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THE POPULAR SCIENCE MONTHLY. 



POPULAR MISCELLANY. 



The National Academy of Sciences. 



Professor 0. C. Marsh, who, after the death 

 of Professor Joseph Henry, became acting 

 President of the National Academy of Sci- 

 ences, in his address at the annual meet- 

 ing of that body, held in Washington, 

 April 15th, presented a detailed statement 

 of the action of the Academy with regard 

 to the reorganization of the survey of the 

 Territories. He also submitted a report of 

 the progress which has been made in put- 

 ting into execution Professor Newcornb's 

 plan for determining the distance of the 

 sun by measuring the velocity of light. 

 Professor Marsh justly congratulates the 

 Academy upon the unanimity with which 

 the members adopted the scheme for reor- 

 ganizing the surveys, and on its embodi- 

 ment without change in a law of Congress. 

 The Academy, in all its deliberations upon 

 this important matter, was strictly unpar- 

 tisan, and acted without respect of per- 

 sons. Whether the scheme which now 

 goes into execution will lead to better re- 

 sults than the old plan of many indepen- 

 dent surveys, Professor Marsh leaves to 

 the historian to decide. For the purpose 

 of carrying out Professor Newcomb's plan 

 of determining the sun's distance, the sum 

 of five thousand dollars has been appro- 

 priated by Congress ; and the work of con- 

 structing the necessary apparatus will be 

 commenced as soon as the appropriation is 

 available. It is hoped by those who pro- 

 posed this plan that the experiments will 

 lead to a more accurate determination of 

 the distance of the sun than can be reached 

 by any other method known to astrono- 

 mers. 



The Growth of a Continent. The history 

 of the growth of the European Continent, as 

 recounted by Professor Geikie, gives an in- 

 structive illustration of the relations of geol- 

 ogy to geography. The earliest European 

 land, he says, appears to have existed in 

 the north and northwest, comprising Scan- 

 dinavia, Finland, and the northwest of the 

 British area, and to have extended thence 

 through boreal and arctic latitudes into 

 North America. Of the height and mass of 

 this primeval land some idea maybe formed 



by considering the enormous bulk of the 

 material derived from its disintegration. In 

 the Silurian formations of the British Islands 

 alone there is a mass of rock, worn from the 

 land, which would form a mountain chain 

 extending from Marseilles to the North Cape 

 (1,800 miles), with a mean breadth of over 

 thirty-three miles and an average height of 

 16,000 feet. The Silurian sea which spread 

 across most of central Europe into Asia 

 suffered great disturbance in some regions 

 toward the close of the Silurian period. It 

 was ridged up into land inclosing vast in- 

 land basins, the areas of some of which are 

 still traceable across the British Islands to 

 Scandinavia and the west of Russia. An 

 interesting series of geographical changes 

 can be traced, during which the lakes of 

 the Old Red Sandstone were effaced, the sea 

 that gradually overspread most of Europe 

 was finally silted up, and the lagoons and 

 marshes came to be densely crowded with 

 the vegetation to which we owe our coal- 

 seams. Later terrestrial movements led to 

 the formation of a series of bitter lakes 

 across the heart of Europe, like those now 

 existing in the southeast of Russia. Suc- 

 cessive depressions and elevations brought 

 the open sea again and again across the 

 continent, and gave rise to the accumulation 

 of the rocks of which most of the present 

 surface consists. In these movements the 

 growth of the Alps and other dominant 

 lines of elevation can be more or less dis- 

 tinctly traced. It was at the close of the 

 Eocene period, however, that the great dis- 

 turbances took place to which the European 

 mountains chiefly owe their present dimen- 

 sions. In the Alps we see how these move- 

 ments led to the crumpling up and inversion 

 of vast piles of solid rock, not older in geo- 

 logical position than the soft clay which 

 underlies London. Considerable additional 

 upheaval in Miocene times affected the Al- 

 pine ridges, while, in still later ages, the Ital- 

 ian Peninsula was broadened by the uprise 

 of its sub-Apennine ranges. The proofs of 

 successive periods of volcanic activity dur- 

 ing this long series of geographical revolu- 

 tions are many and varied. So, too, is the 

 evidence for the appearance and disappear- 

 ance of successive floras and faunas, each 

 no doubt seeming at the time of its exist- 

 ence to possess the same aspect of antiquity 

 and prospect of endurance which we natu- 



