284 



NATURE 



[December 29, 1910 



of energy available for and adaptable to manufacturing 

 purposes. Among these water-power stands pre-eminent, 

 especially since the introduction of electricity, which has 

 provided an easy and convenient means for the trans- 

 mission of its energy. Then, in regard to flood preven- 

 tion, domestic water supply, irrigation, and land reclama- 

 tion there are obvious grounds for regarding the study of 

 periodic flow in rivers and streams as a consideration of 

 the highest importance. The damage arising from floods 

 in the United States exceeds a hundred million dollars 

 annually, and more than 70 million acres of the richest 

 land are rendered practically worthless by reason of pre- 

 vailing conditions of overflow and swamp. Amelioration 

 of these natural defects can only be brought about by the 

 collection of trustworthy data and a careful and thorough 

 study of all the circumstances attending the phenomena in 

 question. 



Records of stream flow necessarily call for frequent and 

 prolonged observation. They must embrace all stages and 

 cover, if possible, the absolute maximum and the absolute 

 minimum of discharge. This involves, in most cases, a 

 period of at least five or ten years, and in some instances 

 twenty years or more. It is regrettable that the com- 

 pilers of these volumes have had to avow that a number 

 of their records are of insufficient duration, owing to 

 unforeseen reduction in grants and the consequent 

 abandonment of certain gauging stations. The national 

 exchequer is surely not so impoverished as to be under 

 the necessity of exercising retrenchment in regard to so 

 important a branch of the public service. 



Three methods of stream-flow measurement have been 

 adopted by the Hj'drographical Department, according to 

 the local physical conditions, the degree of accuracy 

 desired, the funds available, and the length of time devoted 

 to observation. 



The first, most theoretical, and least used method is 

 that of measuring the slope and cross-section of a stream, 

 and then using the Kutter expansion of Chezy's formula. 

 Owing to the difficulty of obtaining accurate data, and 

 more particularly to the uncertainty attaching to the 

 coefficients in the formula, results obtained by this method 

 can only be regarded as approximately correct. 



The second method is that of measuring the discharges 

 over dams and weirs. Here the problem is complicated 

 by variations in profile and crest, by leakages through 

 the dams, backwater at high stages, log and ice obstruc- 

 tions, and local diversions of water for power purposes. 

 On this account comparatively few stations are main- 

 tained at weirs and dams. 



The system chiefly employed is that of measuring the 

 velocity of the current, principally by the Price current 

 meter, rarely by means of free floats, and, at the same 

 time, determining by a series of ordinates from a datum 

 line the cross-sectional area of the stream. 



The following comments on the relative merits of the 

 systems are interesting. 



" Practically all discharge measurements made under 

 fair conditions are well within 5 per cent, of the true 

 discharge at the time of observation. Inasmuch as the 

 errors of meter measurements are largely compensating, 

 the mean rating curve, when well defined, is much more 

 accurate than the individual measurements. Numerous 

 tests and experiments have been made to test the accuracy 

 of current-meter work. These show that it compares very 

 favourably with the results from standard weirs, and, 

 owing to simplicity of methods, usually gives results that 

 are much more reliable than those from stations at dams, 

 where uncertainty regarding the coefficient and compli- 

 cated conditions of flow prevail." 



Then there is, of course, the human element and the 

 personal factor which enters into all experimental work. 

 \t is interesting to know that, " with relatively few excep- 

 tions, the observers perform their work honestly." Yet 

 even honesty of purpose cannot eliminate every element 

 of error, though the effect of numerous readings is 

 obviously to minimise any inadvertent inexactitudes. 

 Individualism counts for something, too, but, on the 

 whole, errors arising from these and other causes become 

 self-compensating and virtually negligible. 



Merely to enumerate all the river basins comprised 

 within the purview of the Hydrographical Survey would 

 involve more space than can be spared for the purpose. 

 NO. 2148, VOL. 85] 



From the noble Mississippi, with its drainage area of 

 1,240,000 square miles, including wholly, or in part, thirty 

 States, besides a small portion of the Dominion of Canada, 

 down to the modest Siletz, with its length of 50 miles 

 and its basin of 320 square miles, there are measured 

 and described all sorts and conditions of streams with 

 names as musical as Menonimee and Wapsipinicon, as 

 dissonant as Umpqua and Puyallup, prosaic as Muddy and 

 fantastic as Devil's. The whole area of the country is 

 to be covered by a dozen bulletins, of which the present 

 seven form part, B. C. 



PALAEONTOLOGICAL PAPERS. 

 I^HE troublesome question of fucoids has exercised Mr. 

 Otto M. Reis (" Zur Fucoidenfrage," Jahrb. k.k. 

 geol. Reichsanstalt, Bd. lix., published 1910, p. 615), an 

 author well known for his researches on ruin-marble and 

 cone-in-cone. He accepts an organic origin for the fucoids 

 collected by him in the northern Apennines and the Alps, 

 and points out that the clay, which might be regarded 

 as a mere infilling of a worm-tube, is in some cases so 

 arranged as to form a true wall to the tube. The 

 granulations on the surface of many fucoids may be re- 

 garded as due to clay-lumps used in the construction of 

 the worm-tube. Terehella figulus is cited (p. 628) as an 

 example of a worm that kneads up fine clay into bricks, 

 as it were, which it places from its mouth on to the grow- 

 ing margin of its tube. The author expects criticism, 

 since he sets aside the algal theory of the origin of fucoids 

 in the Flysch, and ascribes the structures to boring and 

 tubicolous worms. 



Mr. E. W. Vredenburg (Records, Geol. Survey of India, 

 vol. xxxvi., 1908, p. 241) has described certain " pseudo- 

 fucolds " of eastern Baluchistan as casts of worm-burrows 

 and tracks of marine organisms, here following the work 

 of Nathorst. 



Mr. M. D. Zalessky records iBiill. Acad. imp. Sci. St. 

 Petersbourg, No. 6, 19 10) in a brief English paper the 

 discovery of coal-balls in the Carboniferous of the Donetz 

 basin, containing well-preserved plants, from the study of 

 which much may be expected. Their mode of occurrence 

 precisely resembles that of the English examples studied 

 by Williamson. 



Mr. Vredenburg (Rec. Geol. Surv. India, vol. xxxvi. . 

 p. 171) describes species of Orbitoides from the upper part 

 of the Upper Cretaceous of India, including megaspheric 

 and microspheric forms. As usual, this author interest- 

 ingly connects his palaeontological work with zonal con- 

 siderations and with questions of Indian stratigraphy, 

 which here occupy twenty-five pages of the paper. 



The important manuscript work on dendroid graptolites, 

 left bv Dr. R. Gurlev, has been revised and issued bv 

 Mr. R. S. Bassler (Bull. 65, U.S. National Museum'. 

 1909). The forms described, including many species of 

 Dictyonema, are from the Niagaran (Middle Gotlandian) 

 Dolomites of Hamilton, Ontario. With one or two excep- 

 tions, like the Inocaulis on p. 48, the figures of these 

 difficult fossils are limited to the forms of the rhabdo- 

 somes. 



Proceeding to molluscs, Dr. A. Schmidt has examined 

 the Anthracosiidae of the Upper Carboniferous beds of 

 Mahrisch-Ostrau (Jahrb. k.k. geol. Reichsanstalt, Bd. 

 lix., published in 1910, p. 733). The forms illustrated have 

 naturally an interest for English geologists, and the paper 

 both supports and supplements the work of Dr. Wheelton 

 Hind. Dr. Schmidt points out the general tendency 

 towards a uniform type of shell among the later members 

 of this fresh-water group, while the animals very prob- 

 ably remained quite distinct. The reduction of hinge- 

 teeth seems related to prolonged fresh-water conditions. 

 The author doubts if the fresh-water shells of the Mesozoic 

 era had fresh-water Paleeozoic ancestors, since the Permian 

 forms had already proceeded far towards uniformity of 

 type, and probably altogether passed away. However, a 

 mollusc described by Mr. L. J. Wills in a paper on the 

 Keuper of Worcestershire, to be quoted later, seems 

 possibly a survival of Naiadites. In the same volume of 

 this Jahrbuch (p. 407, published in 1909) Dr. A. Till con- 

 tinues his work on the jaws of fossil cephalopods. In the 

 absence of any guide to their correlation, these objects are 



