Exploring the sea-floor 1 海底勘探

Our knowledge of the oceans a hundred years ago was confined to the two-dimensional shape of the sea surface and the hazards of navigation presented by the irregularities in depth of the shallow water close to the land. The open sea was deep and mysterious, and anyone who gave more than a passing thought to the bottom confines of the oceans probably assumed that the sea bad was flat. Sir James Clark Ross had obtained a sounding of over 2,400 fathoms in 1839, but it was not until of deep soundings was obtained in the Atlantic and the first samples were collected by dredging the bottom. Shortly after this the famous H. M. S. Challenger expedition established the study of the sea-floor as a subject worthy of the most qualified physicists and geologists.
100年前，我们只知道海洋是二维平面形的，以及靠近陆地浅水区的深浅不一能给航行带来危险。无边无际的海洋深邃而又神秘，凡是稍稍想过大海海底的人大概都会认为海底是平坦的。1839年，詹姆斯.克拉克.罗斯爵士曾测得海水深度超过2，400英寻；但直到1869年，皇家学会用英国“豪猪”号舰艇进行了几次巡航后，才在大西洋测得一个海水深度，同时能过挖掘海底，取得了研究海底的首批样品。此后不久，英国著名的“挑战者”号舰艇对海底的那次考察，把对海床的研究确立为一个值得一流物理学家和地质学家从事的研究课题，

New words and expressions 生词和短语
navigation
n. 航海
sounding
n. 水深度
fathom
n. 寻（1寻等于1.8米）
porcupine
n. 箭猪
dredge
v. 挖掘
expedition
n. 远征
physicist
n. 物理学家