418 



SCIENCE. 



[Vol. IV., No. 91. 



22. Passed June 22, 1884; also plotted on the chart 

 as Nos. 17 and 18 in the positions in which it was 

 reported by two other vessels. 



23. Iron can-buoy, run into by a British bark June 

 17, 1884, about twelve miles from the Flemish Cap, 

 on the banks of Newfoundland. 



24. Large iron buoy, passed June 22, 1884, ' six- 

 teen miles south-west from Gay Head,' Martha's 

 Vineyard. 



25. Large iron conical-shaped buoy, passed June 

 24, 1884, forty miles west of Bishop, Scilly Isles, off 

 the west coast of England. 



26. Black barrel-buoy, passed June 29, 1884. 



27. Large red iron buoy, floating upright, passed 

 July 7, 1884, seven miles from Bishop Hock, Scilly 

 Isles. 



28. Very large red iron buoy, passed Aug. 4, 1884. 



29. Large conical-shaped iron buoy, passed Aug. 1, 

 1884. 



30. Large iron can-buoy, which from appearances 

 had been floating a very long time; passed Aug. 4, 

 1884. 



31. Second-class can-buoy, picked up on the banks 

 of Newfoundland, August, 1884. 



32. Second-class can-buoy, picked up about twenty- 

 five miles from Cape Elizabeth, Me., in August, 1884. 



voyage might add much to what we know of 

 the ocean-currents ; and if such objects were 

 set adrift simultaneously, from, say, Nan- 

 tucket, Penzance, Teneriffe, the Cape de Verde 

 and Turk's Island, or the Bermudas, we might 

 learn much more on this interesting subject. 



A. B. Johnson. 



DRUMLINS. 



The arched hills of glacial drift that have been 

 called drumlins by the Irish geologists are among the 

 most peculiar results of the action of land ice-sheets. 

 They are composed of closely-packed bowlder-clay, 

 or till, distinctly unstratified, and containing well- 

 scratched stones. They rest on a foundation of 

 glaciated rock, and rise in a smoothly rounded mass 

 from fifty to two or three hundred feet in height, reach- 

 ing from a quarter of a mile to two miles in length. 

 Their bases vary in form from a circle to a long, nar 



It would almost seem as if the buoys shown 

 on this chart had attempted a system of circle- 

 sailing, and as if several of them had nearly 

 gotten round to their moorings after having 

 circumnavigated the North-Atlantic Ocean. 

 How else shall we account for the position of 

 those picked up off the Canaries, those sighted 

 in the Sargasso Sea, those found off Turk's 

 Island and the Bermudas ? When some of 

 these data were presented to the Philosophical 

 society at Washington, and the matter was 

 discussed b}' naval, coast-surve} T , and light 

 house officers, the weight of the expressed 

 opinion seemed to be in favor of this theory. 



But the object of this paper is to call atten- 

 tion to the fact that the voyages of these buoys 

 show the trend of surface or submarine cur- 

 rents, of which we as yet know little, either as 

 to their direction, force, or times of flow. The 

 current indications on this chart show the ap- 

 proximate sum of our present knowledge on the 

 subject. It is evident that it would be greatly 

 to our advantage to know more. Science said 

 a short time ago that it was unfortunate that 

 the gas-buoy (No. 6) was picked up. Would 

 it not be in the interests of science, of com- 

 merce, and of navigation, if some such object 

 as that buoy, drawing as much water, floating 

 as lightly, showing as little surface to the 

 wind, and offering as little resistance to collid- 

 ing vessels, were allowed to float, and were 

 carefully watched until it should have gone 

 ashore ? And why could not some slow-sailing 

 vessel be detailed for such dutj T ? At any 

 rate, if such an object were set afloat and re- 

 ported by eveiy vessel which sighted it, its 



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m . i if./ w 



i-inJ 



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5miues. 



Fig. 1. 



row oval ; and, when elongated, their major axes are 

 closely parallel to the direction of former local glacial 

 motion. They are therefore easily distinguished in 

 form and structure from the rolling hills of terminal 

 moraines, and from the ridges and mounds of osar 

 and kames. Although they form pronounced fea- 

 tures in a landscape, their distribution is as yet 



