I50 



NATURE 



\_Dec. 25, 1873 



This basin consists of the two haunch bones which meet 

 together in front, but behind are separated by tlie lower 

 part of the backbone (called the sacrum), to which the 

 haunch bones are attached, and which forms the hinder 

 portion of the pelvis. The pelvis has a depression, or 

 " socket," on each side, into which fits the head of one of 

 the thigh bones. Each " haunch bone " consists of three 

 parts, which are, in man, primitively distinct, but after- 

 wards anchylose together, and all three elements (in each 

 haunch bone) take a share in the formation of the bony 

 thigh-socket, or acetabulum. These three elements are 

 named — i, ilium ; 2, ischiain : and 3, pubis. It is the 

 ilium which is adjoined to the sacrum. The pubis, in 

 man, meets its fellow of the opposite side in the middle 

 line in the front of the body. The two ischia (one to each 

 haunch bone) support man's body when in a sitting pos- 

 ture. 



The pelvis of man is often quoted as one of the most 

 peculiar and characteristic parts of his skeleton, and its 

 shape in him is very peculiar. Nevertheless the pelvis as 

 it exists in frogs and toads is a far more exceptional 

 structure. It is so in the extraordinary elongation, yet 

 small vertebral attachment, of the haunch bones ilia, as 

 also in the fact that these bones as well as the other pelvic 

 elements {ischia ^nApiibcs) are all closely applied to each 

 other in the middle line of the body. Thus these ele- 

 ments form a bony disc, and the two sockets {acctabula) 

 destined, respectively, for the heads of the two thigh 

 bones, come to be closely approximated one against the 

 other. The great elongation and small attachments of 

 the iha allow the pelvis as a whole to be bent upon the 

 backbone. Thus the hinder part of the body is moveable 

 and forms as it ^vere an additional common root segment 

 for the two limbs. 



St. George Wivart 

 ( To be continued^ 



SOUNDINGS IN THE NORTH PACIFIC 

 /~\VER a year ago the United States Congress autho- 

 ^-^ rised preliminary measures for laying a submarine 

 cable from the west coast of America to Japan. The 

 United States steamer Tuscarora, then on duty off the 

 Isthmus of Darien, was despatched on this business, and 

 started September 22, I S73, from San Francisco for the 

 Straits of Juan de Fuca. Reconnaissances off Victoria, 

 Vancouver's Island, discovered a gradually shelving 

 bottom in all respects suitable for a cable landing. The 

 steamer coaled at Nanaimo. Coal is also found at New- 

 castle Island, which is not far distant. It may be men- 

 tioned that the coal of this region is semi-bituminous, 

 and that recent discoveries have largely increased its 

 product. 



The line of soundings extended along a great circle 

 drawn from Cape Flattery to Oonalaska Island. At lat. 

 53° 58' N., long. 153° W., within about 400 miles of 

 Oonalaska, the coal was exhausted, and the vessel re- 

 turned to Victoria. The ocean bed sank rapidly from 

 Cape Flattery to lat. 48° 54' N., long. 126° 21' W., then 

 rapidly and steadily to lat. 49° 26' N., long. 128" 37' W., 

 then more rapidly to lat. 49^ 46' N., long. 129" 27' W., at 

 which point the depression was 1,452 fathoms. Thence 

 a peak rose in the sea bottom, with a summit at 1,007 

 fathoms depth, in lat 5 1" 40' N. long, 137" 32' W. Its rise 

 was fully as rapid as the depression preceding it, and the | 

 depression beyond it, the side being equally steep, was 

 somewhat greater. The slope after the western bottom 

 of this submarine mountain was reached was exceedingly 

 gradual, and somewhat undulating. Perhaps the fol- 

 lowing estimates, rouglily made from a sketch, will give a 

 clearer notion of the ground surveyed. At about too 

 miles from Cape Flattery, depth about 400 fathoms ; at 

 150 miles, 1,000 fathoms ; 170 miles, 1,400 fathoms ; 200 

 miles, ijOco fathoms ; 300 miles, 1,600 fathoms ; 400, 



1,900 fathoms ; 500, 2,000 fathoms ; 600, 2,000 fathoms ; 

 700, 2,100 fathoms; 800, 2,200 fathoms; 900, 2,300 

 fathoms ; 1,000, 2,300 fathoms ; 1,100, 2,50c fathoms. 



During soundings on the return voyage to San Fran- 

 cisco, another submarine mountain was discovered in 

 lat. 41° 30' N., long. 127° 11' W., the depth at its summit, 

 which the sounding instruments showed to be of a rocky 

 character, being only 996 fathoms. Around it, at dis- 

 tances of 20 miles, the depth was between 1,600 and 

 1,700 fathoms. 



The water temperatures along the line of soundings for 

 the cable, at depths of over 1,000 fathoms, varied from 

 0° 45' C. to 2° 43' C. ; surface, 10° 35' C. to 14' 15' C. In 

 lat. 53° 58' N., long. 153° 00' W., the increase from 50 

 fathoms to surface, was gradual ; but at 50, 100 and 200 

 fathoms the same temperature was found as at 2,500 

 fathoms. 



The conclusion has been reached in the course of a 

 series of observations made during the return voyage, and 

 subsequently, that what is known as the " California 

 coast current," is really a warm, and not as hitherto 

 supposed, a cold stream. The observations determined 

 the existence of a warm current, presumably a continuation 

 of the " Great Japanese Circle Current," setting toward 

 the south and east, of a surface temperature averaging 

 15° C, between the positions lat. 48° 36' N., long. 126° 

 36' W., and lat. 50" 34' N., long. 131° 38' W. Outside of 

 this current the temperature was but 10° C. Its width, 

 between what is known as " Fleurier's Whirlpool " and 

 the coast of California, is about 700 miles ; its depth in 

 lat. 44° 54' N.,long. 125" 13' W. is about 200ft. ; its speed, 

 one to two knots per hour. Under-currents below this 

 stream have been determined, setting to the north and 

 west. The counter-current does not appear to extend 

 more than 30 to 35 miles from shore, moving at a half to 

 one knot per hour, with a depth of 200 to 300 fathoms. 



The expedition was equipped with a great variety of 

 sounding apparatus, of which only a few instruments gave 

 perfect satisfaction, and several proved quite useless. 

 The vessel carried 32,000 fathoms line, of which 21,000 

 v.-ere ij in., carbonised. Among the satisfactory instru- 

 ments. Prof. Thomson's is mentioned. This is worked 

 by hand, winding No. 22 piano wire, capable of resisting 

 a strain of 200 pounds. It has a registering indicator 

 and a dynamometer attached. For bringing up material 

 from the bottom, Belknap's cylinder, No. 2, gave the best 

 results, the lower half of the c\linder being usually filled 

 with about three ounces of sea-bottom material, and the 

 upper half with water that had rested on the sea-bottom. 

 The material is brought up secured in the case of a 

 '■ Sand's cup " by a cylindrical sleeve. The latter is held 

 by a spiral spring, in a position just covering a small 

 orifice in the hollow cyhndrical case. On striking 

 bottom, the sleeve is forced up, permitting the material of 

 the ocean bottom to enter the orifice. The instrument is 

 driven into the bottom material by a weight which carries 

 it down with great velocity. This weight, consisting of 

 two hemispheres of iron attached just above the spring, 

 is automatically detached when bottom is struck, by the 

 slackening of the line. Upon drawing up the line, the 

 spiral spring again forces the sleeve down, covering the 

 orifice. The material drawn from the greatest depths 

 was the usual challvy, pasty mud, smooth and homo- 

 geneous, rarely containing sand, chiefly composed of 

 casings of diatoms and foraminifers, with here and there 

 the spicula; and siliceous skeletons of the smaller sponges 

 and polycysiiua. 



Although the expedition met for the most part witli un- 

 settled and unfavourable weather which interfered with its 

 work, that which it has accomplished is regarded as emi- 

 nently satisfactory. There is little doubt but that the route 

 upon which the soundings have been made, will be the one 

 selected for the cable ; and next spring the work will be 

 extended from the point at which it was discontinued. 



