at the above equation, and then went 

 thoroughly into an explanation of the methods for measuring the 

 amount of magnification of the images. It must suffice here to 

 say briefly that the magnification was measured by a microscope 

 directed along the principal axis of the lens, and at right angles 

 to its surface, the microscope then being moved backwards and 

 forwards, until the upper and lower ends of the image were 

 visible. Prof, von Helmholtz explained that during his physio- 

 logical-optical researches he had already determined the focal 

 lengths of lenses by the measurements of the magnification, in 

 accordance with the formula given above, admitting at the same 

 time that his methods were perhaps less exact. — Dr. Lummer 

 then gave an abstract of a paper on the movement of air in the 

 atmosphere, which he had recently read before the Academy of 

 Sciences. In solving the problem, he had made use of the 

 principle of mechanical similarities. When the hydrodynamic 

 equation for a given motion is known, it is only necessary to 

 multiply all the factors by n in order to represent the motion in 

 much larger dimensions. Accordingly if the conditions of the 

 occurrence of air currents, such as take place in the atmosphere, 

 have been experimentally determined in the laboratory for 1 

 cubic metre of air, and if the atmosphere is assumed to be 8000 

 metres high, then the space, time, and moment must be 

 multiplied by 8000, while on the other hand the internal friction 

 must be taken as being only 1/8000 of that which has been 

 determined by experiment. It follows from this that the 

 internal friction is of very small account ; but as against this, the 

 friction of the earth's surface has a considerable influence and 

 cannot be neglected. Supposing a mass of air moving horizon- 

 tally is considered, then a series of particles* of air, which were at 

 the outset vertically each above the other, will finally place them- 

 selves along a curve of sines as the result of friction at the earth's 

 surface. Calculation shows that it would require a period of 

 42,000 years before the motion was reduced to one-half as the 

 result of internal friction. The speaker then considered the atmo- 

 sphere as made up of rings of air which surround the earth in 

 coincidence with the parallels of latitude : each of these rings of 

 air has its own moment of rotation, which depends on its radius, 

 and is therefore greatest at the equator and least at the poles. 

 If the air which is streaming upwards at the equator were to 

 stream down again to the earth in higher latitudes, it would be 

 moving with a velocity far exceeding that of any known storm, 

 even at the latitude of 30 . Since the internal friction of 

 the air is so small that it may be neglected, the speaker 

 proceeded to point out the other factors which have an influence 

 in slowing down the air as it falls. He regards them as being 

 the vortex motions which take place in the atmosphere at the 

 iscontinuous surfaces of two masses of air moving with different 



velocities. These vortex motions cause the adjoining layers of 

 the two masses of air to mix, and thus diminish their velocity. 

 This is the explanation of the calms, trade-winds, sub-tropical 

 rain?, and other phenomena which occur in the atmosphere. It 

 would occupy too much space to give even a brief statement of 

 how these conclusions are arrived at. 



BOOKS, PAMPHLETS, and SERIALS RECEIVED. 



A Course of Practical Instruction in Botany, Part 1, 2nd edition : Prof. F. 

 O. Bower (Macmillan). — Lessons in Elemeniary Mechanics, Stage 2 : W. H. 

 Grieve (Longmans). — Observations on the Embryology of Insects and 

 Arachnids : A. T. Bruce (Baltimore). — Smithsonian Report, 1885, Part 2 

 (Washington). — Birdsnesting and Bird-skinning, 2nd edition : M. Christy 

 (Unwin). — An Elementary Treatise on Mensuration : E. J. Henchie (School 

 Books Publishing Co.) — First Elements of Experimental Geometry : P. Bert ; 

 translated (Cassell). --Introductory Inorganic Analysis : E.H.Cook (Churchill). 

 — Origin and Growth of Religion as illustrated by Celtic Heathendom : Prof. 

 J. Rhys (Williams and Norgate). — Sierra Leone; or the White Man's 

 Grave: G. A. Lethbridge Banbury (Sonnenschein). — Explorations and 

 Adventures in New Guinea : Capt. J. Strachan (Low). — Longmans' School 

 Geography for Australasia : G. G. Chisholm (Longmans). — On the Dicoty linae 

 of the John Day Miocene of North America : E. D. Cope. — On the Mechani- 

 cal Origin of the Dentition of the Amblypoda : E. D. Cope. — The Theory 

 of the Tides: J. Nolan (Dulau). — The Perissodactyla: E. D. Cope (Phila- 

 delphia). — The Mechanical Origin of the Sectorial Teeth of the Carnivora : 

 E. D. Cope (Salem). — Recent Advances in our Knowledge of the Law of 

 Storms : F. Chambers (Bombay). — Causation of Pneumonia : H. B. Baker 

 (Lansing). — Quarterly Journal of the Royal Meteorological Society, ApriJ 

 (Stanford). — Quarterly Weather Report, Part 3 (Eyre and Spottiswoode). — 

 Hourly Readings, 1885 (Eyre and Spottiswoode). — Travaux de la Societe 

 des Naturalistes de St. Pdtersbourg, vol. xix. 1888, Section de Geologie et 

 de Mineralogie (St. Petersbourg). — Notes from the Leyden Museum, vol. x. 

 Nos. 1 and 2 (Brill, Leyden). — Madras Journal of Literature and Science, 

 Session 1887-88 (Madras). — Proceedings of the Academy of Natural Sciences 

 of Philadelphia, Part 1, 1888 (Philadelphia). — Internationales Archiv fur 

 Ethnographie, Band i. Heft 3 (Triibner). 



CONTENTS. page 



The Steam-Engine 169 



The Animal Alkaloids 170 



Practical Forestry 171 



Our Book Shelf :— 



Drummond : " Tropical Africa" 171 



Wormell : " Plotting, or Graphic Mathematics " . . 172 



Gallatly : " The Elements of Logarithms " 172 



Letters to the Editor : — 



Thunderstorms and Lightning Accidents. — H. New- 

 man Lawrence 172 



Nose-Blackening as Preventive of Snow-Blindness. — 



A. J. Duffield 172 



The Lethrus cephalotes. — Arthur E. Shipley ... 172 

 Proposed Fuel-testing Station for London. — Bryan 



Donkin, Jun . 172 



The Geometric Interpretation of Monge's Differential 

 Equation to all Conies — the Sought Found. — 



Prof. Asutosh Mukhopadhyay 173 



Personal Identification and Description. I. {Illus- 

 trated.) By Francis Galton, F.R.S 173 



Soap-Bubbles. {Illustrated.) 177 



The Paris Observatory 179 



The Photographic Chart of the Heavens 180 



The Incurvature of the Winds in Tropical Cyclones. 



By Henry F. Blanford, F.R.S 181 



Notes 182 



Our Astronomical Column : — 



The Constant of Aberratio* 185 



The Markings on Mars 185 



Comet 1888 a (Sawerthal) 186 



Astronomical Phenomena for the Week 1888 



June 24-30 186 



Geographical Notes 186 



Technical Instruction. By Sir Henry Roscoe, M.P., 



F.R.S 186 



The International Geological Congress 188 



University and Educational Intelligence 189 



Scientific Serials 189 



Societies and Academies 190 



Books, Pamphlets, and Serials Received 192 



