examination, and it became desirable to devise means of bringing up larger amounts of matter. Many contrivances Lave been made for this purpose. Sir John Ross, in 1818, invented a machine for this purpose, called the "deep-sea clamm." A large pair of forceps were kept asunder by a bolt, and the instrument was so contrived that, on the bolt striking the ground, a heavy iron weight slipped down a spindle and closed the forceps, which retained within them a considerable quantity of the bottom, whether sand, mud, or small stones. By this arrangement Sir John Ross brought up six pounds of soft mud from a depth of 6,300 feet.
Fig. 3.
In the year 1854, J. M. Brooke, passed midshipman in the United States Navy, contrived the arrangement known as "Brooke's Deep-Sea Sounding-Apparatus," of which all the more recent contrivances have been to a great extent modifications and improvements, his funda-
