From Teneriffe to Sombrero. 59 



depth is greatly in excess of the scale of distance marked in 

 degrees of latitude and longitude. For example, in Plate 9, a 

 division of 100 fathoms is equal to two divisions, or two degrees 

 of the horizontal scale, representing 1 20 nautical miles, or about 

 1 20,000 fathoms, so that the proportion between the two scales 

 is as 1 to 1 200 — in other words, the depths in that diagram are 

 1 200 larger than the distances indicated by the horizontal scale. 

 The scale of depth, which stops at 1500 fathoms, represents 

 only about three-fourths, and often only one-half, of the total 

 depth of the oceanic basin ; and from the lowest isotherm ot 

 2 . 5 C, the temperature in most cases slowly decreases down to 

 the bottom, the depth and temperature of which at each station 

 are given in the table annexed to each diagram. 



The station numbers are the same as those on the labels 

 attached to the natural history specimens brought up by the 

 dredge, the trawl, or the to wing-net at each station. No doubt 

 these specimens, of which there are more than one hundred 

 thousand, embracing several hundreds of forms of animal life 

 never before beheld by the eye of man, and therefore highly 

 interesting not only to the student of zoology but to the public 

 in general, will be permanently exhibited in the shape of a 

 " Challenger Museum." Collected, as they have been, at a 

 great sacrifice of time, money, and, sad to say, of life, including 

 the ever-to-be-regretted death of Dr. Rudolf von Willemoes- 

 Suhm, the promising zoologist attached to the scientific staff of 

 H.M.S. ''Challenger," they will compose a lasting monument 

 of the generosity of the English nation, always ready to promote 

 the cause of knowledge, and prove of more enduring interest to 

 future generations than all the trophies of war bought at the price 

 of general ruin. 



Section from Teneriffe to Sombrero (Plate 6, Table I.). 

 — This section stretches across the Atlantic in a west-south- 

 westerly direction, and crosses the parallel of lat. 20 N. near 



