August 10, ISSn.] 



SCIENCE. 



153 



arouse, such a soc-icty might even secure a 

 small Ciiiul fur its maintenance. 



Last, and if siic-h a work be possible, best 

 of all. the association might, through a proper 

 committee, do much to promote science-teach- 

 ing in the schools of the cities where it each 

 year bides. Every meeting of the association 

 has among its attendants those who have the 

 much-needed skill in the matter of teaching 

 science. There is hardly a public school in 

 the land where there is not a crying need of 

 such help as could best be given at such 

 times. There should be a committee, or even 

 perhaps a section of the association, devoted 

 to the promotion of sound teaching in natural 

 science ; for the gravest danger before this 

 branch of learning is to be found in the radi- 

 cal imperfection of the methods of science- 

 teaching in use in our schools. These sugges- 

 tions may seem to lay heavj- burdens of 

 advice on the association, but none of them 

 seem beyond the promise of its strength. 



IIECEXT EXPl.OHAT/n.YS fy THE nR- 

 (ilUN OF THE OULF-SIHEAM uFF THE 

 EASTEliN COAST OF THE UNlTElJ 

 SIATEH BY IHE U. 6' FISH-COMMIS- 

 SlON.^ 



4. Nature and origin of the deposits. 



Along part of the (iulf-Stroam slope exam- 

 ined by us, tiie liottom. in ti.') to l.'iO fathoms, 

 80 to 110 miles from the shore, is composed 

 niainh' of very fine siliceous sand, mixed with 

 a little claj-, and containing alw.ays a consid- 

 erable percentage of the shells of Foraminifera 

 and other calcareous organisms, and frequentl)' 

 spherical, rod-like, and stellate sand-covered 

 rhizopoiis, sometimes in large quantities. 

 Among the Foraminifera, Globigerina is 

 abundant ; but many other forms occur, some 

 of them of large size and elegant in form. 

 Grains of green sand (glauconite) were fre- 

 quently met with, but were not abundant. 

 Large quantities of the tubes of annelids fre- 

 quently occur. .Some of these are made of 

 cemented mud, fine sand, or of gravel ; others, 

 of parchment-like secretions. On the inshore 

 plateau, and also in the deeper localities on the 

 slope, there is usually more or less genuine 

 mud or clay ; but this is generally mixed with 

 considerable fine sand, even in .300 to (100 

 fathoms. The sand, however, is otlen so line 



> C'ontiDucd from No. 10. 



as to resemble mud, and is frequently so re- 

 portc<l when the preliminary soundings are 

 made. In several localities the bottom was so 

 • hard,' in O.) to 125 fathoms, that the bulk of 

 the material brought up consisted of sponges, 

 worm-tubes, shells, etc., with some gravel, but 

 with neither mud nor fine sand. Such bottoms 

 were very rich in animal life. In man3' 

 instances, even in our deeper dredgings (about 

 700 fathoms) , and throughout the belt exam- 

 ined, we have taken numerous pebbles, and 

 small, rounded bowlders of all sizes, up to sev- 

 eral pounds in weight, consisting of granite, 

 sienite, mica schist, etc. Tlie.se arc abundant ia 

 some localities, and covered with Actiniae, 

 etc. Probably, while frozen into the shore-ice 

 in winter and spring, they have been recently 

 floated out from our shores and rivers, and 

 dropped in this region, where the ice melts 

 rapidly under the influence of the warmer Gulf- 

 fStream water. Probably much of the sand, 

 especially the coarser portions, may have been 

 tninsporled by the same agency. 



Another way, generally overlooked, in which 

 fine beach-sand can be carried long distances 

 out to sea, is in consequence of its floating on 

 the surface of the water after it has been ex- 

 posed to the air, and dried on the beaches. The 

 rising tide carries off a considerable amount 

 of dry sand, floating in this wa^". In our fine 

 towing-nets we often take more or less fine 

 siliceous sand which is evidentl}* flo.iting on the 

 surface, even at considerable distances from 

 the siiore. The vast sand-beaches, extending 

 from Long Island to Florida, aflbrd an inex- 

 haustible supply of this fine sand. 



The prevalence of fine sand along the Gulf- 

 Stream slope in this region, and the remarkable 

 scarcity of fine mud or clay deposits, indicate 

 that there is here, at the bottom, a current 

 usually sufficient to prevent, for the most part; 

 the deposition of fine argiMaceous sediments 

 over the upper portion of the slope, in (io to 

 l.jO fathoms. Such materials are jirobably 

 carried along, for the greater part, till they 

 eventually sink to greater depths, nearer the 

 liase of the slope, or l)eyond in the ocean-basin 

 itHielf, where the currents are less active. 

 Doubtless, there are also belts along wiiich the 

 northern current meets and opposes the Gulf 

 Stream, causing less motion, and fa\'tiring the 

 de|)osition of fine sediments. It is probable 

 that motion of the water along the upper part 

 of the sloiie may also lie caused by tidal cur- 

 rents, which would modify the north-eastern 

 flow of the (;ulf Stream, both in direction and 

 velocity. Currents prmluced b}- protractetl 

 storms might have the same effect. In depths 



