$0 On preserving fresh Water sweet . 
which the interior lining at least should be of such a sub- 
stance as should not be acted upon: by the water, so as to 
become a cause of contamination. Accordingly, on board 
the two ships here alluded to, the greater part of the wa- 
ter was kept, not in casks, but in cases or tanks, which, 
though they were made of wood, on account of strength, 
Were lined with metallic plates, of the kind manufactured 
by Mr. Charles Wyatt, of Bridge street, under the de- 
nomination of tinned copper sheets; and the junctures of 
the plates or sheets were soldered together, so that the 
tightness of the cases depended entirely on the lining, the 
water having no where access to the wood. The shape 
of these cases was adapted to that of the hold of the ship, 
some of them being made to lit close under the platform, 
by which means the quantity of water stowed was consi- 
derably greater than could have been stowed, in the same 
space, by means of casks ; and thereby the stowage room 
on board ship was very much increased. 
The quantity of water kept in this manner on board 
each ship was about forty tuns, divided into sixteen tanks; 
and there was likewise on board each of the ships about 
thirty tons stowed in casks as usual. 
As the stowing the water in tanks was considered as 
an experiment, the water in the casks was used in prefer- 
ence; that in the tanks being reserved for occasions of ne- 
cessity, excepting that a small quantity of it was used 
occasionally for the purpose of ascertaining its purity, or 
when the water in the casks was deemed, when compared 
with that in the tanks, too bad for use. 
The water in thirteen of the tanks on board one ship, 
and in all the tanks on board of the other, was always as 
sweet as when first taken from the source ; but in the 
other three of the tanks on board one ship, the water was 
found to be more or less tainted as in the casks. This 
difference, however, is easily accounted for, by supposing 
