260 



NEW ENGLAND FARMER. 



Aug. 



body knows the expansive power of water when 

 converted into steam, as it drives the locomotive 

 over the iron road, or the huge vessel across the 

 might)' deep. There is a power in the simple ele- 

 ments of water, far above the comprehension of 

 man, and it is this expansive force that carries the 

 water to the mountain tops. A great raujority of 

 the human race cannot yet comprehend this 

 miglity power. They see the torrent roll down 

 the mountain's side, seeking a lower level, with- 

 out asking how it assumed its high position. 

 Steam is the motive power for carrying water over 

 the land, and steam is produced at nearly all tem- 

 peratures, but the higher the temperature, the 

 greater the pressure. In the language of Prof. 

 Espy, ' all storms are produced by steam power." 

 Silent and unseen are the workings of nature, and 

 yet her laboratory is so vast that the results are 

 tremendous. Were it not for the expansive pow- 

 er of water and its affinity for air, our earth would 

 be a treeless and barren desert. No rivers would 

 ever flow to fertilize the earth, no lakes could ex- 

 ist above the level of the ocean, no clouds obscure 

 the god of day, or bring rain to the thirsty earth. 

 But in the wise economy of nature, all these things 

 are provided for. Air and water possess some of 

 the same elements, and can mingle in one com- 

 mon mass. The warmer parts of earth require 

 more water to fertilize the soil, than the colder 

 parts, and they receive more. The polar lands re- 

 quire but little moisture, and they receive but lit- 

 tle. 



The law regulating the moisture of earth, would 

 indicate the greatest amount of rain at the equa- 

 tor, and the least at the poles ; but another theory 

 steps in and tells us that water is expansible by 

 cold as well as beat, and that steam is produced 

 by the expansion, from the temperature of 08° 

 both upward and downward, consequently the 

 least amount of rain would tall in tliat latitude 

 where the mean yearly temperature is about oS"^, 

 while the amount would increase from that point 

 to the equator, and from that point, though per- 

 haps imperceptably, to the pole. But this line is 

 so variable with the seasons, that no such line ac- 

 tually exists, except as theory. The point of 38'^ 

 temperature is probably about 52° latitude, while 

 at the equator it is in the vicinity of 90°, and the 

 temperature sinks at the pole to about zero. 

 This would give a trifle more at the pole than at 

 52* north latitude, while the amount at (he equa- 

 tor would be enormous. But local causes operate 

 to distribute the rain so unequally, that it is im- 

 possible to give rules which will apply to all parts of 

 the earth, without a vast many exceptions. In the 

 peninsula of Hindostan, the amount of rain is 

 enormous, perhaps greater than in any other part 

 of the world ; yet in South America, it is but lit- 

 tle less. In the vicinity of the ocean, as a general 

 rule, more rain falls than in the interior of conti- 

 nents, yet the evaporation is much greater, for 

 evaporation carries it into the interior, where 

 another distribution takes place. 



All parts of the earth are watered according to 

 the necessii'ies of the soil, except those places 

 which are aff'ected by local causes, such as the des- 

 erts of both continents, for if the soil does not re- 

 ceive suflicient moisture, it soon becomes partially 

 or wholly a desert. No part of the earth becomes 

 a desert except from local causes, as far as mois- 

 ture is concerned. The want of heat as at the 



poles, and, in some of the highest mountains, 

 makes these places an icy desert, with a tempera- 

 ture much too low to produce vegetation. We 

 know Dr. Kane speaks of snow and rain in the 

 Arctic regions, for such is necessary to supply the 

 vast amount of ice and river water in those re- 

 gions. Were this not so, the entire country would 

 be a barren waste of earth, far too cold to sustain 

 animal life, for it is a well known fact that hu- 

 midity lessens the extremes of heat and cold. In 

 the deserts, the heat is unalterable, yet were the 

 amount of moisture increased to the amount due 

 to latitude, the heat would also decrease ; and 

 were not the Arctic regions well supplied with 

 moisture, the cold would be far more intolerable 

 than it is at present. Perhaps some may say, this 

 is a strange doctrine, that a vast body of ice will 

 mitigate the cold, but it is even so. I know not 

 v.'hat degree of cold, water is capable of receiving 

 at the surface, but the heat in the ocean, increases 

 downward, leaving the coldest sheeted water at 

 the top, which is much warmer even when covered 

 with ice than the land. 



Dr. Kane remarks : "The temperature on the 

 poles was always somewhat higher than at the 

 inland, the difference being due, as I suppose, to 

 the heat conducted by the sea-waler, which was at 

 a temperature of 29" above zero, the suspended 

 instruments being aff'ected by radiation." 



This was on the I7th of January, 1854. On 

 another page, he says : "Upon the ice floes, com- 

 mencing with a surface temperature of 30° below 

 zero, I found at two feet deep a temperature of 8", 

 and at four feet, 2" above zero, and at eight feet, 

 26*^ above zero. This was in midwinter, on the 

 largest floe in the open way off Cape S'^affbrd." 



Thus the temperature increases rapidly as we 

 descend into solid ice, being 50 ° warmer eight feet 

 below the surface in solid ice than at the surface. 

 At this rate, one foot more will carry it above the 

 freezing point, where ice would cease. The ice it 

 appears is not continuous, l)ut is broken into large 

 fields, with many flaws and holes for the escape of 

 steam from below. This vapor freezes quickly and 

 descends again in the form of snow, keeping the 

 ground always covered witli snow and ice, which in 

 summer thaws and flows off" in rivers to the ocean, 

 thus keeping up a balance of the watery element 

 in these cold and inclement lands. 



If water did not expand in freezing, ice would 

 be formed at the bottom, or at any rate, w-ould 

 sink to the bottom, so that no ice would ever float 

 on the surface of water, because it would be heav- 

 ier than the water below, and the polar regions if 

 frozen at all, would naturally freeze at the bottom, 

 or the ice would sink to the bottom, so that the 

 surface would be the last to freeze. 



In most parts of the earth there is a surplus of 

 water, which is continually carried off" by rivers to 

 the ocean, which keeps up this balance of the wa- 

 tery clement. All this water is brought from the 

 ocean in the form of vapor, and scattered over the 

 land by the winds. There is, so to speak, an 

 ocean of water in the form of vapor suspended in 

 the atmosphere, ready at the call of the thirsty 

 earth to fulfil its mission. Then from what source 

 does our continent draw its supply, to feed the 

 father of rivers and the mighty lakes, and all the 

 minor streams wliich are continually rolling their 

 tide of waters back to the ocean, carrying off" a 

 portion of earth, and leaving it in the form of sed- 



