The Earth as Modified by Human ActionSampson Low, Marston Low, and Searle, 1874 - 656 páginas |
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abundant acres action agricultural Alps American ancient animals annual Apennines Ardèche artesian artificial ascribed atmosphere banks basin Becquerel birds canals century channel character climate coast consequently countries course covered cubic yards cultivated deposit depth desert destruction dikes diminished discharge draining dunes earth effects Egypt Europe evaporation extent fact feet felled floods flow forest Forêts France geographical gravel ground growth Haarlem height Hence humidity hundred hygroscopicity important inches increase influence insects inundations irrigation Italy lake land Lappmarken larvæ less Lombardy lower maritime pine miles moisture mountains natural Nile Northern observations pine plains plantations plants precipitation present probably produced proportion protection provinces quadrupeds quantity rain rapid reservoirs river rock roots sand season snow soil species springs square miles strata stratum streams superficial supply surface sylviculture temperature thermoscopic timber tion torrents trees Val di Chiana valley vegetable wild wind winter woods Zuiderzee
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Página 31 - Man has too long forgotten that the earth was given to him for usufruct alone, not for consumption, still less for profligate waste.
Página 274 - ... twenty-five years previously and planted with Scotch fir. The change in the native vegetation of the planted part of the heath was most remarkable, more than is generally seen in passing from one quite different soil to another ; not only the proportional numbers of the heath-plants were wholly changed, but twelve species of plants (not counting grasses and carices) flourished in the plantations, which could not be found on the heath.
Página 41 - ... would reduce it to such a condition of impoverished productiveness, of shattered surface, of climatic excess, as to threaten the depravation, barbarism, and perhaps even extinction of the species...
Página 370 - It is certain that a desolation like that which has overwhelmed many once beautiful and fertile regions of Europe, awaits an important part of the territory of the United States, unless prompt measures are taken to check the action of destructive causes already in operation.
Página 2 - If to this realm of desolation we add the now wasted and solitary soils of Persia and the remoter East that once fed their millions with milk and honey, we shall see that a territory larger than all Europe, the abundance of which sustained in bygone centuries a population scarcely inferior to that of the whole Christian world at the present day, has been entirely withdrawn from human use, or, at best, is thinly inhabited...
Página 207 - The spot is in the middle of a very steep pasture inclining to the south. Eighty years ago, the owner of the land, perceiving that young firs were shooting up in the upper part of it, determined to let them grow, and they soon formed a flourishing grove. As soon as they were well grown, a fine spring appeared in place of the occasional rill, and furnished abundant water in the longest droughts. For forty or fifty years this spring was considered the best in the Clos du Doubs. A fewyears since, the...
Página 274 - In Staffordshire, on the estate of a relation, where I had ample means of investigation, there was a large and extremely barren heath, which had never been touched by the hand of man ; but several hundred acres of exactly the same nature had been enclosed twenty-five years previously and planted with Scotch fir. The change in the native vegetation...
Página 208 - Dr Piper quotes from a letter of William C. Bryant the following remarks : ' It is a common observation that our summers are becoming drier and our streams smaller. Take the Cuyahoga as an illustration. Fifty years ago large barges loaded with goods went up and down that river, and one of the vessels engaged in the battle of Lake Erie, in which the gallant Perry was victorious, was built at Old Portage, six miles north of Albion, and floated down to the lake. Now, in an ordinary stage of the water,...
Página 280 - ... and sun and . scouring rain. Gradually it becomes altogether barren. The washing of the soil from the mountains leaves bare ridges of sterile rock, and the rich organic mould which covered them, now swept down into the dank low grounds, promotes a luxuriance of aquatic vegetation that breeds fever, and more insidious forms of mortal disease, by its decay, and thus the earth is rendered no longer fit for the habitation of man.* To the general truth of this sad picture there are many exceptions,...
Página 208 - ... the stream itself has been entirely dry. Within the last ten years a new growth of wood has sprung up on most of the land formerly occupied by the old forest ; and now the water runs through the year, notwithstanding the great droughts of the last few years, going back from 1856.