April 19, 1900] 



NA rURE 



601 



We have received also Parts i., iv. and vi. of the "Nine- 

 teenth Annual Report for 1897-8," and portions of Part ii. 

 Part i. comprises the report of the director, Mr. Charles D. 

 Walcott, and it includes observations on triangulation and 

 spirit-levelling. 



Part ii. , which includes papers chiefly of a theoretical nature, 

 contains an elaborate report on the principles and conditions of 

 the movements of ground-water, by Mr. F. H. King. The 

 author deals with the water-holding capacity of natural soils, 

 the depth to which ground-water penetrates, and its general 

 movements. Movements are due to barometric pressure and to 

 thermal agencies, to crust deformation and to rock consolida- 

 tion. The original water laid down with sediments is con- 

 sidered as well as the subsequent capillary movements of ground- 

 water. Interesting results are given of experimental investi- 

 gations regarding the flow of water and kerosene through sand, 

 sandstone, wire-gauze, &c. ; and of the influence of the form, 

 diameter and arrangement of soil and sand-grains on the 

 amount of flow. An important record is given of the effect of 

 the pumping of one well on another 1 133 feet distant. Both wells 

 were sunk in sandstone to a depth of about seventy feet. When 

 pumping at the rate of about seventy-five gallons per minute 

 from one well, a fall of water was detected in the other after 

 the lapse of one minute and forty-five seconds. The pump 

 was worked for ten minutes, and the fall of water in the second 

 well continued for nearly fifteen minutes. 



The article by Mr. King is followed by one on the theoretical 

 investigation of the motion of ground- waters, by Mr. Charles S. 

 Slichter. 



An elaborate memoir on the Cretaceous formation of the 

 Black Hills (Rocky Mountains), as indicated by the fossil 

 plants, is communicated by Mr. Lester F. Ward, who has had 

 the assistance of Messrs. W. P. Jenney, W. M. Fontaine and 

 F. H. Knowlton. The forms described include a number of 

 silicified Cycadean trunks, Conifers, Ferns and Equisetaceae, 

 also Dicotyledons belonging to the beech, oak, elm, mulberry 

 and soapberry families. The work is illustrated by over a 

 hundred plates, including one of Cycadean trunks from the 

 Purbeck beds of the Isle of Portland, England, belonging to 

 the U.S. National Museum. 



Part iv., a volume of 814 pages, deals with hydrography : it 

 contains a report, by Mr. F. H. Newell, on stream measure- 

 ments ; and an account, by Mr. Edward Orton, of the Rock 

 waters of Ohio. The knowledge of the Ohio waters is mainly 

 due to the boring operations in search of oil and gas. Mr. 

 N. H. Darton furnished a preliminary report on the geology 

 and water resources of part of Nebraska. Several illustrations 

 are given of tors or outstanding masses of sandstone which, from 

 being locally hardened, have withstood the effects of denuda- 

 tion. Other instances of fantastic weathering, seen in the 

 "Chimney Rock" and "Toadstool Park," are effectively 

 shown in plates. 



Part vi. (in two volumes) contains an account of the mineral 

 resources of the United States. In the first volume, the metallic 

 products, coal and coke are dealt with ; in the second volume, 

 petroleum, natural gas, stone, clays, cement, precious stones, 

 phosphates, mineral paints, &c. There are also notes on the 

 mineral resources of Hawaii, and of the Philippine Islands. 



Monographs of United States Geological Survey. 

 The twenty-ninth volume of the Monographs of the United 

 States Geological Survey is a large work of 790 pages, on the 

 geology of Old Hampshire county, Massachusetts, by Professor 

 Benjamin K. Emerson. It is an elaborate memoir embodying 

 personal observations which have extended over more than a 

 quarter of a century ; and it deals with a great variety of forma- 

 tions — Algonkian, Cambrian, Silurian, Devonian, Triassic and 

 Pleistocene— also with various eruptive rocks, and their many 

 economic products. In the Algonkian series there are gneisses 

 often granitoid, and others yielding much graphite, likewise 

 magnesian limestone. Of Cambrian age are various gneisses 

 and associated schists and quartzite. A detailed description is 

 given of the granitoid gneiss of Monson, which is e.\tensively 

 quarried, the yearly output being from twenty to thirty thousand 

 tons. The author draws attention to a remarkable tendency to 

 expansion which has been stored up in the gneiss, causing 

 blocks to elongate when they are quarried. In the same way 

 the expansion causes the horizontal sheets of the rock to rise, 

 often quite suddenly, in considerable anticlines, with the arch 

 as much as fifty feet long and the rise three or four inches. These 



NO. 1590, VOL. 6(] 



anticlines form sometimes with explosive violence, throwing 

 large fragments of the rock more than two feet from their 

 original position. Evidently the rock has an elastic stress 

 which expresses itself in expansion when the surrounding masses 

 are removed.^ 



Among the rocks classed as Lower and Upper Silurian are 

 sericite-schists, amphibolites and .serpentines, of which petro- 

 graphical descriptions are given. Not the least interesting 

 feature in the geology is the great magnetite-emery bed which 

 lies along the junction of hornblende-schist and sericite-schist, 

 and was discovered in 1864. The emery is distinguished from 

 corundum (pure anhydrous alumina) which also occurs, and is 

 regarded as an aluminate of iron. A full account of this mineral 

 vein is given. 



When we come to the Devonian rocks we still find a series 

 highly altered, comprising in the main quartzite, and various 

 schists, together with limestones. The rocks appear to rest 

 conformably on, and, indeed, to pass into what are called Upper 

 Silurian argillites ; nevertheless, the fossils, or rather impres- 

 sions of them, which were obtained in the rocks, seem to be of 

 upper Devonian type. Prof. J. M. Clarke remarks that they 

 "are so distorted, obscure, and closely packed together, that a 

 little imagination can construe them into species of all sorts of 

 ages " ; but he feels " reasonably secure " about a few, among 

 which is a large spirifer, like Spirifera disjuncta. Workers 

 among the Devonian rocks in parts of Devon and Cornwall 

 would feel sympathy with the difficulties of accurate identification, 

 and suspend judgment about the local relations of Devonian and 

 Silurian. In a general chapter on amphibolites the author 

 states that he has assigned most of them with more or less con- 

 fidence to the list of altered sedimentary rocks. Passing on to 

 the eruptive rocks, he describes various granites, aplite, quartz- 

 gabbro, tonalite or quartz-diorite, diorite, diabase, and cortlan- 

 dite (hornblende-pyroxene-biotite-peridotite). 



The Triassic rocks comprise a series of sandstones, conglo- 

 merates and red shales, together with diabases. The shales 

 contain impressions of salt-crystals, and among the conglomerates 

 the author finds evidence which suggests the former presence of 

 shore-ice. Most interesting are the observations on the preser- 

 vation of reptilian foot-prints and rain-drops which occur in 

 sandstones that rest on the broad sheets of trap. It is thought 

 that the iron set free from the decomposing lavas below per- 

 meated the sediments and favoured the preservation of the 

 tracks ; it is also suggested that the heat of these great trap- 

 sheets may have promoted rapid consolidation of the sand-layers 

 by which they were quickly covered. In a few notes on the 

 " Recent Progress in Ichnology," Mr. C. H. Hitchcock gives a 

 list of the Ichnozoa of the Trias, including one marsupial, and 

 many birds, dinosaurs, reptiles, batrachians, arthropods and 

 mollusca. 



In the account of Pleistocene phenomena we have references 

 to Pre Glacial drainage and erosion, descriptions of glacial lakes, 

 and minor grooves and notches, and particular accounts of the 

 till and various other drifts. The author remarks on the frag- 

 ments wornby the agency of land-ice "into the peculiar shapes so 

 characteristic of glacial accumulations, three- or four-sided forms, 

 with irregular ends more or less elongate as the rock was more 

 or less schistose, the sides fiat or broadly convex, joined by 

 rounded edges and scratched in various directions " ; and he 

 adds that " These peculiar forms, called by the Germans dreik- 

 antner, are as characteristic of the till as graptolites of the Silu- 

 rian." Numerous sections are given of glacial deposits, many 

 of which remind us of the drifts so well exposed on the coasts of 

 Norfolk and Suffolk, which exhibit similar structures and con- 

 tortions. The Pleistocene beetles are described by Mr. S. H. 

 Scudder. The volume, which is well illustrated, concludes with 

 a chronological list of publications on the district, the earliest of 

 which is a reference to an ancient catalogue (1734) of objects of 

 natural history formed in New England, by John Winthrop, 

 F.R.S. 



Monograph No. 31 contains an account of the geology of the 

 Aspen mining district, Colorado, by Mr. Josiah E. Spurr, and 

 it is accompanied by a large folio atlas of maps and sections. 



In an introduction, Mr. S. F. Emrnons points out that Aspen 

 is one of the most picturesquely situated mining towns of the 

 Rocky Mountain region ; and that its great mineral wealth lies 

 in a narrow belt of Palseozoic rocks, which are steeply upturned 

 against granite, and broken in the most complicated manner by 

 a network of faults. 



1 See also A. Strahan, on " Explosive Slickensides," Geol. Maj^. for 1887. 



