TRANSACTIONS OF THE SECTIONS. Lyall 
the centre wire gives a true level gauge; and the sun or other object being brought 
into contact by the radius bar of the sextant, the altitude is necessarily obtained. 
The telescope occupies precisely the same position as that used in any ordinary 
sextant; and practice, even at sea, soon renders the operation easy. On shore, 
where the sextant can be used with a stand, it will be found very useful for mea- 
paki altitudes of objects of small arc, which could not be reflected in an artificial 
orizon. 
On a Mode of rendering Timber-built Ships Impregnable and Unsinkable 
under Moderate Crew Power, as in Leaky Vessels. By Admiral Sir Epwarp 
BELCHER. 
Referring to a pamphlet by Mr. Walters, who proposed to effect his object by 
introducing copper cylinders between the timbers, the hold-beams, and indeed 
every opening where cargo did not prevent—calculating that these displacements 
or cells would about compensate for difference of specific gravity between cargo, 
vessel, and gear, so as to simply reduce her to the state of a water-logged craft, to 
save crew, vessel, and such portions of cargo as might be secured in air-tight 
yessels—the author stated that the pneumatic trough had suggested to him the 
propriety of close sealing the holds, or underplanking the hold-beams, and saving 
those spaces between them for the storage of light dry goods above that deck 
(which was generally lost), and placing loose planks as a temporary deck. In the 
event of a dangerous leak, or even a large hole being stove in the bows or bottom 
of a ship, he proposed securing the hatches from beneath to hatches above, screwed 
firmly in opposition to each other, and filled in by pitch from the upper or open 
hatch. It would be apparent that, if the ship was air-tight, the water could only 
enter so long as the air was compressible ; and, by inverting the pump-boxes and 
rendering them air-pumps, the leak would not only be stopped, but, by the con- 
tinued action of the air, it would be expelled by the very orifice by which it en- 
tered. Therefore the customary and continued labour and wear of the power of 
the crew would not be required to such an extent, if at all, when once the neces- 
sary quantity of air had been forced in. 
On the Decortication of Cereals. By Roserr Davison. 
After giving a description of the structure of a grain of corn, the author showed 
the advantages that are to be obtained by decortication ; he then dealt with it in 
a hygienic point of view, and detailed the several qualities of bread made from it, 
and furthermore stated that it is better to make a quality with al/ flours united, as 
in this way can a wholesome and well-flavoured bread be best obtained. The 
author then stated the principle adopted by Mr. Poissant (the pioneer of this 
system) in order to obtain the complete decortication. He observed, as a singular 
and important fact, that corn having undergone this process was not so likely to 
be attacked by that destructive insect, the weevil—that is, if the corn is carefully 
excluded from the sunshine. The author thus concluded his paper:—1l. Decorti- 
cated grain will always be profitable to the world, as it incontestibly yields 10 to 
12 per cent. more flour than ordinary millering. 2. It can be done in either 
small or large quantities, and not only produces from 10 to 12 per cent. more flour, 
but at the same time from 5 to 6 per cent. more glutinous nourishment. 3, It 
renders corn safe from the attack of the weevil, and therefore renders it more fit 
for storing against periodical seasons of scarcity. Lastly, the machines are simple, 
cheap, lasting, and capable of being worked either by hand or motive power, at 
small cost; and the system has, in fact, no known drawback, except that pollard, 
bran, &c., which are produced by the present method of millering, will no longer be 
an article of commerce. But, as a set-off, the pellicle which}is produced by the 
new system is found to make an excellent vellum-like paper, which is largely 
sought after in France by bookbinders. 
