Page:Science vol. 5.djvu/400

 general preMnlalion of theory and fact than any work we hAvo aeen. The vnlue ot the winds as the chief motive force, and Ihe inefScacy ot gravity bronght into play by changea of temperature, are clearly inailc out, bo (ar as surface-currentB are con- cerned. The part playeil by the deflective forces coming from the eanh'a roiation is also well staled. So long «i.t the surface-waters are brushed along by the wind in any given direction, l1is tendency to depart from this direction U practically overcome by the wind Itself; but, wbenever the waters set in notion by the wind enter a re^on ot calm, they at once b^in to describe the 'inertia curve,' — a line whose radius of curvalure. decreases with the sine of the lalilude. Already in latitude 5°, this radius of curvature for a velocity of one metre a second is only forty-two and a half naiLllcal mllits: hence, whan the Simlh-Atianllc current runs into the region of eaima Just north of the equator, its waters will quickly turn to the riglit, easily falling Into the power of the south-west monsoon of that region, and so forming the Guinea current, and. during the northern dimmer, the equatorial counter-current as well. Tbe author therefore concludes, that, after the winds and the configuration of the coasts, the diurnal rotnlion of the earth must tie recogtilzed as the most Important factor in determining the existing syuteoi of ocean- currents,

— Messrs. Sampson Low & Co. of London an- nounce ' Under llie rays of the aurora bo real is, in the land of the Lapps and Kcaeu?," — an original work by Dr. Sophus TromUott, edited by Mr. Carl Sicwers. The hook contains an account of the work of the recent circHmpolar scientific eipeditions, and an ex- position of our present knowiedae of the aurora borealls, to the study of which the author has de- voted the greater part of his life.

— The second session of the summer course of bot- any at McGlll college, Montreal, will be opened to ladies on Tuesday, May D. The course, which will be In chai^ of Professor Penhallow, will continue tor seven weeks. It Is designed toiiive practical Instruc- tion in general morphology, including the analysis and study of Canadian plants as found in the vicinity of Montreal. Instruction will also be given In his- tology with the microscope.

— In the annual report for 1384, ot Prof. G. H.. Cook, state geologist ot New Jersey, Itiere is a de- scription of some remarkable recent changes in the condition of the land near South Amboy. A forest of common limber, such as oak and cliesmut, stand- ing on land ten or twelve feet above higli-water mark, was cut down, and the underlying sands to a depth ol twelve feet were stripped off preparatory to [aking out the stoneware clays below; but, before reaching the latter, a swamp deposit a few feet thick, with wbile-ceilartrces embedded in It. was passed through; and at the bottom of this, standing in the clay, were several oak stumps, at a level two feet below the adjacent salt-marsh, which is overflowed by high tides; and near Ihe stumps there was a log aliout a foot In diameter, eight or ten feet long, that had been cut with an axe. There Is ao tradition telling uf the

��burial of this forest, but it must have been less than two hundred and eighty years ago. The successlva deposits are well shown In the excavation. Tbe clay at the bottom; the old oak fr<rest In the soil on this clay; then the blnck swamp- earth, and its small cedars embedded therein; Anally the overlying plain of sand and gravel, with its late growth ot upland timber, — with this there is good evidence that the ground, which was formerlj^ high enough above the level of the sea to sustain a growth of upland tlmlwr, is now BO low that every tide could cover It with salt water. Some valuable figures are given in illustration ot the superposition of glacial drift on unconsolidated tertiary clays, and of the columnar trap-rocks and waler-lwaring sands. The Green-Pond Mountain rocks, which were thought trlnsilc by Rogers, and which were regarded asPolsdam In Ihe earlier reports of the present survey, are now placed In the middle Devonian. The crystalline rocks of the Highlands, which have been called Laurentlan on the strength ot their litbolriglcal characters, are here prudently called simply arcliaean. In the ali^ience of sufficient, evidence to correlate and Uleniify them.

— Major. -Gen. Sir F. J. Goldsmid has an artlcl in the April number of the Contemporary reniew Ru<sla and the Afghan frontier. The ^' article is, that the apathy will) which the Bngllf government and people have hitherto watched Russian advance frora the Caspian towards India due to a lamentable Ignorance, on their part, of geographf and topography of central Asia, This undoubtedly true; but how far the remedy propo- by the gallant general would be a remedy, gether dllTerent matter.

— The Royal medals of the Royal geograpbii society, says Nature, this year were awarded to Joseph Thomson and Mr. H. E. O'Neill; U> former for his welt-known work in Africa, am the latter for his Ihlrteen journeys of exploratli along the coast and in the interior of Uoaamblqi The Murchison grant for 1885 was awarded to Pandit Krenhna (or his four explorations made wl attached to the survey of India, and especially ft his extensive and Important Journey in the interior i Tibet. The Back grant went to Mr. W. O, Hodkini for his Australian explorations, and the Cnthbei Peek grant to Mr. J. T. Last tor Ills surveys and ethnological researches in the southern Masai. Nguru, and [>ther neighboring countries. The following were made honorary corresponding raembars: Chief- Justice Daly, president of the geographical society of New York; Mr. Elisi^ Reclus, the eminent geogra- pher; and Herr Moritz von DSchy. the dUtingulahed Austrian explorer of the Sikkim Himalayas, the Cau- casus, and oiher r^ons.

— On the night of the 5th of April, the ste«roship Nurnberg, in latitude 40° north, longitude IS° 30* west, during a very heavy storm from west-north- west, bad msst-heads and yard-arms lighted ivllh St. Elmo's lights. It was raining and hailing at the time, and the barometer showed 29.10. A hall of lire ex- ploded during the storm, with a loud noise, simlliu' to the explosion of a gun.

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