76 SEA AND LAND 



inspired, it would seem, b\- tiic pleasure of dangerous cruis- 

 ing. It is principally among the people who share this 

 Scandina\ian blood that we hnd that vivid interest in all that 

 pertains to the ocean which has led to some of the most 

 fruitful and interesting incjuiries of modern science ; researches 

 w^hich have created the brancli of learning which is termed 

 thalasograph.y, or the description of the ocean. 



The study of the ocean depths is an extremely difficult 

 incpiiry : we know far more concerning the form of the 

 moon's surface, though that sphere is a quarter of a million 

 miles away, than we can ever hope to learn of the shape of 

 the ocean-floors. There are few instruments as yet devised 

 which can give us any considerable information as to the 

 conditions at any great depth below the surface. A century 

 ago the only apparatus of submarine research was the 

 plummet, by which the navigator, to learn the position of 

 shallows, sounded for the depth of at most a few hundred 

 feet. A little tallow on the bottom of the lead brought up 

 some fragments of the sea-iloor, and showed whether it was 

 sandy, muddy, or covered with fragments of shells. A 

 hundred years ago nothing was known as to the greater 

 depths of the ocean. The lines to which the sounding leads 

 were attached were limited in length to about six hundred 

 feet ; when the bottom was not found with them, the vessel 

 was said to be "off soundings." The depth beneath her keel 

 was then left to conjecture. With the modern increase in 

 curiosity concerning the ocean, the lines were lengthened and 

 the weights increased, so that some information began to be 

 obtained as to the deeper parts of the sea. But there were 

 many and serious difficulties encountered in these explora- 

 tions. The ropes had to be of considerable size to sustain 



