6r6 



SCIENTIFIC RECREATIONS. 



ever reached living, and from which we have no information? We can lay 

 our telegraph or telephone lines beneath the waves, and far from the restless 

 waves in those quiet depths where no billows can reach. What treasures 

 must lie hidden at the bottom of the sea ! The treasures, the gold and 

 silver, the merchandize, the wealth of centuries. The sailor lies sleeping 

 there 



" Serene and safe 



From tempest and from billow ; 



The storms that high above him chafe 



Ne'er rock his peaceful pillow " ! 



What can we hope to find at the bottom of the sea we cannot reach ? 

 Yes, but we can reach it. By sounding with Brooke's lead (a cannon ball, 

 as shown in the illustration), we can arrive at a certain knowledge of the 

 composition of the ocean bed. The right-hand figure of the two is the lead 



when being lowered, and while it is sink- 

 ing the cord remains tight. So soon as it 

 touches the bottom the weight of the 

 cannon ball divides the line, and the tube 

 is easily drawn up again. It has been 

 well greased, and so in the cavity of the 

 rod some shells and sand are found ad- 

 hering. These fragments tell us the com- 

 position of the bottom of the sea. 



Here we find tiny shells, just as we 

 find them in chalk, the same formation as 

 that which piled up the cliffs which have 

 risen from, or been discovered, by the sea. 

 By other ingenious contrivances water can 

 be fetched up from the bottom of the 

 Fig. 7 o 3 .-i3rooke-s Lead. ocean, and the temperature can be gauged 



all along the sounding line. The expedition of the Challenger brought many 

 interesting facts to light. Far down in these solitudes are marine animals, 

 Crustacea, star-fish, seaweeds, and shells, all of which are carried up by 

 the dredge worked by a steam engine; for the resistance is very great, and 

 the weight supported at the depth of two miles must be considerable, and is 

 equal to four atmospheres. A thermometer has come up crushed even in 

 its iron case, and so the creatures which inhabit and find means to live at 

 the bottom of the sea must be specially fitted by Nature for the locality. 



The configuration of the ocean bed has given rise to many different 

 opinions. It has been maintained that there arc mountains and valleys, 

 hills and dales underneath the water, all clothed with marine vegetation, 

 equal in height and depth to the terrestrial hills and vales. Again it has 

 been declared that the ocean bed is level ; but we find raised portions, which 

 we call islands, which may be the tops of mountains, or portions of the 



