Captain Hall on laying down Ships' T'rachs, 
’ In order to prove that this ship was lost for want of a time- 
keeper, it is only necessary to state the following facts, which 
will be conclusive with every practical navigator. 
By means of good time-keepers, I found that his Majesty’s 
sloop Victor, during the interval above mentioned, was carried 
by the current 186 miles to the westward, and 7^ miles to the 
eastward, making an aggregate of 114 miles, or S'" 18' of west- 
ing more than the dead reckoning. Now, it would have been 
a moderate allowance for the effect of the Cape current, under 
all the circumstances of the case, to have supposed the ship to 
be set to the westward in eleven days, at least 220 miles, or 106 
miles more than the ship was actually set. So that after the 
Commander of the Arniston had made all the usual allowances, he 
would still have estimated his place wrong by at least 106 miles^ 
or 2° S' of longitude, an error five times greater than the worst 
chronometer I have ever seen in use, would have given in so 
short an interval. It thus becomes certain, that when the Ar- 
niston was, by dead reckoning, after full allowance had been 
made for current, apparently many miles Avest of the Cape, she 
was in fact a very long way east of it. And the important cir- 
cumstance to be borne in mind is, that had this ship been 
provided with a very ordinary chronometer, costing from 60 to 
100 guineas, she Avould, according to every principle of navii^ 
gation^ most assuredly not have been shipwrecked. 
Art. XII . — Account of a new Arrangement of the Algce hy 
H. Christ. Lyngbye. 
1 HE Algae or U'ue aquatic plants, including the various 
tribes of F uci, Ulvae, Confervae, and TremeUm, fonn a very beau- 
tiful department of the botanical system. Of late years, much 
attention has been bestowed on the investigation of their struc- 
ture, physiology, and distribution ; and many curious facts and 
arrangements of Nature have thus been brought to light. 
Their systematic arrangement, which appears to be attended 
with many difficulties, has been greatly studied by naturalists 
since tlie time of Linnaeus and Gmelin, but hitherto no satisfac- 
tory method has been proposed. Dr Walker, late Professor of 
