224 Reports and Proceedings. 



represented on it by depressions of half' an incli, and the highest 

 mountains only about five -eighths, while the Alleghanies would not 

 rise much over one-eighth of an inch above the mean level. Going 

 back to the origin of the present continents, built up of sedimentary 

 rocks, — sand, clay and limestone, — often more or less altered and 

 crystallized; the lecturer described the condition of the primitive 

 globe, a mass intensely heated, but solid to the centre, surrounded 

 with an irregular surface partially covered by water. This, wearing 

 down the crust, would form sedimentary rocks, which softened in 

 their lower parts by the central heat, would permit irregular move- 

 ments of depression and elevation of the superficial crust, consequent 

 upon greater weight in one place, and less weight in another. To 

 this was conjoined the contraction of the whole outer sedimentary 

 envelope of the globe. The action of atmospheric and other agencies 

 in slowly wearing away the earth's crust was dwelt upon, and it was 

 explained that the matter thus carried down into the sea is dis- 

 tributed by great ocean currents. These are due to the different 

 temperatures of the Equator and Poles, but are modified in their 

 course by the rotation of the earth, giving the northern hemisphere 

 hot and cold north-east and south-west currents, and in the southern 

 hot and cold south-east and north-west currents. Besides, there is a 

 great equatorial current from east to west. To these directions all 

 the great mountain chains conform, with some variations from local 

 causes. The lecturer then explained that the history of mountains 

 was the history of continents, since mountains are but portions of 

 continents which have escaped the eroding action that sooner or 

 later breaks down the solid lands. He illustrated this part of the 

 subject by reference to the geology of eastern North America, and 

 showed how in early times the great ocean currents had spread, in a 

 north-east and south-west direction, a vast mass of sediment along 

 the eastern part of the continent, which now forms the great Ap- 

 palachian belt, partly cut away, but still leaving ridges of mountains. 

 In conclusion, the lecturer observed that the field opened by his 

 theme was far too vast for a single lecture, and that he had been 

 obliged to omit many important points which were required for the 

 full elucidation of this subject. 



lY. — The annual Conversazione of this society took place on 

 February 18th. Geology, Palaeontology, Zoology, Botany, Chemistry, 

 Physical Science, and the Fine Arts, were duly represented. 



The President of the society, Dr. T. Sterry Hunt, F.R.S., wel- 

 comed, in the name of the society, the assembled guests, and alluded 

 briefly to the general object of these annual conversaziones. He 

 alluded to the services of their scientific curator, Mr. J. F. Whiteaves, 

 to whose industry and extensive scientific knowledge the society 

 were deeply indebted; and then proceeded to make some remarks 

 on meteors, preliminary to an explanation of the periodic nature of 

 the November meteors ; he defined two classes, the stony or metallic 

 aerolite, or fire balls, and the shooting stars ; the first comparatively 

 rare, and the last very common, and of daily occurrence. 



