REPORT ON THE DEEP-SEA DEPOSITS. 
XV 
the deepest part of the ocean.^ Although the oceanic phenomena revealed at the surface 
of the sea were eagerly studied during, and immediately after, the time of the great 
discoveries to which we have just referred, the phenomena of the deep sea cannot be 
said to have engaged the attention of navigators and scientific men till after the lapse 
of several centuries. 
In the first half of the seventeenth century Kircher reviews the doctrines as to the 
depth of the sea accepted in his time. He says : — “ In the same manner as the 
highest mountains are grouped in the centre of the land, so also should the greatest 
depths be found in the middle of the largest oceans : near the coasts with but slight 
elevations the depth will gradually diminish towards the shore, I say coasts with but 
slight elevations, for if the shores are surrounded by high rocks, then greater depths are 
found. This is proved by experience on the shores of Norway, Iceland, and the Islands 
of Flanders.”^ 
The first attempt to represent the bottom of the sea by isobathic curves is to be 
found in a map by Philippe Buache in 1737. These curves are intended to show that 
certain elevations of the sea-bottom correspond with the orography of the neighbouring- 
land. In an essay on physical geography, published in 1752, he develops his ideas on 
this subject,^ 
Unsuccessful attempts were made by Captain Ellis in 1749, by Lord Mulgrave in 
1773, and by Scoresby in 1817, to sound the ocean. Sir John Ross was more fortunate 
in 1818. During his first Arctic expedition he brought up 6 lbs. of mud from 1050 
fathoms in Baffin’s Bay. Soundings were correctly obtained in 1000 fathoms in Posses- 
sion Bay, and worms and other animals were found in the mud procured. Sir James 
Clark Ross, during his Antarctic expedition,'^ after a number of unsuccessful attempts 
with the sounding lines in use, made a new line on board his ship, 3600 fathoms in 
length. With this a satisfactory sounding was obtained in 2425 fathoms in the South 
Atlantic, and another off the Cape of Good Hope in 2677 fathoms. On two occasions 
no bottom could be found with over 4000 fathoms of line. He also dredged successfully 
in depths of 400 fathoms. Some beautiful specimens of Corals, Corallines, Flmtra, and a 
few Crustaceous animals were obtained. 
A great impulse was given to deep-sea soundings when Lieut. Brooke, an officer in 
the United States Navy, invented his sounding machine in 1854, by which, applying 
Cusanus’ idea of a detaching weight to the sounding line, the sinker was detached 
when the weight struck the bottom. This instrument was modified and improved by 
Commander Dayman, who employed it while sounding across the Atlantic in the region 
through which the Atlantic cable would require to pass. The introduction of steel wire 
^ Pigaffetta, Premier voyage autour du Monde, p. 53, Paris, I’an ix. 
2 KircPer, Mnndus Subterraneus, p. 97. 
^ Buache, “Essai de geographie physique,” &c.. Hist, de I’Acad. des Sciences, 1752, p. 399. 
^ From 1839 to 1843, 
