300 ANNUAL OF SCIENTIFIC DISCOVERY. 



Magonnerie bon Dleu (God's Masonry), as the negroes of the French colonies 

 call it. In consideration of these facts, the first part of our question may be 

 answered in the affirmative. 



But whether the whole coast is constantly and gradually rising (as we 

 know is the case with the coast of Sweden), or whether those different layers 

 of that submarine pavement have been thrown up at various periods, by 

 sudden volcanic agencies, I am at a loss to decide, from my own observa- 

 tions. I will only state, that the layers which lie now just above low-water 

 mark, are (for instance, in some places in the neighborhood of Jeremie) 

 quite undisturbed banks, running in a plain parallel to the level of the sea. 

 This seems rather to favor the idea of a gradual rising than of a sudden up- 

 heaving, and the latter would be more likely to fracture the layers and to 

 change their original horizontal position into an angle towards the horizon. 



I conclude, from the information afforded me, that this limestone forma- 

 tion must extend over the whole northern part of Hayti, from its western 

 cape (Tibouron) to the neighborhood of Port-au-Prince. Further, the rocky 

 part, of the sea-shore of Barbadoes, Maria Gallante, of Grand-terre in Guada- 

 loupe, of Antigua, St. Bartholome, St. Martin, Arguilla, and Santa Cruz, 

 seems to be of the same composition and age. 



The great respiration of the ocean, the ebbing and flowing of the tide, 

 hardly touches that coast. Neither the native fishermen along the coast, 

 nor the American captains in the harbor, speak of high and low water there. 

 The great tide wave is not only broken by the wall of islands in front of the 

 Mexican Gulf, but, perhaps, is even neutralized by a continual current, which 

 runs from east to west all along the northern shore of Hayti. 



All the motion of the sea on that shore depends upon the wind. Its agen- 

 cies are twofold; first, the daily change of sea, and land wind, the former begin- 

 ning to blow in the morning about eight o'clock, the latter in the even- 

 ing, between six and nine. The latter is much more constant, and being 

 also more powerful, it depresses, every evening, the level of the sea all 

 along the coast, from one to two feet. But there is, secondly, another, a 

 yearly change of the irinds, viz. : a prevailing northerly wind in winter, partic- 

 ularly in December, January, and February, and a prevailing southerly wind 

 in summer. This great change produces this effect, that, in the season of 

 the North, as they call it there, the level of the sea is constantly, on the 

 average, eight feet higher than in the summer. 



How much this change bears, also, upon the organic life of the sea-coast, 

 is evident. I will only state, that, during the last of May and the first of 

 June, in one place not larger than an acre, more than a hundred Actineae 

 and Holothurise died, because left upon dry land; not to speak of the thou- 

 sands of other animals, fishes, echini, etc., and of sea-plants, which died in 

 those natural basins near the sea, where the water, cut off from the refreshing 

 ocean, was overheated by the nearly perpendicular rays of the tropical sun. 



* 



CLASSIFICATION OF THE METAMORPHIC STRATA OF THE ATLANTIC 

 SLOPE OF THE MIDDLE AND SOUTHERN STATES. BY PROF. H. D. 

 ROGERS. 



* 



The following is a concise sketch of the Geological composition of the 

 Atlantic Slope of the Middle and Southern States, derived chiefly from a 

 study of the formations of this portion of Pennsylvania. 



