460 
LORD AUCKLAND'S SCIENTIFIC PARTY. 
by steering where other feelers, still remain- 
ing vertical, shew the channel to be clear. 
** The small paper tubes on the tops of the 
feelers shew where lanterns might be placed, 
throwing out sufficient light ahead, and 
rendering every motion of the feelers con- 
spicuous, if the river were navigated at 
night as well as by day. 
“ If it were necessary, a man or two could 
be stationed before the cross-bar where the 
figure of a boat (3) appears in the model, to 
see that the machinery keeps in order.” 
Several of the scientific and nautical gen- 
tlemen who examined the model at the Go- 
vernment House suggested partial objections 
to the use of the apparatus. Its great 
length, one observed, would probably im- 
pede the vessel in turning to either side. 
Another remarked that, though the long 
shaft could now be taken off and put on 
again at pleasure, it was not sufficiently un- 
der command while attached to the bow at 
the water line. To obviate these inconve- 
niences, the same gentleman proposed to 
let the apparatus down to the water from 
the foremast, or from a sort of crane by 
which it might be placed in its proper posi- 
tion or lifted up as circumstances should 
require. A third, whose knowledge of 
steam navigation gave particular weight to 
his opinion, thought the contrivance unob- 
jectionable in ascending the river at the 
aate of 3 or 4 knots an hour, but not cal- 
culated to be of any use in coming down, at 
double that speed or more, when the warn- 
ing given by the feelers would not be suffi- 
cient to enable the steersman to avoid the 
shoals in his way. 
To these and other remarks the inventor 
replied to the following effect, in the course 
of the conversation which took place. 
With the exception of the metallic rods, 
each a quarter of an inch in diameter, which 
are to form the immersed portion of the 
feelers, the whole of the machinery is in- 
tended to be so light as to float on the sur- 
face like a blown bladder. Having the least 
possible hold on the water therefore, it will 
scarcely be any impediment to the move- 
ments of the steamer. 
Were the long shaft of the apparatus ex- 
tended from a mast or crane elevated above 
the deck, the height would, in addition to 
the present length of it, cause the feelers to 
describe the arc of a larger circle, rising 
higher and sinking deeper than the keel in 
the pitching motion of the vessel. It might 
be an improvement to attach the shaft by a 
long fork to the middle of the vessel on each 
side, at the water line, where there is least 
motion. 
It is not generally believed that the velo- 
city of a body through fluid renders it more 
difficult to turn aside, or a ship less obe- 
dient to the helm. It is not meant that the 
paddles should be backed or the steamer 
stopped, when the feelers indicate a shoal 
in her way. When they shew the exact 
spot where the danger lies, and at the same 
time let us know where there is enough of 
water, turning the rudder a few points to 
larboard or starboard, will apparently make 
the steamer take a safe course the more rea- 
dily the faster she is going. 
No objection seemed to be urged against 
the principle of the contrivance, the doubts 
expressed having reference chiefly to the 
manner of employing it. Dr. Ranken ex- 
pected to find that so simple and obvious a 
means of sounding the bed of a river had 
already been tried and rejected by practical 
men for reasons which he could not disco- 
ver. But this appeared not to be the case, 
and adverting to the great importance of 
being able to navigate the rivers of this 
country with safety in the night as well as 
the day time, he offered to place a complete 
apparatus at the disposal of any competent 
person who had inclination and opportunity 
to give the contrivance a fair trial. 
Mr. Prinsep and Dr. Weifer exhibited the 
powers of the ox-hydrogen microscope, 
by which sections of wood, the structure of 
plants, forms and dispositions of cellular and 
vascular tissues, and fibres of plants, as well 
as organic fabrics, cotton, &c. were accu- 
rately developed. Entomological descriptions 
