January 28, 1898.] 



SCIENCE. 



143: 



employed in setting them up. He then demon- 

 strated how easily, comparatively speaking, 

 the Pyramids could have been constructed by 

 these simple methods, and when completed the 

 earth around them which had been used for the 

 inclined planes filled into the pits from which 

 it was taken, leaving the ground as level as be- 

 fore. 



As an illustration the Pyramid of Gizeh was 

 cited, some of the stones of which were trans- 

 ported a distance of five hundred miles. In 

 this case the highest embankment necessary 

 when the workmen reached the top course, as- 

 suming that a 20 fo grade was adopted, would 

 have been 750 yards long, containing, as it did, 

 some seven and a half million cubic yards, pro- 

 vided the sides of the embankment would stand 

 at an angle of 30°, which is not at all improb- 

 able. A force of ten thousand men could have 

 built such an embankment in a single twelve- 

 month, a very small part of the total labor 

 which it is stated called for the services of one 

 hundred thousand men for twenty years. 



In the solution of the problem of putting in 

 place huge monoliths it was suggested that the 

 modern engineer could well consider the utiliza- 

 tion of inclined planes before adopting a more 

 complex method. 



The second paper was by Dr. T. J. J. See, of 

 the Lowell Observatory, on ' Recent Discoveries 

 of Double Stars in the Southern Hemisphere.' 

 He recalled the climatic studies which led Mr. 

 Lowell to locate the Observatory at Flagstafl", 

 Arizona, and stated that what is needed now is 

 not better telescopes, but better atmosphere. 

 Since August, 1, 1896, he has been engaged on 

 an extensive campaign for the discovery and 

 measurement of double stars. Some 100,000 

 stars between — 15° and — 45° of declination had 

 been examined and about 1,000 systems meas- 

 ured. He announced that he had forwarded to 

 the Astronomical Journal a catalogue of 500 

 new double stars, many of which are of the 

 highest interest. 



The third paper was by Mr. C. D. Walcott, 

 on the United States Forestry Reserve, which 

 will be published in full in the Popular Science 

 Monthly. 



E. D. Preston, 



Secretary. 



GEOLOGICAL SOCIETY OF WASHINGTON. 



At the meeting of the Geological Society, of 

 Washington, held on January 12, 1898, Mr. C. 

 Whitman Cross, of the United States Geolog- 

 ical Survey, read a paper on ' The Geological 

 vs. the Petrographical Classification of Rocks.' 

 This paper was an argument in favor of dis- 

 tinguishing between the systematic classification 

 of rocks as concrete objects, in accordance with 

 which they are described and named, i. e., the 

 petrographical classification, and the geological 

 classifications necessary from several points of 

 view. Many of the latter arrangements, such 

 as that expressing genetic relationships of 

 igneous rocks, are based on theory or hypothe- 

 sis and produce instability if introduced into 

 the systematic classification. It was urged that 

 neither geological occurrence nor genetic rela- 

 tions should be used in sub-classification of 

 igneous rocks. This paper will soon be pub- 

 lished in full in the Journal of Geology, Chicago. 



Arthur C. Spencer read a paper on ' The 

 Upper Cretaceous Section in Southwestern 

 Colorado. ' For the purposes of geological map- 

 ping in southern Colorado it has been found 

 necessary to subdivide the Upper Cretaceous 

 section in a manner differing from that of com- 

 mon usage in the Rocky Mountain area. The 

 Dakota occurs with its usual characters. Above 

 it comes a series of shales, known to embrace 

 the Benton, Niobrara and a part of the Pierre, 

 which cannot be divided on lithologic grounds. 

 The fossil-bearing layers are not persistent or 

 numerous enough to serve as guides in areal 

 mapping. 



The upper part of the section has not re- 

 ceived detailed examination. It consists of 

 massive sandstones in which both the Fox 

 Hills equivalent and that of the Laramie may 

 prove to be present. This sandstone is over- 

 lain by the Animas beds, which are probably 

 equivalent to the Denver beds of the Denver 

 Basin. W. F. Moesell. 



TJ. S. Geological Survey. 



THE academy op SCIENCE OF ST. LOUIS. 



At the meeting of the Academy of Science of 

 St. Louis on the evening of January 8, 1898, 

 nineteen persons present, the following officers 

 for 1898 were installed: President, Edmund 



