48 
Sapindacese, from British Guiana. For a description of 
the Snake-Nut Tree, see Ann. Nat. Hist., vol. v., p. 202 
(1840). 
Mr. Joseph Sidebotham exhibited a cornelian pebble 
with a cavity containing a globule of water, brought from 
the coast of Tuscany. These pebbles are often picked up on 
the shore, and when broken exhibit a crystalline cavity about 
one-third filled with water. 
Mr. Dyer read a Paper entitled “ Notes on the Intro- 
duction of Steam Navigation.” 
Mr. Dyer stated that this subject, being of great importance, 
had engaged many able pens in tracing the origin of the 
several inventions and experiments that preceded the final 
triumph of steam power over that of wind for navigating 
ships ; each writer claiming the honor of priority for his own 
country. It may be useful to state the order in which, 
and the parties by whom the principal attempts were made 
to realise that object. Several letters lately appeared in 
the Times, and were thence transferred to the pages of 
the Engineer, giving a graphic account of the “ first steamer 
in English waters,” the “ Margery, built at Dumbarton, 
by the late William Denny, for William Anderson, of 
Glasgow, and passed through the canal to the Forth and 
thence to the Thames, where she arrived on the 23rd 
January, 1815.” On the authority of Mr. Anderson, then, 
this date is fixed when the first steamboat w T as seen on 
English waters. The first steamboat, the Claremont , was 
started as « regular packet on the Hudson River, in the 
spring of llS07 ; so that the first steamer seen on the 
American waters was fifty-five years ago, a lapse of time that 
should now insure a calm view of the stops that led to this 
first actual success in steam navigation. It will be shown 
that, by a long course of persevering labours, the honor of 
