TRANSACTIONS OF THE SECTIONS. 
1G1 
means have yet been invented of joining pieces of wood together so as to give them 
the same strength as the whole timber. This want of material of sufficient size 
*as supplied by using iron, for the joints can be made as strongly ns the whole 
r'ate, or plates of metal of any required size can be rolled for the purpose. 1 his 
’•lity of increasing the size of the material is the principal advantage derived from 
•5*tse of iron, which affords facilities far COMtrttCtil g ships of nny si/c ; and 't is 
( t-at material that the great ship, now building in London for the Eastern Steam 
nllrrt. P,...,._ ’ »- 1 - - _.» Ar | M.. rmiinllmpntpfl Mr. Hr unci 
function of large iron ships; and he alluded to the torcoonmgs ui ui*n*u-i u.. 
■^r occasions, when the ‘Great Western' and the ‘Great Britain’ were built, 
'‘kb forebodings events had shown to bi groundless; anti he felt confident that 
lD similar forebodings which some people had expressed of the still larger ship 
u " being built would be equally fallacious. Mr. Bussell said he wished it how¬ 
-to be understood, that he did not reconnnen.l the general adoption of such large 
** ze the ships ought to be suited to the traffic and the distance ; but 
P° lnt be contended for was, that it is only by employing very large ships that 
^ ^-navigation to distant parts of the globe can be profitably carried on. A 
•••an-ahip to Australia, if it were not large enough to carry sufficient tend for the 
had to take in a supply over and over again, and at each station the cost of 
ai, i Was “HCWfWed by conveying it. to the different stations. Under such disad- 
kwa 68 n ° frci gbt could pay the cost of conveyance; and in order to remove them, 
« necessary to build a ship of sufficient size to carry a supply of fuel for the 
t, ; - 0ut anti back again, or equal to circumnavigating the globe. An extremely 
"'ranee was another of the characters which the large ship now building would 
,.| nr - ‘ 6 ? as to enable it to move through the water with the greatest attainable 
^Pfcted'Iw a ' nodarate amount of steam power. With these advantage* it was 
tii, e j at the ship would accomplish the voyage to Australia in thirty or thirty- 
indwoulu It: Wou| ' 1 easily carry 6000 tons, besides its requisite quantity of coal, 
til ,3 ana In° excc l ,e ntaccommodation for 500 first-class passengers, COO secoml- 
: "-tdthof u ° third-class passengers. It would be 6/5 feet long, 85 feet in 
lrurill i n .. beatt !‘ “fid Go feet deep; aud though so large that St. George's Mall is 
the smallest size that could do the work required with 
(economy. 
Mechanical Appliances on board Merchant Ships. By Mr. Saxby. 
Principles and Measures on which Safety in the Navigation 
h. g ma y be reasonably looked for. By the Rev. Dr. Scores by. 
r,,n ipass 5 cs < bv\u^ ded bis previous communications on the deviations of ships' 
^i iAr iencj ne , ? "'lienee of the masses of iron in iron ships, and said, that after 
a Bcnt|(, Ca °PP 0 sit ion, his views had been fully confirmed by Mr. Archibald 
, I* r >ucipi es . , man 'yh° had at command all the records of her Majesty’s ships. 
J; ^at the ™ WLl . ch 1,0 contended were 
W avettic^T ' roa B bips in its action on the compass may be repre- 
ijl' ^>at chanpp a ,a i a horizontal bar swinging round a compass. 
^ bj^ce. ° * m *he magnetic distribution and compass action in iron ships do 
>i ^ at th erc 8 e a 8 r ta - 7 lacc ' Q a ship’s magnetism by changes of magnetic latitude, 
^'ntivelvt 1 , u ‘ ?ncC3 in a ship derived from the varieties of form and 
5 ^correctives ° com P as *) of particular masses of iron which may act as 
^■aiid i n c °rreeting the deviation in iron ship* by fixed magnets is 
alter u, '•be twi s 'ti,,° 90u , ern regions aggravates the error. 
7 Tv ^“gnetic net 15 ! ' n< spraining of the iron materials of a ship will tend to 
Oj 8 *’ whilst chanlr th ° COm ‘ ,as8 : and ‘ 
1854 . ar, ly i' renni r ^ eS f - are not nnfrequently rapid on occasion of blows from the 
. es time to effect the changes in a ship’s magnetic action. 
11 
