The sun., 1895-02-03

limit the pressure that II will not inturiuusly
strain the fastening, after which the holes are
The following ships Of the British navy have
| been shCnthed IN this way; SeCOnd-clnss rat
tie ships. Centurion and Barneur; hrst-class
| cruisers. Royal Arthur Crescent Gibraltar and
IT, peorEe; cruser7 hstr9s @ rib. 1eS
| ton, Rainbow, Iphigcna, Sirius, spartan In
tIcpid, indcfatlgable, Pique. and Fox; third;
| Blonde. and the sloops Basilisk, and Benglc.
| The sceond;class cruisers Charyhdis, Fiorra,
| similarly sheathed. The other cppper-sheathed
| vessels In the navy Of Great Britain are; The
swiftsure. Trlumph. and Warspite; the unar.
mored cruising ships Active, Alert, Astrea,
Boadlcea. Calliopc, Calypso, Canada, Carysfort.
Champion. Cleopatra Comus, Conquest, Con-
stance, Cordclia, Crescent, CURACAO, Eclipse, 1n-
trepid, MaRiclenne, Marathon. Melpomene,
Minerva, Powerful, Raleigh. Talbot, Terrible,
In continuing the subject of shcnthInc, Chief
Constructor IiiChbOrn says:
The most recent practice In France is cxem-
plheu by the method OF shenthing adopted upon
ShG S GhHn Hen Srsa THsGT Ss sS onpsn p prHt M
teak keel, stem and stern post, and shcathed
with two courses OF plank. he inner, course be-
course OF elm 29S inches thick. The inner course
is fastened to the skin plating by iron bolts, gal
vanized above the thread In wake of the armor
tap bolts OF the same diameter are used, penc-
trating y inch into the surface Of the nrmor.
bronze lag screws ~ H. diameter, OF such length
that the point IN not less than 1-lG inch from
the skin plating. The heads & ct the t2its In the
Of plank, md the heads of the lag screws are
"Thss heads NJ nil fasteninrs are covered with
amixture OF red and white lead; the whole is
then Nhrnthcd with copper. This seems to fol-
low very closely the system formerly In use in
the English service, the only material departures
being the use Of wood kcel stem. and sternpoSt,
and the ralyan2ing of the bolts VI tn" inner
course. The French Admiralty programme for
ten years, beginning in 1891, provides for 0
hrst-class cruisers of which Sarc to be sheathed;
.tstlG
shcnthed. and = third-Cass cruisers, IL of
which are to be sheatcd: or out uf II total of ~
vessels 3f the cruiser class. ~ arc to be
The following nrmorcd steel ships in the
French navy are sh 'athed with copper: Dugucs-
elm. FusGe, Grenade, and Mitraillc and the
unarmored ships Catinat Duchayla Natalie and
"Thc Russian Admiralty" adds chief Con-
structor lichborn. - continues, To = limit cd ex-
tent the practice OF shcathing, requiring the ft-
outer surface OF the skin plating between which
vertical chucks Of wood are wedsed without
botinG, which chocks receive the lng-screw ias-
Jennings OF n course of plank worked oNer them.
The system is very heavy and costly. and IL is
difficult TO see what material advantage it pos
scsses over those more generally used.
In the Russian navy the armored ships Ad-
mirnl Nachimotf, Alexander ll .Dmitri Don
Nice-Admiral Popotr. and Vladimir Monomach
are copper sheathtd. Tho pamyat AZova is
wood sheathed over her armor: The copper
shcRthed vessels uf other naVies are the Bra
lillian battle ships Aquida ban. now undergoing
repairs at Rio de Janelro after being sunk by u
torpedo in the recent revolution, and the Ria
chucIo, the Gillian unarmored ships 'residente
Erra2uriz and Prcsidente Pinto. the Danish
Dutch turrct ship Koningin Wilhelmna der
Niederlandcn.
One serious contingency that cannot be ignored
in the consideration OF steel, copper-sheathed
vessels Is the harm that will result IL, by any
chance, a portion OF the sheathing is torn OFF,
and they are instantly attacked by galvanic
action. When il is known aboard that part Of
tue sheathing has been removed there is nothing
10 be done but to crowd ON all steam and lay a
straight course for the nearest dry dock.
Zinc has been tried, and is still IN use in some
zinc does not act well in salt water. as it pits
and deteriorates very RAPIDLY; In the English
ton. shannon. and Temernirc are zinc sheathed.
as are the Dutch ships Atjeh Bali, De Ruyter.
Van Speyk. and Flamingo.
sought solution Of the problem OF protection Of
Lieut.. J. H. Murdock. United states navy, made |
n careful Investigation OF lacqucring expert:
the work were publ tshcd in the Proceedings of |
the United States Naval Institute, in 1890.
The idea of lacquering iron and steel vessels |
as protection against the action Of sea water"
wrote Mr.. Murdock. was suggested to Mr.. |
observation that pieces OF old lacquer recovered |
from the sea showed but little action, the |
lacquer being practically unattached. As the
ships from abroad. and were encountering the
same difficulties that were met with elsewhere
In protecting the metal, experiments were made
ON special plates which were immersed In
water for considerable periods. generally at tine
were not fully satisfactory. but were very
and the tests were continued, vary
ng slightly the composition OF tho lacquer, or
adding chemicals To assist in obtaining the de-
sired results. In June. 1850. practical test
Hs "4s T1itsm by f"c3rerE sHS GS9 feet
had SiSsn the best results results Io ship p was t docRei
hc lacqucred portion was so satisfactory that
ne Admiralty gave an order to lacquer the
again docked, but the lacquer coat was found to
DC SO good hat no repairs were made. In June.
$50 the ship was again docked the lacquer be-
nG still satisfactory. In each case ant fouling
'aInt was applied over the lacquer. The Fuse
vas doCkcd once more in April. 1880, and
although the lacquer covering was almost per.
cct IL was, for some unknown reason, removed
'y scraping, and the bottom was painted"
since the experiment on the FusO- Kan, many
'ther ships OF the Japanese navy have been
acqpered llotta ~ Co. do all the lacquering,
IS they hold monopoly, under Japamese law
similar TO n patent in this country. The firm
ias also cndtavored to meet all the require
nents of the case 10y providing an anti corrosive
metallic anti-fouling paints over the lacquer
'oat having been found to be injurious.
When shipis to be lncQuered it is docked,
md all yellow rust, old paint, and other slightly
Inherent matters carefully scratched oil. 1t
; not necessary to remove old paint that adj
hen hung from just above the water line To the
loor of thedock 50 completely To shut in the
lottOm or the ship. In case the laCguering is
lone in winter stoves or other heating apparatus
're set up inside the screen to raise the tenn
'crature N order To facilitate The drying of the
oatns Of lacquer In lacquer fac tories exhaust
team L. allowed 10 escape into the wnrkrOOms
or this. purpose, but tho scheme has not been
ried in the case OF ships, although IT
ihS been proposed to let the steam
ape behind the screen. In summer The
ise OF screens is necessary tn protect the
hips plates from the suns rnys, as they might
q raise the temperature OF the metal that the
lcquer would cOaEuRtc. With the screens in
'ace. however, the lacquering process may he
hrricd on i'll almost any condition uf weather.
When the tirst coating of lacquer is applied by
means OF wooden spatulas IL Is worked down
nto uniformly thin coat by repeated strokes
'ilh a nat Camels hair brush. the strokes being
made in different directions, most commonly at
lEht angles one workman can lacquer about
90 square feet in single coat in eight hours.
II" time required for the drying OF the first
oat varies from four or five Eours to n whole
ay. according Go the temperature and the
mount OF moisture In the air. In winter the
rytng occupies n long time.
When the first coat is thoroughly dry the see
nj Is applied in like manner Thls one may
ontaln mica ur kaolln, or some other inert min