A primary astronomy .. . s, and where the bed of ariver running south from a northern source actually inclined downward; and yet thereare circumstances, as we shall see, under which the above answer is strictly correct.] 286. Can you give an instance of a river running up hill ? The Mississippi is said to be -higher at its mouth than it is some thousands of miles above. [The plausibility of this opinion may be illustratedby a diagram. Let A B represent the polar, andCD the equatorial diameters. The entire differencebetween them is 26 miles, or 13 miles on each two circles represent th
A primary astronomy .. . s, and where the bed of ariver running south from a northern source actually inclined downward; and yet thereare circumstances, as we shall see, under which the above answer is strictly correct.] 286. Can you give an instance of a river running up hill ? The Mississippi is said to be -higher at its mouth than it is some thousands of miles above. [The plausibility of this opinion may be illustratedby a diagram. Let A B represent the polar, andCD the equatorial diameters. The entire differencebetween them is 26 miles, or 13 miles on each two circles represent this difference. Now asthe Earths circumference is 25,000 miles, the dis-tance from the poles to the equator (being one- Afourth of that distance) must be 6,250 miles; and inthat 6,250 miles the ascent is 13 miles, or over twomiles to every 1,000 toward the equator. The Mis-sissippi runs from the 50th to the 30th degrees ofnorth latitude inclusive, or 21 degrees; which, at69£ miles to a degree, would amount to about 1,500. PRLMAEY ASTRONOMY. 63 miles. If, then, it runs a distance equivalent to 1,500 miles directly south (in a wind-ing course of about 3,000), theory requires that it should be about three miles higher atits mouth, than it is 1,500 miles directly north. There is some philosophy, therefore,in saying that if a river runs for a great distance from either pole toward the equator,it must run up hill.] 287. What causes the waters to flow toward the Equator, if theyhave to ascend in so doing? The centrifugal force imparted to them by the Earthsrevolution. (See 280 and Illustrations.) 288. What, then, would be the result if the Earth should ceaseto revolve on its axis? The waters of the equatorial regions would rushtoward the Poles, till the Earth again became a perfectsphere. 289. What would be the effect if the rotation of the Earth upon heraxis was greatly increased ? The waters of the globe would rush toward the equa-tor, and the weight of bodies there would be greatly
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