How to Gf3uild the CHAPTER VI

By ORVILLE HICKMAN

The editors of J\o10DERN lUECHANICS AND INVENTIONS and , the aimual FLYING MANUAL have consistently endeavored to present plans of light plancs which were easy to huild and withl¥ Ihe price range of the average amateur. Here, however, is a onc-place sport plane, designed especially for the builder who is wUling to spend more money for greater speed and higher ceiling.

LIGHT plane design~rs and manufactur-ers have adhered 50 consistently to the

high-wing monoplane that many persons have come to believe that light plane and mono-plane are synonymous. There are some fans. however. who have 10 insistently demanded a one.place biplane of steel fuselage construc-tion [hat their plea could not be ignored.

In the Powell "P.H." Race r these fans will find a ship that will require skill in building and fl ying, a knowledge of welding, strict adherence to the plans as given, and a real honest-te-goodness aero engine. For one who can exerci&e enough self-control to follow plans to the letter, and who has the price of a good light plane motor, this article will present something that wilt get out and step with the best of them. A high speed of 95 mi les an hour and an absolute ceiling of 14,000 feet can be attained with this little biplane if the builder will give the job the time and money needed on a ship such as this. Those who want to use a two· qlinder motorcycle engine, and who can't do

a good job of weld ing, had better leave the "P.H." alone.

Before we tackle the actual buildini of the plane. let us look around and see what we can use for the power plant. Only one mood of this racer has been built, and it was powered with a Bristol·Cherub motor. This is an excellent little engine for a racing job such as this. as it develops plenty of horse-power for its weight.

The "Cherub" is a British motor. and is distributed by the Aero Engines of Canada, Ltd .• of Montreal. Two American moton have recently been developed which are just suited to such a job as this. These. are the Atronca motor, manufactured by the Aero-nautical Corporation of America of C incin· nati. and the Continental A·40 made by the Continental Aircrah Engine Company of Detroit. Michigan. You will find the Heath Henderson motor a very fine little power plant if economy is what you are after. but the above mentioned hi~her priced engines will give you top perfonnance.

SPECIFICATIONS OF TilE I'OWELL"P.Il." RACER

Lenglh Ovtl'sll .. . ,14ft . Y2 in. Height Overall .... 5 fl. :$ in. SI,all, Upper Wing ... ') 5 ft. 9 in. Spsn, Lower Wing ... 15 ft . 9 in.

Chord, Upper and Lower Wing 32 in. Cap • . . . .• 30 in. Siagger . . . . . . . . . • • 9 ~ in. Air.foil .. . . •.•. . . R. A. F.1S

98

Anglt of Incidence, Upper and Lower . . . . . . . . . . . . . . . . 0

Dihedrsl, Upper Hud f:.ower, 1 degree S pan of Stabilizer . ... . {. ft.

Maximum Speed . .. 95 J11. p. h. (With Briltol ·Cherub Motor)

Cruising Speed ... 80 m. I" h. Landing Speed .. . 32 m. p. h. Ceiling .. ... .. .•• 14,000 fl.

POWELL "~Po H." RACER

99

;i"8

0lT

S ~

OO!

4T

r4C

"'N

G r

.. (

~UHL

"GE

'S ,.

,-H

-9

" "

Sr

... e

ll'Z

EO

! T

U,e

n

SH

O€T,~

, ~6

" 2

1-

. 2

4-

\0....

::: "

0 ':"'"

,

, .

I T

.t '.

!

j "~I

; F

~

! .. t

r ....

. TT

EN

[O

AN

D

OR

ILlE

O

LON

GtR

ON

S

TO

"'

'''C

M

r .. (

""

OT

OR

"O

U"T

'5

"1

T"C

H[0

!l(Z

OG

A

I =

...

...-H

IIU

T

TO

S

UP

PO

RT

R

uD

DE

R

t .

, ...

T

Ull

E f<

l ..... ~

=

C

RO

SS

II

RA

Ce--

....

. I/

__ CROSS

BR

AC

E

r==-

~-..

Lt

\JJ

I V

1.

1-~I

...

~

SID

E

ViE

....

. Sl

OE

OR

.C[ _

__

~ l

__

_ ,

OF

' rU

SE

L A

GE

_

Sl"

~v.l£i

li!i

-L

ON

(;(R

ON

tIllli

t 1-

-+--

'''".

. I

" '9

" 2n

" 2&

-..

2'"

..

2""

• 'O

f---

.

IT' .'

__ '''l~

l' A

ll.

M(I

\SU<

!["

(NrS

G

IVE

N

~

TY

PIC

-'L

T

YP

E

AR

E fR

O,"

C

( ..

l(O

! TO

C

[NT

;::R

or

1u

8($

_

__

O

f W

EL

D

TO

B

E

US

ED

. I 0.

"'_

i!'\ J ~

. -

I J

I, =~~

=:,:::

"" I

I...I2C

"'LUC51O"TT~

TO

P

VIE

W

CENT'","TI~N

5-R

"1S

o

r

fUS

E.L

AG

E

I ..

Y

'Y

,,,'"

'1

'-9

" •

I '-

--14

f '~'

.. '~

r..

34f

.. n

' 2.

'.

IO'--

l I'~

..

11

r --

I I

T

'-+

..

! I

o~

!: ~

~:.

"I I"

i -""",

!,."...

~ _=

=(P

IIO

"'O

( *"

HO

l(

,

I..-

?""-

rOil

AT

tAC

HIN

G

TH

E

r ";s<

rA, .

. $1

'1' .... .,. .. "" II" ... ot the U ........ nr .. """I., .,,,101.,,,1 Joe .....

You will notice that nothing has been said of converted automobile or twin motorcycle engines. Such motors are absolutely unfitted for powering the " P.H. " Racer. the former having too much weight and the btter not enough ho~s.

Now that I have scared off those who hoped to build sometbing cheap from a few odds and ends picked up here and there. we fellows who have the price and want to build n rcal racer will Step over to the corner of the hangar and take up the matter of con-struction. Let us start with the fuselage.

This structure is all sted and is of 0011-ventional design. Twenty-gauge steel tubing. commonly listed as .035 thickness is used throughout. the longerons being Ya" mate-rial, while all other members a re of !tl" diameter except where otherwise specified on the plans. .

The first thing to do is to layout your plan on some absolutely level surface such as a wooden floor or a long table. \-Vhen you are sure that everything is right to the frac-tion of an inch. take two pieces of tubing that arc long enough . for the entire length of the fuselage and outline them over your larout with nails so that they are right over the lines for the longerons.

Now you aTe read)' for the vertical mem-bers and diagonals. The tubes should be cut with a hacksaw so thnt all are in place right to the dot. When this is done. spot weld all of the fuselage side together. Now make the

Gild." Manila'

other side just like the first and spot weld it too.

We are now ready for the most particular job of the entire fuselage construction. H av-ing satisfied ),ourself that your ROOT or table is perfectly level. layout the top plan of the fusel age and cut these pieces to the proper size. Then using nails or some other sort of jig to hold the members in their proper places, place one side of the fuselage. with the top longeron down. in its proper place. forming it around the lines you have already laid down. using a square to get the side ahso· lutely perpendicular to the floor or table. Now do the same with the other side and spot weld the cross pieces and diagonals in place. The jigs will hold the work while you are welding it.

Now layout your bottom plan. invert the fuselage and square it UI) as before. cut your diagonals and cross piece$ and Spot weld them. After making sure that rour struc-ture is still S(luare you can cut and spot weld the internal diagonals. and will then be ready to weld the fuselage together.

This welding must be done by a man who thoroughly Ir:nows his job. If ),Oll don't feel competent to tackle this most important taslr: you can hire a welder to come to your shop. An experienced man should hl: ahle to do all of the cutting and welding in two dars at the most. Of course this will cost rou more than if you did the job )'ourself. but if you have to make a forced landing

101

, .. :0-1 SIDE VIEW

OF" LANDING G

rx 11 GAGe $T .. t: .......... 'N'" TU&INC I"OA

,

==~;e~A;"'OING CE"'~ 7 ~TRUT5

.. l'!O· :n:c f"U:5£I.AC£ PLAN

'B-x 3- WHetLs AND TUtl::5

180LTS

DETAIL OF AXLE END • ~-RI!Q'O.

V"RCAO(R 6A.A5 ARI: J-x itO

BOTTOM VIEW OF SPREADER BARS AND AXLE r TtiE AXLE 1:5 ,-x 1'2 (;". C"''''.O'''I: VANAOIVIooI

I.._-d-.>C"T

DETAIL OF STRUT L.1JG

a " U!:Q' D 11 CA

DETAIL OF ATTACHING STRUTS TO FUSELAGE ORI"-'- ~ HOL..I:

'OR TI)'ItN9UC:I\L£ PON

IW,e'''NG'OETAIL OF ATTACHINC SPREADER BAR AND LUG

..... THE COMPLETE LANDING __ -4-GEAR ASSEMBLY--

LUG I ... C A

()f ~ ... eldln .. h. n ee,led here.

102

' I'loe ...... U .. I!J" ",e.r ... one 01' th., ... oat ...... 0 .. _

t ...... " ... t .. or r .. n .. ,.I.ue ........ ne or the ..... .-d_ .... t to build, Full detan .... re .hon' " her ...

(and who docsn't at one time or another?) it's a great satisfaction t o L::now that your fuselage isn't going to com e apart at some critical point. vVdders demand good money for their labor. hut it seems paltry beside;> ,,~hat .1 doctor or undertalcer can charge.

Start welding from the front end a nd go around the f U!l:e1 age. worki n g to\vard the tail. J n this way you chase out all the kinks and warps that would develop if you wen t at the job in a hit and miss manner.

Now- that you have the st ructure com -pleted let us put on the lugs for the landing gear. ~nter section struts. flying wires. and the tail group. 'rhese nre all made of I 3 gauge steel ~" wide and I" long_ They are put in their respective places and weld-ed on (see Figure 2). After all of these fittings are in place. the entire fuselage should be treated to a good coat of lionoil.

The mOlar mount is not given in d etail, but is merdy suggested in Figure 9. The reason for this is that a mount suited for one 1l10tor \.vill nOt fit anoth er. and besides this. all of the bors have their own pet ideas as to just \vh at a motor mount should be. The main thing is to get the weight of the motor in the right place. It is best

Flyintr and

SIDE

;1\ll l_;~~'b~~: TURTLE THE SCALE

--!l ¥ .. IN 'NC~£S

PltANE

SIDE" VIEW OF PL~E---'

~CO-MPLETE VIEWS OF ..... "':-THE "P-H" RACEPLANE NO.2--

..

FI.,;ure 3. Ttl'. tI.re~ view dr",vl .. .IIr of' tllePoncl1 "p.H."n ..... r ... Ivr. yo ....... e In.port. .. nt dlonen.lu._.

G/i"., Manual 103

IG (

OG

t

, /'

-rW

j ~~~

,i \6

I I

'f-

. 1

nf

.".

.,. _

. _

FU~ .~S[CTIO

IN (

I~""

)

[:hl:

I

~

~PPER

WIN

G PL

AN

"'-

::;-K

'lO.~

A.

u: ") ~ ... ,,

-.. ", v

J7

V'

SEC

TIO

N l

ll"'ll

l~C E

DG

( _.~

. _

1 __ .

r f...j

' F

AO

,h U

PPE

R

WIN

G

SPA

R

ReA

R

VIE

W

k;;L

;1:

: .. ,

IOL[

S FO

R

STR

U

RE

",R

SP

....

---1

&9

IN

c Ie

ED

GE

• ::;

:J.

"'T

..."J

l: t

. "I

' "'-

--or"

'T"T

'T"T

" :..

1/

L4 v

,.. "

II.-EI

tON

~

TOAQUETU~ .b:CC!==o~=o:b=o='=o=ol==o='~=ol==o~'-~

LOW

ER

WIN

G

LAY

OU

T ix

20G

A .

... W

_____

_ _

If'

'': ~21f

• )0

' •

lO'

• !

I <

::

. i

lULL

ste

mN

·'1

""'

>-

f ;:0:

-,:;;

:3

FRO

NT

LOW

Ell.

WIN

G

SP"R

R

EA

R

VIE

W

\:

"E"I

I SP

AR

IS

SA

IojE

THE

SCA

LE

IN

INel

lES

, --

..,~

" ..

" _C

ON

ST

RU

CT

ION

D

ETA

ILS

O

F W

ING

S AN

D

AIL

ER

ON

S 4

-

-OF

THE

'P

··'H

"RA

CE

PL

AN

E-

'V"

SE

CT

ION

T

RA

IL

[OG

{

, r'

t;.=::

:;='~'=

;:::

:::~

. D

RA

G

WIR

E /.

4.\

rITT1NG~

,(",

'1

, L

HOLE

S I~"

h

. 11

":

• NI

~G A

TT

AC

II.

f'-.....

\

I II

'f

Ira

MOl.E

Sl

• "I

~

/ ...

: _

#U

4 ,'-_

-+' __

+'_

r 'IV

TU

AN

8UO

IL£5

I

---.

;:-.

; _.

_ f-+

-r

r 1'"

_ :>

"~~,

110

->-

MA

CE

WIR

E LU

G ~~..--"'~'

24

RE

Q'O

1&

GA

.

A'$E~BLV

DE

TA

ILS

O

f IN

TE

RN

AL

DR

AG

B

RA

CIN

G

ST

RU

T E

ND

FIT

TIN

G

METHOD or ATTACHING

STABIUZER TO THE rU S EL..-GE

11[""1110(' I1ING[

' · REQ.'D I.G .... STABILIZER AND ELEVATOR ASSEMBlY

R["'R III[W

THE EL.eVATOR HORN or " G .... $TU.L

III Wr.LD[D . TO [L[II"'TOII TOIIQt:i[ TU8~

Of THE ASSEMBLY "P-H" RACEPL

T AIL GRO\JP-~

105

106

; ; RE,A.R VIEW or TtJIiU: TO ae

22 GJl.GE THE AILERON

SIO£ END

WU.O£O TO SUPPORT

e -RCQ'o. 10 G ....

TUBE

DETAIL or THE AILERON HORN 2-IOIEQ'O. 0,. IS G ... . CAReON lTL.

-COMPLETE DETAILS -RON F"OR THE "P- H"

AND

.. - I ...... ." G. '1'10_., deC .. U •• d ... 'Wh._ tlo .. aile"".. .. ...... t .. u e tl.... 'WIll __ ,,"" T...... _ .... k "".,.. Tn' " I ........... re .... t fr ..... till", .. II •••

to leave the motor mounting and cowling to the last. as the only practical way to attain perfect balance is move the motor a n inch o r so forward or backward as found n ecessa r}' "

Empennage Little difficulty will be experienced with

the tail assembly after hav ing built the fuse-1:I"e. for the same Jlrocedure is followed. This job will also re

A •• embling of Wing rarC. Coil. For CoreFul ACCencion Co Detail.

PERCE N T or C ,",ORO

"'I~ .... 7. '1' .... Ra.., .. ", ....... ;n.. A. F. Airfoil. _h • .., .. I ... "o~ In del.n here Rlo .. & _It. Ihe ..... 1 .. of .... dlnat .... JIIIpr .. _ .. ap .trlp ..... d 1 / 10- .. I,,-wood .... e o .... d I .. ,-"O .... lro""I .. ., rl" ... 4:: .. lb ....... n .... d_.

Layout t.he "V" struts on sOme flat sur-face. cut your 2"x I 7 gauge st eel tubing to the proper size. spot weld as shown in Fig-ure 2. then shape the tops of the struts and fit them to the fuselage lugs which a re al-ready in place. secure with ~" eyebolts. and weld according to the drawing.

Spreader bars of ~x20 gauge steel a re then measured. slotted in the ends. welded up. and a hole bored for bolting to the spread -er bar and brace 'Wire lug which is welded to the struts as sho'\.vn in the detail dra wings on Figure 2. The ¥S" square tubing axle guides are then cut and welded in place,

No'W for the axle. This should be a piece of 22 gauge chrome-molybdenum round steel tubing'" in diameter and at least 54" long. This sho uld be placed in the axle guides and the collars should be brazed at the points

shown in the drawing. The axle sh ould not be sawed to length until a fter you have the wheels on a nd the gear fitted to the fuselage. and then enough of the axle should be left to permit the placing of a hub cap. This can be made from a I n inside diameter wash-er and :l piece of 'Ys ·;x, 6 gauge steel tub-ing about ~ n long. with a 3/ 16" bolt put through the end.

The Wings The wings are o f conventional design with

the sam e bracing as you will find in other wil1gs. A glance at Figures 4 and 7 will reveal their simplicity. The spars are the acme of simplicity. as they are solid. But be sure and pick: a very good piece o f spruce for each spar. as they are the heart of the winES·

107

o 0> '" ~ ~ ~ • • • ' . ..

...

~~ • L ~

",

WHO"

"""-"

.!~

~ 2

0 C

A TO

SIN

G-

'" ,

f2 PI

J\.LE

'1

CONT

ROL

CA

8Lt

TO

RU

DD

ER) on

-

-CO

NTR

OL

WIR

E \W

£LO

luG

FI

TTIN

G

TO

TUS

E

"A[Q

.'O

. GA

o 14

~'HO

l('

0'

DET

AIL

or

FO

Ol

PED

AL

TO B

E M

OU

NTE

O O

N C

OC

I(-P

lT

FLO

OR

TO

su

n P

I LO

T

LOW

ER

PED

AL

fiT

TIN

G

4 R

EO

'O

12

GA. S

TE

EL

DE

TA

IL O

F' R

UD

DER

CO

NTR

OL

WIR

E PU

LLEY

Z

·A(Q

UU

,[O

MET

HOD

OF

STR

UTS

TO

I ..

OV

ERA

.lL

lEN

GH

T I

S l1

8fU

tCH

ES

DET

AIL

OF

CEN

TER

STR

UT

12 G

"

. ~ : ..

.

'I~.S[LIN[

LIN

E

COCK

PIT

EO

eU A

RE

L(AT

HEA

AND

PADD

ED

THE

SEAT

SA

CK

IS

MAD

E or

22

GA

. ALU

M.

CU

T TO

rtT

FU

SELA

GE,

W

ITI1

LIG

HT

FA""

'E

WO

RK

(ll

-iUt't

1C,-,

l. n

H

"'A

SS

EM

BL

ED

S

EC

TIO

NA

L V

IEW

'"

"OF

TH

E ~P-H· R

AC

EP

LAN

E ..

..

THE

SCA

LE

IN I

NC

HES

'"""'

....,

Oil

24le4

e

CONTROl.. ~TlC!,; "'ORQiUE TUB£ IS ~x 20 GA.

TOP VIEW OF

81CYCI..it H ... NDI..C l'IIue8£R GAIl>

1---2Ui.~· =.r.:i;:1:.1 AILERON CRANK'

DETAIL 2-REQ'D. I4G" .

END TOI>

FRONT END Or CONTROL STICK CRANK DETAIL

!-REa'o ·

AND OR'!"!" HOI..£

x 18 GAo W"'SHER

--COMPLETE A

X 20. G... . SA'" C£. FOA CR_K ~U"f"ORT Tu e£.

THE SCALE IN INCMES F'""'!' I o 3 • • •

i·X ZD G .... .,.UB£ TO THE RUDOER HORN

RUDDER BCI..I.. C ...... ·U ..

\l>/o.. _ _ CAANK TUBE BltA,CE

REAR

4..r>t20 GA.. TUBE TO

109

Detailed Working Drawing. of Metal Fitting. Simplify Con.truction

LOCA TION ANO METHOD or ATTACHING LOWER WINe SPARS

~"ftl;~~~TO ,HE fUSELAGE

"0

"·IKUr.,8,.TIo., .. "

d ........ I .. " ... h ·" d.,c .. n • .. t fit· fl"., ... ...,d"d t .... rlffh ... th" wh,,,. h. Che

for the wing fittings. be sure bore. being cardul not 10

wobble in the wood. as this causes a weakness of the spar at that place and gives a poor fitting. The leading edge is put on with glue and nails and the ribs are secured to thl': spar in this way.

In making the ribs. it is well to stress the fact here that these are ve ry important parts of the plane and should be built accordingly. Layout an outline of the rib on a piece of heavy brown paper and put it on a board that is smooth and level. This board should be at leasl' 38" long and 6" wide. Lay a cap strip on the outside of t he line all the way around the contou r of the rib and nai l in place accuratel),.

110

Inside of this place two more cap strips. pushing the middle one in pla(;c and nai ling the in side strip. This middle one is the cap strip of your rih. Now rou are read)' to place the spar openings. which are illustrated on F igu re 7, in their correct loc.ations.

After these are located and their correct size determined, make a block of that SIZ!' and put it in the spar place. Now cut the 1/ 16" plywood to the contour of the rib, place it ovu the cap strip, glue and nail with Y8"x20 nails with ·a flat head . Then p' a~ the other cap strip on t he opposite side and glue and nail it in place. After all t he ribs a re mad e. sand them up and fit to the spars.

A wing- splice in the spar i~ not necessarr if a piece of spru(;( can be obtained which is lon~ enough, but in the event that you have to splice the top wing spar in the center. make it a d iagonal splice 16" in length, wrap with rib co rd and glue.

In rigginl: the wing it is easiest to measu re out from the butt abou t three feet and make a mark on thl': spar. Then tightl':l1 and l~n the wires until it is the same distance diagon-ally from the wing butt to the mark on each spar. Give the wing a coat of good varnish before covering.

Tbe .Ailerons The ailerons are of the semi-balanced t\'PC

and are operated with a torq ue lube from the fuselage bell cranks. There are four hinges OIJ each aileron . and these a re made from 16 gauge steel ¥4" wide. Details for these hinges, as for all other parts of the aileron. are clearly shown on Figure 6. This type of hinge is the best if care is given in mnst ruction. but the)' must be assembled as the aileron is built if the)' are to be in line and operate smoothly.

The aileron ribs arc the regular ribs with two inches cut out immediately behind the wing spar. The aileron spar depth is then gotten from the inside measu rements of the cap strips. The trailing edge is made from a I" wide strip of alumi num, bent in a "V" shape and secured by small strips of brass nailed aroun d the aluminum and onto the rib cap strips. No other instructions are nttded here. as the drawings are given in minute detail.

The Conlrol Stick This is another part of the ship which can

be moved around to suit the pilot. There is not much room in which to play around. but the person who is to fly the ship should see that the stick and foot pedals are placed where they will permit the most comfort.

W.Il.De.igned Metal Fitting. Give Racer High Factor of SaFety

--- .~ --I!:UR ....... R

.. WC ... O

FRONT VIEW AS'sE~BLEO

,--.f ." -_UHQ-

~'-~.'~:ti UPPER 'sTRUT

FITTING .. GIl. " -RCQ'O

NOTE:' 3T .. UT ... uc:. Ii' W[LOlt:l) TO T .. C I..OWCR

• STRUT I'tTTlo.IC

DET AILS OF" THE f"LYING WIRE AND STRUT FITTINGS FOR THE OUTER STRUTS OF REAR: LOW£R $TRlJT SPARS UPPER FITTING & LOWER WINGS .. ~ " -III[Q'O

ORI ..... :fwo ... !!: ...

"hfa .... 10. Ahove.re ...... WIt dei.lled w .. rkJuK dr ..... · l .. _ of "'e .,..1 .... wire ... d .11'_1 11111 ...... 'or l"'e outer .lr .. t. of nle re.r ••• 1' .... Ito'lo _ .. per .... d 10"' ......... 1 • ., .. 0' I"e .. 0 ... ·.,11 n..te ...

The draftsman has illustrated the entire control system in such minute detail in figures 9 and 1 I. that further comment would be ~upe rRuous.

'J h~ tail skid ma}' be made of either steel or wood. but for th~s s i:.-...e ship wood w~1l probably be'! the best. although the drawing shows it constructed of steel. This is a mat-ter of personal choice. If you decide upon wood, use ash. and follow the Kenc ral Size and shape as sho'wn on Figure 9.

InstrulUcnts The only instmments n~ded are the oil

gauge. tachometef. aitimder and switch. Others are of course desirable. but }'ou can buy ,,·hat you want at the convenience of your purse.

Struts 'I'he center section st ruh are of 1 "'x20

gauge streaml ined steel. They may be madfO adjustable if SO desired. The front center strut is 15 Vz" long and the rear one is 15". '''hen these have been laid out and spot weld-ed the diagonal is cut to fit . They are then fitted to the fuselage and welded.

The front outer bay strut is 30 ~" 1011'.':: and the rear 30Ys", The diagonal is cut to the proper leneth befo re welding. The flv-ing and landing wires are of v." streamli~e cable. although stranded cable may be'! used if preferred. Before orde ring the streamline wire it is the best polic}' [0 set the p'ane up and bloclt. the win~s to their proper positions; then measure the lengths.

Covcring Cover the ship with a good grade of air-

plane fabric and give six coats of dope. T ape the ribs and wings carefully. for that" malres a lot of difference in the loob of the ship. U:;e pigmented dope for the last thr~ coats, :IS th e cloth will not stand sunlight otherwise.

I I I