May 4, 1899] 
NATURE 
21 
loaded, trained, elevated, and depressed with ease and com- 
parative rapidity under the guidance of a few men. Mr. 
George Rendel was one of the first, as well as one of the most 
successful, workers in the design of mechanical appliances for 
working heavy guns by hydraulic power. Messrs. Armstrong 
have from the first taken a leading position in this class of 
work. Messrs. Whitworth, and, in more recent times, Messrs. 
Vickers, have also undertaken it ona large scale. Hydraulic 
power finds most favour in the Royal Navy. Abroad, electrical 
power is now extensively used. Pneumatic power has been 
employed in a few cases. 
Improvements in gun-design and in explosives have resulted 
in an increased ratio of power to weight in the latest types of 
guns. Asa result, in the latest completed battleships, guns of 
12-inch calibre, weighing 46 tons, firing 850-lb. projectiles, with 
muzzle velocities of about 2400 feet per second, and energies of 
33,000 foot-tons have been used instead of the 67-ton and 110- 
ton guns of early date. These reduced weights of charges and 
projectiles are more easily handled ; and this fact, together with 
certain changes in the system of mounting, have enabled many 
of the operations of loading and working the guns to be per- 
formed by manual power as well as by hydraulic power. This 
duplication is obviously advantageous, and reduces greatly the 
risk of heavy guns being put out of action. There was a time 
when a return to guns of still smaller dimensions, capable of 
being worked exclusively by hand-power, was strongly ad- 
vocated. It was urged that it was unwise to depend at all on 
mechanical power, because it might fail at a critical moment. 
Such arguments are now but little heard. Experience does not 
demonstrate that any serious risk of ‘‘ breakdown” need be 
feared in mechanical appliances. Moreover, the advocates of 
manual power overlooked the fact that, supposing that system 
had been adopted, there must still remain in all modern mount- 
ings and breech mechanisms many comparatively delicate parts, 
perhaps more liable to injury or derangement than the appliances 
which were condemned. 
Steady improvement has been made in heavy gun mountings 
and in rapidity of fire. For example, with 12-inch guns from 
two and a half to three minutes were formerly considered to be 
a reasonable interval between successive rounds; now that 
interval has been brought below one minute, when pairs of guns 
are loaded and fired. Loading has also been made possible 
with the guns in any position, whereas formerly the guns were 
brought to fixed hoists, and to a definite angle of elevation for 
loading. It is most interesting to watch the working of these 
heavy guns, by means of mechanisms controlled by a few men. 
All the operations are performed with rapidity and precision, 
from the moment projectiles and charges are moved from their 
stowing positions in shell rooms and magazines situated deep 
down in the holds, up to the time when they are rammed home 
in the gun, the breech closed and the gun made ready for firing. 
Then one sees the captain of the barbette or turret training or 
changing the elevation of the gun up to the instant when he fires 
by electricity, and the huge projectile is discharged. 
Passing from guns to torpedoes, one finds a fresh example of 
the important work done by mechanical engineers. The in- 
ventor of the automobile torpedo, Mr. Whitehead, is an eminent 
member of the profession. The torpedo itself is a beautiful 
example of mechanical engineering. All the machinery con- 
nected with air compression and storage, all the arrangements 
for ejecting above or below water, involve skilful mechanical 
design. Nor is this all, From the introduction of the 
torpedo has sprung the necessity for special structural and 
defensive arrangements in warships. as well as the construc- 
tion of the swift torpedo flotilla-boats, destroyers, gunboats and 
depot ships, whose performances are not merely remarkable, 
but suggestive of possibilities in regard to steam navigation at 
high speeds. 
The smaller classes of boats using the locomotive torpedo 
have to be carried by warships. They weigh, fully equipped, 
18 to 20 tons, or about three times as much as the heaviest 
load ordinarily dealt with in merchant ships by their own 
lifting gear. This has involved the design of special lifting 
appliances for warships. After long experience in the Royal 
Navy, the most suitable arrangement has been found to be a 
strong steel derrick carried by the mast, with powerful steam or 
hydraulic hoists working tackles which lift the boats and top the 
derrick. Winches or capstans are also used in some instances 
for swinging the derricks. Admiralty specifications require 
that the lifting gear shall be capable of dealing with a load of 
NO. 1540, VOL. 60] 
about 18 tons lifted by a single wire rope, as well as with 
a load of 9 tons raised 30 feet per minute. In one ship, 
the Vulcan, built as a torpedo depot ship and_ boat 
carrier, instead of derricks two powerful hydraulic 
cranes are fitted. She carries six steel torpedo boats, 
60 feet long and of 16 knots speed, besides sixteen 
other boats, some of large size. The total weight of these boats 
1s 150 tons, and they are placed 27 feet above water. The two 
cranesand their gear weigh 140 tons; the tops of the cranes 
are 55 feet above water. It required careful designing to meet 
such exceptional conditions satisfactorily and to produce a stable 
and seaworthy ship. She has now been many years on service 
and has a good reputation. 
Besides these special boat-lifting appliances, warships com- 
monly have special coal-hoists, transporters and other gear for 
the purpose of accelerating the taking of coal on board. 
Rapidity in coaling must be cf great importance in time of war, 
and keen competition between ships in the various squadrons as 
to the rates attained have led to great improvements in details 
of gear, as well as to remarkably rapid coaling becoming the rule 
in the Royal Navy. Recently, at Gibraltar, the M/ajestze took on 
board 1070 tons of coal in 6 hours and 10 minutes—a very fine 
performance. 
All the larger ships in the Royal Navy have engineers’ work- 
shops fitted with a considerable number of machine-tools, 
driven by power, and of sufficient size to deal with ordinary 
repairs. The Vwlcan is a special vessel in this sense also, as 
she has an exceptionally well-equipped workshop, a smal} 
foundry anda hydraulic press for forgings. For repairs of the 
boats she carries, or for those of torpedo boats and destroyers 
in company, or for certain repairs to ships of the fleet to which 
she is attached, the Vu/cax has been found most useful. Besides 
being a floating factory and a boat carrier, she has a large- 
torpedo and mining equipment, an electrical laboratory, and 
serves as a school of instruction for mining and torpedo work. 
In addition, she is a swift cruiser, with a fair armament and well. 
protected. As an armed ship, she represents the fullest appli- 
cation of mechanical appliances afloat. Her construction was 
commenced in 1887. Other navies have since imitated her. 
Another Vuécan was fitted up as a floating factory to serve 
with the American fleet during the recent war. She was 
originally a merchant steamer, but is said to have proved of 
great service. Naval opinion seems to favour the use of vessels 
of this class with fleets. It is held, moreover, that no modern 
fleet can be considered to be complete unless the fighting ships 
are supplemented by ships specially equipped for distilling and. 
storing fresh water, or carrying coals, ammunition and reserve 
stores. 
SATURN’S NEW SATELLITE. 
]N Harvard College Observatory Circular, No. 43, just re- 
ceived, Prof. E. C. Pickering gives the following detailed), 
account of the discovery and observations of the new satellite of 
Saturn :— 
Nearly all of the astronomical discoveries made by the aid of 
photography have related to the fixed stars. In the study of the 
members of the solar system, the results obtained by the eye are 
generally better than those derived from a photograph. For 
many years it has been supposed that photography might be 
used for the discovery of new satellites, and in April 1888 a 
careful study of the vicinity of the outer planets was made by 
Prof. William H. Pickering. Photographs were taken with the 
13-inch Boyden telescope, with exposures of about one hour, 
and images were obtained of all the satellites of Saturn then 
known except Mimas, whose light is obscured by that of its 
primary. It was then shown that Saturn probably had no 
satellite, as yet undiscovered, revolving in an orbit outside of 
that of Enceledus, unless it was more than a magnitude fainter 
than Hyperion (Forty-third Report Harv. Coll. Obs., p. 8). 
In planning the Bruce photographic telescope, a search for 
distant and faint satellites was regarded as an important part of 
its work, and accordingly plates for this purpose were taken at 
Arequipa by Dr. Stewart. A careful examination of these plates. 
has been made by Prof. William H. Pickering, and by super- 
posing two of them, A 3228 and A 3233, taken August 16 and 18, 
1898, with exposures of 120m., a faint object was found which 
appeared in different positions on the two plates. The same 
object is shown on two other plates A 3227 and A 3230, taken 
