1851.] OF THE ROYAL INSTITUTION. 53 
antiquity. They confirm the ideas entertained of the humid climate 
of the carboniferous period, the forests of which we know were con- 
tinuous over areas several hundreds of miles in diameter. The 
average dimensions of the drops indicate showers of ordinary force ; 
and show that the atmosphere corresponded in density as well as in 
the varying temperature of its different currents with that which now 
invests the globe. The triassic hail, moreover, implies that some 
regions of the atmosphere were at this epoch intensely cold; and 
coupled with the foot-prints, worm tracks, ripple-marks, and the casts 
of cracks formed by the drying of mud, these impressions of rain clearly 
point to the existence of sea-beaches where tides rose and fell, 
and therefore lead us to presume the joint influence of the moon and 
sun. Hence we are led on to infer that at this ancient era, the earth 
with its attendant planet was revolving, as now, round the sun, as 
the centre of our system, which probably belonged then as now to 
one of those countless clusters of stars with which space is filled. 
C. L. 
In the Library, were exhibited ;: — 
Marine Worm from Tale-bank Quarry, Wensleydale, Yorkshire 
[presented by F. H. Gabriel, Esq., M. R.1.] 
Transparent Iceland Spar; an ancient Alabaster Canopic Vase, and 
a Vase in marble from Old London Bridge [by Mr. Tennant]. 
Model of Nelson Column, Yarmouth ; Calabashes, Weapons, 
Cloth and Needle from New Guinea, &c. [from the United Ser- 
vice Institution]. 
Grotesque Figure (naturally formed) in Marble [by Mr. Eades]. 
Turn-tables showing various Modes of diminishing Friction [from the 
Royal Polytechnic Institution]. 
Model of an Anti-Friction Wheel-Carriage, &c. [by Mr. Coles}. 
A delicate Balance for Chemical Analyses [constructed by J. W. M. 
Marriott, Esq., M. R.I.] 
Shakspearean Shield (a design for a bas relief by Luke Limner, Esq.) 
and Specimens of Bookbinding [from Messrs Leightons]. 
Specimens of Imitation Ivory [by Mr. B, Chiverton]. 
