Miscellaneous Intelligence. 225 



SCIENTIFIC INTELLIGENCE. 



00. Explorations of the Gulf Stream, by Lieut. J. E. Pills- 

 bury, U. S. N.— The Report for 1886 of the IT. S. Coast and 

 Geodetic Survey contains, in Appendix No. 11, a Report of new 

 Explorations of the Gulf Stream illustrated with maps, which 

 closes with the following conclusions (p. 289) : 



"I have to submit the following summary of my conclusions, 

 based upon the information obtained during the two seasons' 

 observations. The examination of the Gulf Stream currents hav- 

 ing been made in March, April, May, and June, the conclusions 

 may be incorrect for other seasons of the year, although there are 

 no good reasons for supposing that such is the case except, pos- 

 sibly, in the amount of the variations. 



(1) Between Fowey Rocks, Florida, and Gun Cay, Bahamas, 

 the current varies daily in velocity, at times as much as 2£ knots. 

 The greatest velocity is generally about nine hours before the 

 upper transit of the moon. The variations are most excessive on 

 the west side of the straits and least on the east side. 



(2) The average daily currents vary during the month, the 

 strongest set coming a day or two after the greatest declination 

 of the moon. 



(3) The axis of the Gulf Stream, or the position of the strong- 

 est surface flow in passing this point, is 11^ miles east of Fowey 

 Rocks Light-House. The strongest surface current found here 

 was 5^ knots per hour ; the least, If knots ; and the average, 3^- 

 knots. The average current at other places on either side of the 

 axis is as follows : 



Knots. 



Axis of the stream, 1 1\ miles from Fowey Rocks 3*6 



3£ miles west, or 8 miles from Fowey "Rocks 1 2 -6 



3-£ miles east, or 15 miles from Fowey Rocks 3*2 



10 miles east, or 22 miles from Fowey Rocks 2 - 8 



17 miles east, or 29 miles from Fowey Rocks _ 2 '4 



24 miles east or 36 miles from Fowey Rocks _■ 1*8 



(4) The wind probably retards or accelerates the velocity of 

 the current. A northeast gale in the Atlantic will probably 

 "breakup" the water of the stream, lowering its velocity ma- 

 terially, and afterwards the flow will, by the reaction, be greatly 

 increased over the normal speed. There is no evidence of any 

 change in position of the axis of the stream due to the wind. 



(5) Two days' observations off Jupiter Light, Florida, indicate 

 the same daily variation as was found off Fowey Rocks, and the 

 axis of the stream at this section is probably about 17 miles east 

 of the light." 



Appendix No. 12, in the same report, is a new and greatly 

 enlarged review of the "Secular variation of the magnetic declin- 

 ation in the United States and some foreign Stations, by Charles 

 A. Schott. It covers pages 291 to 407. 



