The microscope has solved these mysteries. The rains of blood are merely stained by earthy matter: sometimes organic, gathered by the wind; sometimes volcanic dust, thrown out by eruptions; and in one case, where numerous blood-spots appeared on houses and fences in Provence, in 1608, and the priests asserted it was the work of the devil, the spots at length proved to be the excrement of butterflies. Rains of melted sulphur have been found to owe their color to the yellow pollen of pine trees. Ink is merely sooty rain-water. Showers of this character are more frequent than might be supposed. More than a score have occurred in Europe in the present century; and a number in this country. Red and green snow owe their color to microscopic vegetable life, and are quite commonly met with in the Arctic world. One bold headland has long been known as Crimson Cliff, from the extensive deposits of red snow there.

CHAPTER XIV.
FLOODS IN THE SOUTH.

“ ‘Mother dear, the water’s coming after!
Mother, ’tis between us and the hill!’
Looking down, they see the flood, with laughter
Lapping idly ’neath the window sill.
. . . . . . . . . .
‘Mother, in the water we are wading!
Mother, it grows deeper as we go!’
‘Hasten, children! hasten—day is fading!’
Higher creeps the river, black and slow.
. . . . . . . . . .
‘Mother, ’tis so deep, and we are dripping!
Mother, we are sinking! Haste, oh haste!’
In her arms uplifting them and gripping,
On she plunges, wading to the waist.
. . . . . . . . . .
Flowers the river snatches, while it calls so—
Flowers its lean hands never snatched before,
Will it snatch these human flowers also,
Where they cling, sad creatures of the shore?”

VERY country is confronted with a serious problem in its great rivers. In some lands the only problem is, how to get rid of flood-water as quickly as possible: in others, comes the additional question of securing sufficient water for irrigation during the dry season. Egypt occupies an anomalous position, the latter question being the only one of any practical interest. Without rains, she depends on the rise of the Nile for her existence, and no one dreams of such a thing as endeavoring to check the overflow. During seed-time the fellaheen may be seen sometimes in mud knee-deep, busily planting their fields; and in summer they may be seen hoisting water from the stream and emptying it into their irrigating ditches.

In our own land, we have hitherto had no need of irrigation, except in those districts where there is no fear of a flood: such as the arid regions of our southwestern states. In China, the people are contending with both sides of the problem; and their success in the second feature has not greatly surpassed their achievements in the first. In most other lands, the flood problem is the chief one. The Amazon at flood time rises from sixty to one hundred feet, and its volume is almost inconceivable. But since the larger part of its course lies in an almost uninhabited region, the high water gives no concern to the people. The Orinoco rises so high, and is in such a level region, that during part of the year one of its upper tributaries flows backward and reaches the Amazon.

The great length of the Mississippi and Missouri present the gravest difficulties. The sources of each lie in regions where heavy snows fall during a considerable part of the winter: and all the melting snows of the central portion of the country—from western Pennsylvania to Colorado, Montana and central Dakota—must find their way to the sea by way of the single stream. By reason of the difference in latitude and altitude, the melted snows of the head-waters usually swell the lower river in May and early in June, after the spring rains are over. But it quite often happens that after unusually heavy winter snows the warm weather sets in in the mountains very early: so that the great floods of the upper valleys reach the lower river just when extremely heavy rains are prevalent in the central and southern regions. This forms a combination that is terrible to combat, and is the cause of all the trouble. The present system is effective in ordinary cases; but for the occasional great exceptions it has hitherto proved insufficient. We do not seem to be any nearer a practical solution of the problem than when it first presented itself. Yet, the government of the United States spends millions of dollars every year in attempts which have, so far at least, proved totally futile to confine the great river within its banks, and so avoid the perils which every spring threaten an area larger than all New England and the Middle States.

The wonderful and often terrible changes that come with the changes of season, and which produce such effects as the illustrations show, are simply inconceivable to one who has not seen them. That a stream so quiet and comparatively small as the Mississippi is at low water, should become a raging torrent of twenty miles average width, and ten feet average depth from shore to shore, throughout the eleven hundred miles from Cairo to the sea, is simply incredible until one has seen it. This river, however, did that in 1882, when the great general overflow occurred. Unnumbered lives were lost that year, and the damage to property was never even estimated. Details were hard to get when communication was so nearly cut off as it then was; and after the floods were over, no effort was made to reckon the extent of the disaster.

Since that spring the reports have not indicated any flood equal to the present one; and the only reason why this year has not proved as disastrous as 1882, is that the levees have been strengthened since then. The fact, however, that the levee system has, as a whole, successfully withstood the pressure of the highest water known for many years, is by no means as reassuring as it seems on first consideration; for there is grave reason to believe that the levees themselves serve to increase the very danger against which they are a guard.

The planters of the earlier days made efforts to protect themselves by means of “levees:” a name given by the