OCR Text |
Show Cause -of Ocean Titles. 1 Tides aro caused by the gravlta I tlonal nttrnctlon or pull of tho sun and moon upon tho- water, and upon tho earth Itself. Tho moon being so much nearer than tho sun, Is, ot courso, tho principal cause. When tho moon Is directly over a given placo it pulls tho wator uudcr It, and thus tends to keep up a tidal wavo Just under tho moon. At tho samo time It Is putting the earth Itself; but It pulls tho wator moro than tho earth underneath, simply becnuso tho moon Is nearer to tho water on tho surfaco than. It Is to tho solid earth behind It. |