DEEP-SKA i:Xl'I.ni;ATI()N. IGT 



I'lal animal- \vri(« l.roiiulit up l»y llu- sounding-ciiji, l)ut tlic 

 expedition is nieniorahle as liavini; been the oceasion (tillic 

 lirst i)raelieal use of wire in sounding, for the important 

 improvements introduced hv the eommander into sounding 

 instruments and methods, and for tlie great depths obtained 

 in the norljjwestern j/art of the Paeilie. being 4,0")') fathoms, 

 the greatest depth ever measured by reliable means, and one 

 \\liieh is jirobably itttle, if at all, exeeedcd in any part of 

 tlu' oeean. This eruise terminated in August, 1X74. Since 

 then expeditions have multiplied, and to enumerate them 

 with the >\KUv at my eonniiand would be h.irdly more in- 

 teresting than the ineorporation of a statistical table into 

 this already, (in spite of its titli',) I fear, rather dry di.s- 

 conrsc. 1 cannot avoid, however, a reference to the hydro- 

 gra})hic work of the Baehe under Sigsbee and J5artlett, in 

 the GwU and ("aribl)ean sea, in i.S74-l879. Not only was 

 a greater area of deej) water more thoroughly worked out 

 l>y these otfici-is than has yet been equally explored in any 

 other ]»art of the globe, but the improvements in sounding 

 and <lredging apparatus made during the progress of the 

 work have almost revolutionized such investigations. These 

 have been in part alluded to already. During parts of 1877, 

 1878, and 187'.>, Professor Alex. Agassiz made one of the 

 j)arty, witli su})ervision over the dredging work. To him is 

 due, among many other details, the substitution of wire- 

 cable for hemi»-line in drc^'dging, which bore especially im- 

 })ortant fruit; and by him the most important scientific 

 results of these cruises were aiuiounced to naturalists. 



The historic i)art of this lecture nuist close with a mere 

 reference to the valuable work of the Norwegians, Sars, 

 Friele, Daniels.sen,etc., in the North Atlantic, on the steamer 

 X'iuingcn, (1870-8;) of Jeffreys, in II. M.S. \'alorous, (1875;) 

 Murray, in H. M. S. Knight Errant, (1880;) and the French 

 ex])edition of 1881, on the Travailleur. 



This model of the (hdf of Mexico, from the work of tlie 

 Coast-Survey hydrograi)liers, illustrates the topograpiiy of 

 that part of the sea bottom. You will observe the singular 

 plateau which extend- about the peninsula of Yucatan and 



