The American Journal of Science, Volume 181

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J.D. & E.S. Dana, 1911 - Earth sciences

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Page 578 - The Sun's rim dips; the stars rush out: At one stride comes the dark; With far-heard whisper, o'er the sea, Off shot the spectre-bark.
Page 102 - We hence learn that in the evolution of the continental germ, after the appearance of the Azoic nucleus, there were two prominent lines of development ; one along the Appalachian region, the other along the Rocky Mountain region — one, therefore, parallel with either ocean. Landward, beyond each of these developing areas, there was a great trough or channel of deeper ocean waters, separating either from the Azoic area.
Page 490 - Since Ettingshausen's announcement a dozen or more fossil species have been described. The oldest known European form occurs in the upper Eocene or lower Oligocene (Ligurien) of France and the species become increasingly abundant throughout southern Europe especially toward the close of the Oligocene and the dawn of the Miocene, Saporta stating that the slabs from the leaf-beds at Armissan in southeastern France are thickly strewn with their peculiar fruits. Fossil forms continue in Europe throughout...
Page 490 - ... geological history. Engelhardtia proves to be another illustration of this principle, for its peculiar three-winged fruits have been known in the fossil state for almost a century. They were long unrecognized, however, and the earlier students who described them compared them with the somewhat similar winged fruits of the genus Carpinus (Betulaceae).
Page 489 - A single little known species rarely represented in even the larger herbaria occurs in Central America and is the type and only species of the genus Oreomunnea of Oersted. This is much more restricted in its range than are its kin beyond the Pacific. Oreomunnea is very close to Engelhardtia, and for the purposes of the paleobotanist the two may be considered as identical since they represent the but slightly modified descendants of a common ancestry which was of cosmopolitan distribution during the...
Page 87 - S carrying the slit and be prolonged further toward the rear to carry the flame or Geissler tube apparatus. The table tt is revoluble on a brass rod fitting within the gas pipe, which has been slotted across so that the conical nut M may hold it firmly. The axis passes through the middle of the grating, which is fastened centrally to the table tt with the usual tripod adjustment.
Page 569 - The fact that an ion has been caught, and the exact instant at which the event happened is signalled to the observer by the change in the speed of the droplet under the influence of the field. From the sign and magnitude of this change in speed, taken in connection with the constant speed under gravity, the sign and the exact value of the charge carried by the captured ion are determined. The error in a single observation need not exceed one third of one per cent.
Page 468 - The bowlder was split along the plane in which the fossil lies and part of the bones are in one half and part in the other. These bones are hollow and the whole framework is very light and delicate.
Page 499 - ... high temperatures and pressures on certain systems and reactions, and especially those in which water plays an important part. The work has progressed until now we are able to introduce into the bomb current leads and thermo-element wires in such a manner that the wires are all thoroughly insulated electrically, and the joint remains absolutely pressure-tight. Thus, it is possible to heat a substance to somewhat over 400, under pressures up to 2,000 atmospheres, and to measure both temperature...