The Liverpool Standard, and General Advertiser.
Liverpool, Merseyside, England, 1854-09-26 00:00:00

TUESDAY, SEPTEMBER 20, 1854.

compasses might vary as much
as two, or three, or even even four points, he would have
known, of course, that he must place no reliance upon
them. It did not follow, however, that compasses were of
no use, because, under circumstances, they were liable to
change. They might be, and were of great use for all
that. But what he wished to impress upon them was,
that by attempting to adjust a transient influence by a
permanent influence, they were only aggravating error ;
that captains ought always to bear in mind• this liability
of their compasses to mislead them two or three points;
that they should be always looking after their correction
and verification whenever the sun or a star was in sight,
and that, by keeping a compass aloft, as far as possible
from the iron of the ship, they would always have a
standard to which they would be able to refer, and which
he, in his Arctic voyages, had always found to be correct.
Mr. J. T. Towson, secretary of our Local Marine Board,
next read a paper on "The inefficiency of the Aids of
Science at Present in connection with the Compassses of
Iron Ships." Referring to the paper of Dr. Scoresby, he
said he did not dissent from anything that he had said,
but he wished to point out what he believed to be another
source of error in connection with compasses, deserv-
ing their serious consideration. He alluded to the
change that took place in the inductive magnetism of a
ship when she heeled over. In 1846, Mr: Walker, the
Queen's harbour-master at Plymouth, obtained the per-
mission of the Admiralty to examine the compasses of the
Recruit when heeling, and the result was that the error
from this cause was found to amount to nearly one-half
the maximum error experienced when on an even beam.
He believed that many of the errors in the compasses on
board both wood and iron ships, which neither the mariner
nor the compass-adjuster could account for, was to be
attributed to heeling." In the only six cases in which
he had been able to obtain information of the heeling of
iron ships, it had been shown that considerable errors
had arisen from this cause, but these, of course, were not
sufficient to establish a theory. He thought, however,
that the disastrous loss of the Tayleur might possibly
have arisen from this cause. All the tables of deviations
of compasses of ships that had heeled had the maximum
amount of error, arising from heeling, when the ship's
head was directed within two- or three points of the mag-
netic poles, the same being the.point of no deviation when
the ship's beam was horizontal. In all cases the north
pole of the compass had been drawn towards the point to
which the ship heeled. Besides collateral means adopted
for correcting the compass, there were two systems in use
for that purpose. Captain Johnson's system of swinging
the ship and tabulating the results, which was exclusively
employed in the royal navy; and the Astronomer Royal's
method of compensating the compasses, by means of mag-
nets, which was almost exclusively resorted to in this
port. The objection to Captain Johnson's plan was that
the correction was liable to be employed the wrong way
His experience in the examination of about two thousand
masters of merchant vessels had convinced him of the
soundness of that objection. There was a general ten-
dency in practice to come to a wrong conclusion on the
subject. The mariner knew that westerly deviations indi-
cated that the north end of the needle was drawn to the
west, and came to the conclusion that if his compass had
a westerly deviation it must cause an object bearing north
to appear westerly, whereas it would really appear
easterly; and he had known the same- mistake made
on board of the ships of the royal navy... The most for-
midable objection lo the Astronomer Royal's system was
that the magnetic poles of the compensating magnets
were liable to change or to vary in their intensity. Theo-
retically this appeared probable, but he had no well-
established fact to illustrate it. The change of retentive
magnetism deviation from heeling, and the• change pro-
duced by going to the other hemisphere, were defects
common to both systems. According to Captain John-
son's system; however, the amount of original' error was
always exposed ; while by that of the Astronomer Royal
it was concealed from the moment that the• situation of
the compass was determined on and the ship swung. He
had never met with a captain who could tell him the
original deviation of his compass. In the case. of the
Tayleur the deviation of her steering compass was 60 de-
grees, of her compass before the mizenmast 40 degrees.
After a short discussion,

wn that t'

Mr. HOPICINS gave an account of some experiments
" On the effect of pressure on the temperature of 'fusion of
different substances."

Mr. W. FAIRBAIBN read a paper "On the density of
various bodies, when subjected to enormous compressive
force."

Al. FoucAurr addressed the section in French, and
made some interesting experiments, entitled "Nouvelles
experiences sur le measurement de la Terre awmoyens
du Gyroscope."

Mr. C. 13(Room? explained "An easy method= of pre-
paring thin glass 'cells, for microscopic objects."
Mr. C. F. VAILEY gave an account of Improvements
in submarine and subterranean telegraphic communi-
cation."
The section then adjourned.

SECTION 8.-CHEMICAL SCIENCE.

W. A. Miller, F.R.S., presided

Mr. R. WARRINGTON read the first paper,
"On the production of Boracie Acid and Ammonia by
Volcanic Action." Professor GRAIIAM, F.R.S., then made
some remarks "On the Concentration of Alcohol in Som-
mering's Experiments."
Professor J. D. FORBES, F. G. S., read a paper "On the
occurrence and chemical composition of some minerals
found' in the granite formations of the south of Norway,
and' containing the rarer metals and earths." Dr. GLAD-
STONE, Y. R. S., exhibited some experiments "On the
fluorescence of certain iron and platinum salts." Mr. G.
R. Binurr read an interesting paper " On collodion nega-
tives?'

J'.B. EDWA an s, M.D., F.C. S., read a paper "On collodion
photographs of the moon's surface." In connexion with
Mr. T. A. Forrest and Mr. Hartnup, he had.been engaged
during the year in endeavouring to obtain photographs of
the moon, by the Liverpool telescope. The chief difficulty
in their way they discovered to be that the chemical focus
of the glass was about eight-tenths of an inch beyond that
of the visual one. The images they succeeded in produc-
ing have been copied and enlarged, and will this evening
be exhibited through the medium of the• oxyhydrogen
lantern.

Dr. J. H. GILBERT and Mr. J. B. LAWES, F.R.S., read
papers " On the equivalency of starch and- sngar in food."
Dr. FRANCIS WRIGIITSON gave the analysis of the sewer-
age products of Birmingham, &c.

and the thanks of the section were voted by ac‘-
to Dr. Hume. r"CS
During the reading of Mr. JOHN TowsoN's P3Pe ,rocaa
Modifications of Great Circle Sailing," the section
was exceedingly crowded, and the greatest attenties
tb
paid to Mr. Towson's explanations of the diagrlpecbis
which he illustrated his paper. Rear-Admiral .4i in
Dr. Scoresby, and several other gentleraen expre'S`, the
the warmest and most flattering terms their sense
services which Mr. Towson has rendered tot vilizalt
Dr. Cum, read an interesting paper, conbuv
P. Davis, F.S.A., "On the Forms of
Crania." The paper gave rise to a most animated Ancient.oll'

SECTION F.—STATISTICS.
considerable attention. There were present, the Ear`ot
Mr. Thomas Tooke, presided. This section attraetolf
Harrowby, the Archbishop of Dublin, Mr. \Vilnalni3r°
M.P., and many of our local gentry.
Direction
The first paper was on " The Progress and Trade
British Exports, and the Influence Thereon of Free
and Gold," by Mr. RICHA.RD VALPY. the
A paper "On the Effects of Good and Bad Time! ei,Air,
Committals to Prison," was read by the Rev. Jo„,ri f „apse
chaplain to the Preston House of Correction. lue43/110
elicited much interest. After some discusdiscussion,on

were voted to Mr. Clay for his able paper. ostatik
A paper was read by Mr. M`NERNET, entitled the
tics of Poor Relief and Movement of Population n, r,
Hundreds of Wirral, Cheshire, communicated by
Boileau, Bart., F.R.S." pa(
Mr. DAVID BUXTON, principal of the LiverpoO!.,
and Dumb Asylum, read an able paper on " The PP; Age
Dumb in the United Kingdom in 1851. The pap e she
very cordially received, the Earl of Hinnowny si3l-111 120
took a particular interest in such asylums, seeing 'o'

had one been three years in one himself.
SECTION G.—MECHANICAL SCIENCE. ,c.eff
Mr. WILLIAM FAIRBAIIM, WhO presided,
the postponement of his paper " On the Comb
Fuel and the Prevention of Smoke." Mr. C. W not iri
Hams, who was an authority upon the subject, was
good health, and he was anxious to be present• Cow
Mr. NASUMf described a plan of "A Lightniq vas
ductor for Chimneys," which an experieuce of I'
had proved to him was very advantageous. "Os
The PnEsirrEwm read a paper by 31r. J. Sewell,
Boiler Explosions." 0 the
Mr. DAY (for Mr.. Chanter) read a paper riles b,
Economical Working of Steam-boilers and Furri—§eall
the saving of Fuel, with a more speedy command of
when Boilers require. to be Forced." Ag'
Mr. Glnsox described a contrivance for preveiLi stir
cidents in mines, simply by the insertion of a sPu"'
down the shaft. the
Mr. CLAY then read an interesting paper 1-Vroiling
'Large Fly-wheel at the Mersey Forge.' Illhick
311urustrilowiloy

boiler p'
plates there is a certain limit to the speed at Vic'ol3.
the roller should travel; in other words the number of ire 0,311
tions made by the roller are very few when comPareuer
the roller of other descriptions of iron,
necessary in a mill where direct action was require.a, soci
a fly wheel should be constructed of sufficient size
,05,
weight to have, with a small• number of revolu'ks of
sufficient momentum to overcome the ordinary siVe„,tebl
rolling large plates of iron. This could only be "--,tela
increasing the diameter of the wheel to such an em- a
that the rim should have the requisite monienttliv
velocity, of so many feet per minute. With this aacl
wheel has been made of thirty-five feet diameter,, of
weighing about sixty tons ; about twenty-four t°' raa
which is disposed in the rim, which is • tended
aboutt°
in 4.
with a velocity of about 4,500 feet per minute, 3' ,iii g
thirty-eight revolutions. Great care was necessaq'oala
wheel of such magnitude, that the various parts saiiir4
be well and securely fastened together, and after fiebigli
the drawing of the wheel it was submitted to t",feetlit
authority of Mr. Fairbairn, who pronounced it asp„e;ber.
safe at a velocity of 14,000 feet per minute, na!'",,
revolutions 120. Any person desirous of inspectioa, eer
and it Ni-35.theirt
wheel, which is supposed to be by far the largo'',
made, can see it at the Mersey Iron. Works, Liverr°o
Mr. CLAY also read a paper descriptive of frog
Rolling of Taper Iron as carried on at the gerse„ii oalfi
Works." The manufacture of rolled taper iron. —tell"
practised at the Mersey Iron Works, under a „ a
granted to me. The chief use to which rolled tat*: iaie
is at present applied is for ships knees-and fastens g 7 Bto
when it is mentioned that 2,250 tons were made I,asi;',"tarei,
at the Mersey Works, it will appear that the man'
is of some importanc,e. These knees were formerli
by the tedious process of hammering, and it ill
evident that whilst rolling is a cheaper ode of l'otef
tion, the quality will be improved by reason of the o,ess•
uniformity of texture. I now beg to-explain the I,,re'-0,
By referring to the model it will be seen tl-atilli,beco
chinery consists of two hydraulic cylinders place' 0115
the ordinary " hausings," or standards, in which tly
Ivo
are usually mounted; that these cylinders are ate 001
a piston and rod, which slides through the ordinary sf, Are
that retain the upper roll in its place. The cylioue'other
provided with sCiitable valves, by - which water or.lader,
fluid is allowed to enter and escape from the al dye,
The entrance-valve-is an ordinary clack mushrooal f the
which is quite self-acting; it allows or the entrance 0 exit
fluid, but will not allow of its escape. The calce
valve is a valve somewhat similar to the chief
steilt
in Bramah's press, and can be opened to any ei,ose
by the fine-threaded, screws at the back. I will saP'oll4
bar about to be rolled :- the cylinders charge theinoPe°
with fluid through the clack-valve, and the roller„ rhea
the exit-valve as much.as he considers necessary
pushes the bar throughthe roller,. and the pressure voiretii
the upper roll to attempt to rise, the pressure Is ec's se
nicated through the piston rods in the hollow screis ,test
which
stoh9is
taperii waterpgrroaidas
uucaaeli idor. rs-
ee;dno
to the piston in the cylinder, and according to the rleyit.
regularvalve, trotohleliese"
will not, perhaps, on the first attempt,
taper on the iron ; he then alters
through tbed the
the aloee a little 31/4,10,
and, after a few trials, gets the required taper. Se tie
by means of a jam-nut on the exit-valve spindle, fixeS,,ica
valve in that place, and afterwards makes as many 09,r so
of the bar as may be ordered. The management !:be
simple that it is a very rare thing for a single bar o;
spoiled, in fad, the waste from bad bars is no more edia
of ordinary merchant iron, and. the quantity proc.lue I
the "turn," or "shift," is no less than of bar ir°,,lietirS,
have had rolled twenty-one tons of this iron in nine P„,ttitl
and it would take a hammer to produce .a like cln`riiiri,
more than a fortnight, or, in, other words, the (Place of
that can be made in, one mill would equal the Prou„tic sr:
about twenty,forge hammers. It is evident that a''sile3
tide of tapered form may be. made in a similar W3,,l'aiads
as railway switches and points, anchor shanks, mill
and a
(that are tapered to each. end,) springs for carriagt see
variety of other things. The machinery maY Ts",orlo'
almost any day in operation at the Mersey Iron ',coo;
Sefton-street, Liverpool In the course of some_,cici
th
tion.which succeeded the paper, Mr. Clay exPlaia-
the-greatest weight rolled was seven or eight civts.„oos,
The concluding paper was by Mr. Ja.xEs 1‘11°':-00°'
cer
of Belfast, " A Report of Experiments on the
Discs in Water, and on Experiments to be made °ll
trifugal Pumps."

„ruEsDAN

EMBER 26

tieing the
ns on the

Bi: 'lithe Rates of Chronk
....,I!et, Mr. Ilartnup mad,
Zfa_z importance of having
11:191 ascertained and p(
the a. He then detailed the va..-
ou
me il!rDese of ascertaining the different
lie". objections to which they wen
rat.nvext alluded to the difficulties which, up to a compa
4,11 el 7 recent period had been experienced in Liverpool,
4;le:tying those varying rates notified. By the establish-
-o,o_,,,eefthe Observa.tory, however, ample means had been
Ins4,ti (1 for comparing these variations, and
.it had_ been.
lieli"Tanental in obviating the difficulties previously expe
pte,eed,, Chronometers, he observed, are supposed to be
e
bti.4cl with a mechanical apparatus for compen-
kttit- Ta the variations caused by difference of tempp-
tile Stich contrivances as were generally used in
beentaereantile navy were not to be depended on, as had
proved ; in numerous cases ; but when carefully tested, ftt men' rates of variation in different temperatures noted,
efrilifidence might be placed in them. The differences
e in variation he had found to vary in d•—
ants, the same changes in temperature n(
011 4 han eqnal degree. He had made careful observations
talv nndred chronometers, and the results had been ar-
ebserte(l,ll him in tables which' he showed. From the
Boris most and registered, it appeared !hat the
-
advati. "8 m of them had
trati "ages of havl,,e,
ea, he considered 4

Chrono-

careful

1, and pointed

severally liable.

.ent in-

)t affecting

t. so fa