1879.1 [Derby. ter and position to those just described, but so far they have yielded no fossils, that will serve for their classification, and they have been referred to the Tertiary solely on account of their stratigraphical position. The only Tertiary fossils known from this region are the fossil leaves of Tonantins, and the fresh and brackish water mollusks of Pebas and other localities in Perú. These, however, occur in lignitiferous beds, quite different from those now under consideration, and the relation between the two has never so far as I am aware, been satisfactorily determined. The only division that can at present be made in the region of the Lower Amazonas, is between the beds of the high table-lands, and those of the lower plains about Pará and eastern Marajó. These last, consisting of abrupt alternations of coarse and fine sandstone, generally ferruginous, along with colored clays, are certainly more modern than the former, and belong to the later Tertiary or the Quarternary. During the deposition of the Tertiary, there were considerable movements of depression and subsequently of elevation, but these movements were, as far as is known at present, unaccompanied by disturbances of the strata or eruptions of igneous rocks. After the elevation of the Tertiary table-lands, began the alluvial deposits of the varzea. They consist, according to circumstances and localities, of sands or clays, or a mixture of the two, a yellowish structureless clay predominating, often having above it a bed of black clay, impregnated with vegetable matter. Part of this deposit was without doubt formed in an estuary, while the river was taking possession of the bed prepared for it ; but it is now impossible to distinguish the estuary deposits from those that are purely fluvial. The proofs of the estuary condition are not so much in the characters of the deposits, as in the form of the tributary valleys, which are widened in a manner that can only be explained by the action of the tides. With the formation of the varzea, the geological evolution of the valley of the Amazonas terminated. We cannot in this place enter into a consideration of the interesting phenomena, illustrative of Geology and Physical Geography, of which the varzea is the theatre. To witness, close at hand, the operation of many of the processes of which these sciences treat, and which have given form and character to the surface of our planet, I know of no region equal to the Amazonas. Between the water and the land, the river and the varzea, there is a constant conflict. Islands are formed and destroyed, or floated bodily down stream, by the continual process of destruction at one end, and of formation at the other; lakes, furos and paraná-merins are being formed, to be again filled up; tributaries extend themselves into the territory proper to the main river, or this throws out one of its lateral channels, to appropriate to itself a part of the valley of a tributary. The conflict, however, is unequal; the force of the river, irresistible as it is in its great floods, is spasmodic in its action, and can be met by a weaker, more constant one, such as is afforded in aid of the growth of the land, by the vegetative force. PROC. AMER. PHILOS. soc. XVIII. 103. w. PRINTED MARCH 11, 1879. [Jan. 17, Rank behind rank, the various aquatic and marsh plants advance into every shallow, building it up to the common level over which the floods pass, adding new sediment, instead of carrying away that already accumulated. In this way the land is slowly extending itself, confining the river more and more to its proper channel; but this process cannot materially alter the character of the valley, unless aided by some convulsion of nature. Much yet remains to be done on the Lower Amazonas, in filling in the details of this imperfect sketch, which will, I trust, be found to be accurate in the main, and which will serve to show how interesting the region is in itself, and in its relation to the rest of the Continent. Of the Upper Amazonas or Marañon region, enough is already known to show its surpassing interest and importance. Between the two, the middle or Solimões region, is an almost perfect blank, in which future explorers will meet with difficulties, even surpassing those presented by the other regions, but will, by well directed efforts, reap results commensurate with the hardihood of the undertaking. Stated Meeting, January 17, 1879. Present, 11 members. Vice-President, Mr. FRALEY, in the Chair. A letter of acknowledgment was received from the Natural History Society, Emden (100; List). Letters of envoy were received from the French Minister of Public Instruction; and the Meteorological Office, London, December, 1878. A letter of thanks for correspondence was received from the Rev. Stephen D. Peet. A letter respecting exchanges was received from Mr. G. W. Ranck, Curator of the Kentucky Historical Society. Donations for the Library were received from the Adelaide Observatory; M. P. Volpicelli at Rome; the Geographical Society and Revue Politique at Paris; the Meteorological Office, and Register, and London Nature; the Boston Natural History Society; American Journal of Arts and Sciences; Library Journal in New York; the Franklin Institute, College of Pharmacy, Journal of the Medical Sciences, and Medical News in Philadelphia; the American Journal of Mathematics at Baltimore; Mr. S. H. Scudder; the Botanical Gazette; Mr. G. W. Ranck; and the Ministerio de Fomento in Mexico. The American Journal of Mathematics of Baltimore was ordered to be placed on the list of correspondents to receive the Proceedings. The death of the Rev. E. R. Beadle, D.D., LL.D., in Philadelphia, January 6, 1879, aged 66, was announced by the Secretary; and, on motion, Dr. Robt. E. Rogers, was appointed to read an obituary notice of the deceased. The death of Mr. Morton McMichael, in Philadelphia, January 6, 1879, aged 71, was announced by Mr. Price; and on motion Mr. Fraley was appointed to read an obituary notice of the deceased. A letter from Mr. P. W. Sheafer, dated Pottsville, Pa., January 6, 1879, reported the result of tests of the visibility of stars in daylight from various depths of the 1600 feet shaft of the Philadelphia and Reading Railroad Company, near that borough: POTTSVILLE, Pa., January 6, 1878. DEAR SIR-The question of seeing stars from deep wells, &c., being unsettled, I requested Mr. Edward Herbert, an intelligent boss miner, now in charge of the deep shaft of the Philadelphia and Reading Coal and Iron Company, near this borough, to test the question so far as he could find the opportunity to do so in his frequent ascents and descents of the Pottsville shaft, especially, which is some 1600 feet deep. He reports as follows: "ST. CLAIR, December 20, 1878. "Myself and one of the workmen have tried this afternoon at several distances in east shaft, if we could see any stars, but failed to see any. The sky was very clear and atmosphere favorable; the shaft is a down cast, and was entirely free from smoke or steam. I fear we will not be able to solve your problem in the affirmative." In reply to a further inquiry, as to the depth from which observations were made, he replies as follows: "ST. CLAIR, January 4, 1879. "We have tested it at different depths, from 100 feet down to 700 and 800 feet, when the sky has been clear, but have so far failed to see any stars. [Jan. 17, After we got down 600 feet the atmosphere is not quite so clear as it is nearer to the surface." If your society can suggest further tests I will be glad to make them. I am very respectfully your obedient servant, TO THE AMERICAN PHILOSOPHICAL SOCIETY, P. W. SHEAFER. Mr. B. Britton exhibited a small and useful specimen-rock crusher for laboratory use, with mortar and pestle, and described its value in the saving of time and labor. Mr. Lesley exhibited a proof sheet of Mr. J. F. Carll's colored map of the preglacial water basins of North-western Pennsylvania, prepared for the illustration of his forthcoming third Report of Progress in the Survey of the Oil Regions. Mr. Marks exhibited and explained a new link-work, which he had invented for the use of his students in describing arcs of epicycloid curves, and which can be made. practically useful for plotting the outlines of the teeth of wheels. He also exhibited specimens of other Peaucellier cell forms. On motion, Mr. Lesley was elected Librarian for the ensuing year. The Standing Committees for 1879 were then appointed, as follows: Finance. Mr. Frederick Fraley, Mr. E. K. Price, Mr. Benjamin V. Marsh. Publication. Dr. John L. LeConte, Dr. Daniel M. Brinton, Dr. McQuillen, Prof. E. Thompson, Dr. C. M. Cresson. 1879.] Hall. Gen. Hector Tyndale, Mr. J. Sergeant Price. Library. Mr. E. K. Price, Dr. G. H. Horn, Prof. Houston. Pending nominations Nos. 871, 872, 873 were read, and Nos. 871 and 873 balloted for. No. 872 was postponed on account of the absence of its nominators. The reading of the list of members was postponed. On a scrutiny of the ballot boxes by the presiding officer, the following were declared duly elected members of the Society: Charles B. Dudley, Ph. D., Altoona, Pa. Philip H. Law, of Philadelphia. And the meeting was adjourned. Stated Meeting, February 7, 1879. Present, 19 members. Vice-President, Mr. FRALEY, in the Chair. Letters accepting membership were received from Dr. Charles Benjamin Dudley, dated Altoona, January 20, 1879; and from Mr. Philip Howard Law, dated Philadelphia, January 20, 1879. Letters of envoy were received from the Batavian Society of Sciences, Batavia, dated December 15, 1874, August 20, |