7/23/2019 Eg 18741225

1/19

OUR INDIAN TROOPS

HIPS.

TIIE ships of our I ndian t ran

sport fl

eet some weeks

ago r esumed their season's runn

ing

; and the to

some extent , experimental stage

th r

ough which ' th o

machine

ry

of th ese sister shipa

is

passing with

varying success renders any account of th eir al

t erations and tr ials of value t o the marine

en

-

...

-.-

- . -

. .

F ig .

1 .

H M $ C U P H R

AT

C

Ski::vn

16 .

Va.cu.u.rrt

. . . . . :V .

Z 6

R..D

olu J.iqns .

. . . 3 9

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-

-

--

.-

-

--

-

- -

__

.,...,__

............. ---

.

--

--

---

-----

-

---

-- ................ .. ..-

-:

-

-

J

H M S . MALABAR .

St -rm. . . . . . . . . . .

44 .

Va.cr..u.an

. . . . . . . .

Z 7 .

Revotub..o u . . . . . . .

S 3

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f , '

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orf 1.anu.M

r r ~ fiF bcn.L.er

11

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6

I

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T

ubu

cf o.Ju .

pn,u., 6 .

11

I I t A

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firC.

bo

.e

__ _ _ _ .

z., 5

f 1 t

t .

Waur bpaa.

1

bcJv..n,d

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bOx _

1

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0

0

o I

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I I

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I

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II o

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;

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f

I t

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0

0 0

0

0

0

0

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I

'

'

/

E N G I N EE RIN G.

of over

24,000

miles per season, but that four only,

the Euphrates, Malabar , Ju mna, and Crocodile, are

in use during the pres

ent

sea.qon-we proceed to

deal with t hem in detail, beginning wi th the firs t t o

leave home.

?-,he E uphrates retains the original engines and

boilers. Tb. e en gines are horizont al, non-com

pound, with t wo 91 n. cylinders 4 ft. 6 in. stroke,

'

'

'

F i

G

'

,

7/23/2019 Eg 18741225

2/19

E N G I N E E R I N G.

TABLE I

. -TRIALS

OP TBE hmu. .N

Tn

ooPSntPs AT AN

APPROXIMATE

SPEED

OF

10 K NoTs .

Name of sh ip ..

Euphrates.

Malabar

I Jumna..

Croc

odile.

Uld or new screw

Old

;:

-

------------

Y

. pu

blished

an account of the

.rumna's

trials

durmg th e summer;

and

in

view of our account

t

hen* of her

mac tinery and it

s

work

it

is

scarcely

necessary

for us to

say

much D O \ \ ~ ..

'

may

repeat,

~ o w e v e r

t l ~ a t

th e c s s ~ ~ a s o r ~ . g r n a l l y fitted with

s1mple engtnes, th ree t7-In.

cyhnders,

horizontal

return

00nnect

ing rod s, and

surface

condensers that

Old New I New Old j

Griffitba

l l

irsch Griffitbs

New

Kind of propeller

Griffi.tbs

{

Griffi

ths }

modified

New

Hirsch

Nmnber of blades

2

P1tch

...

. .

27 ft. 6 in.

2 4 I 4

27 ft. 6 in. 27 ft. in. t32ft. 6 in

4

27 ft. 6 in.

Griffiths

2

27ft.

4 ~ h e s , , e

were. compo.unded by

reducing n-od "t;unk

-

1.7 ft. 7i in

th

ddl 1

1 ~ g em1

ecy.mde

r , andsorenderingitseffective

Din meter

...

. .

21 ft.

'Length

.

.

4

ft.

I

0

;}

in.

I

mmersino

91 in.

21 ft. 2 io.

4ft.

4

in.

in

2L ft. 20ft. 11 io. in

5

ft.

2i

io. 2ft.

4i

in. 4ft.

5i

iu.

20ft. 1t in.

4

ft

in

.

:W ft.ll ~ i n . d t ~ m e t e r t o 57.96

10 . ;

and

that each cylinder is fitted

2 ft.

3

1n.

wtth

a

cu t

-off

va

lv

e.

The

old

boilers were

at

the

...

.

Sc

rew ab

ove

water

...

...

31\

in

10.98

.

.

- io.

in. same

time

replaced

by eight

circular boilers of

which

we give in Fig. G an outline end view.

1

T hey are

pressed to 70 lb.,

and

fitted with steam domes and

Sept.,

1874

Se

pt., 1872

Se

pt., 1 8 / ~ Oct., 1872 Jan., 1873 are

n?t

given to priming; but their power dcveioped

at

in.

1 ft.

in .

21.61

lip per cent ..

...

When trit.>d ... . .

Number of days out of

..

2.'17

5.2

October, 1872 October, 187 3 Oct., 1872

...

...

...

. .

7.98

8.Ul

13.

61

6.56

dotk ... ..

:

\It.>nn

draught .. .

11 2

19

ft. 6 in.

19 ft.

9 in.

)

H 2

48

19f

t.3i l.

9 f t . l l i o . l 8 f r . 7io.

4 ft. 10 10. 4ft. 9 io. 5 ft. 1 in. 3ft. 10 in.

1

19 ft.

3

in.

ft. 6 in.

lb.

on tnal, namely, 2903 horse power, was much less

2 than that (4894

horse

power) of the

boilers

they

19 f&. in. replaced.

Ship by the 6tern ..

Load on fafety valve ...

Prt>ssure on boilers ...

Mean pressure in

6 ft. 6 in. 6 ft.

lb. lb.

17.5

17. :)

Jh.

lb. lh. lb.

5

f

t.

8

in. The safety a l v e s are ordinary conicn.l valves,

t ~ o to

each

b o ~ e r , but

lo

aded as

shown in Fig 7

18.3 16.5

1: 1 1\:3.1 I 15.0 17.5

16.6 49.3 I 14.4 15.9

17

: )

18.6

17.5 E ~ c h has two sp1ral

springs, one

inside the other

c01led in opposite directions, both of round s e c t i o

cyI

nde

rs .. ..

Vacu um

...

..

.

11

.3

25 5

in.

11.5

26.4

io.

11.2 12.02:

5.82

1

2.

7 12.R

28

in.

26

io. 25io.

22.8

io

10

5

2

6.5

in.

11

il -one T

9

11

,

and the other

in diameter. Th ey

2

8.0 in. have. given satisfaction during

the

pas t season.

Rev

ol

uti

ons

per mi-

nute

. .

...

Indicated ho

rse power

~ p e e in knots ...

ApproximateindicatPd

horse p

owe

r

at

10

ku ots ...

...

40 .4:

173

10.742

1

399

41. 2

1797

10.600

1

509

4.1 .2

1625

10.436

HoO

36 7

1

08.)

9.213

1

387

35.l

1507

10.3:)1

Vl58

4 )

, t

2054

10.255

1905

46.G

1582

10.726

1282

4

l.

9

1531

10.681

1256

Calc

ul

ated on the aassumption that the indicated horse p

owe

r va1ie3

as

the

cube

of the

speed

.

. l'ABL"B H

The

Indian

Tr

oopships

Apprnxtm ate distance in knots steamed per ton of coal

at

1\0 average of 10.knots an hour : calculated

fr

om t.heir per

forman ces at an average speed ofabout 9 knots an hour.

.

.,

Q,)

Q,)

::=

work is all very well

, but considering

that

the real

work of

the eng ineer is

to

design machinery

and

n

ot

to

make it,

it ce

rt

ai

nly

see ms

the

r

everse

of prac-

tical to

teach

him the la

tt e

r

without, or

at the

ex

pense of, the former. vVe, therefor e, hope

that

as

ti m

e

go

es on it

may

be

found practicable to modify

t he

cur

riculum at the

Crystal Palace

in

the

direc

tion we ha.'e indicated. \ Ve

feel

sure that this

would comluce to

th e re

al

in ter

est

of the school as

well

as

help

f o r ~ v a r d

the cause of

sc

ieo tine edu ca

tion,

while

it would

ce

rtainly

make t he

work

of

the

P rincipal

at

once

more

agreeable

in

i

tself

and

more

satisfactory

in

its

re

s

ul

ts.

As

a

step

in the

rig

ht

dire

ct iou, ho

wever, although

p e

rhaps

a

timid

oue,

we

are

gla

d that the

Cr y

stal Palace School is

pro

s

pering, and

co

rdially wish it

success

in

the f

utu

re.

POWE

R

FOR

DRIVING

TOOLS.

O o n c Z ~ u l e d f r o m page 40

1.)

IN

the

case of

those

to ols whi ch

ope

ra te

by

re

moving shaving

s

from

th e m

at e

rials

un

der

treatment,

t he

weight

of

the

sh

av

ings

produced,

or th e cubic

cont

ents

of

the materials reduced to shavings,

afford

units of

comparis

on for

ascertaining pow er

required

to

do

the work

as

di

st

inguis

hed fr

om

that

necessary to run the machines when em

pty.

vVh

at

ever

m

ay

be the ma te

rial under treatm

e

nt

the size

or section of the sh avin

gs

removed is

found

to

in

fluence

the power

r

equired to do

a

certain amount

of

work,

but

both the extent and nature

of

th i

s

influence are f

ound to

vary

in

diff

erent

materials.

This p ortion of the subj

ect

was partially

invest

igated

by

Dr. Hartig, and

altho

ugh

th e rese

arch

es in

th i

s

direction were

n ot e

xbausti

ve,

it

may be

stated

that

as

a general r

es

ult materials of a

brittle

or crumbling

natur

e, s

uch

as

cast

iron, can

be r

ed

uced mo3t

economi

cally by heavy

c

ut

s, while w

it

h materials

which give tough curling

shavi

ngs the

o

pp

osite

app

ears to

b e t

he

case . \

Ye may

r

ema

rk here

that

this subject has

also

re

ce

ntly

been

in-vest

i

gate

d b y

M. Tr esca,

an

d

we hope on

some' fu

ture

occasion

to

be

able to compare

his

conclusions

with th o

se

arr ived

at by Dr. l:i

artig.

F orty-eight

trial

s

were

c

arried

out by D r.

l lartig

to d

eter

min e

th

e

power required

to plane per

hour

from cast ir

on a kilo

gramme of shavings of

various

sections.

Redu

cing the re

sult

s 0btained t o

Engli

sh

wei etht s

and

meas

ur

es,

and exp

r

essing the

mean sec

tion

0

al

ar

ea s of

the

shavings

r e

moved in squa

re inches,

we have t he followin g fo

rmul

a expressing the

po

wer (P)

require.d

to rem?ve

a given we

ight

('

)

in pounds of cast

1ron sh

avmgs

p er hour:

P=

w.

( o.0155 +

1

) . .

(26)

H

,VOu s

In the ca

se

of

st

eel,

wrought

iro

n,

and

g

un metal

,

ENGINE E R IN G.

th

e re

lation

between

the

p ower

required and the

sectional area

of

the

s

havings

r e

moved could no

t

be

s

atisfactor

ily

ascertained; bu

t

the

gen

eral

resul

ts

when

planing

with

cut

s of

an average

character

were found

to b e

as

follows :

For plan

iog steel P

= 0.112

W .

2

1)

, ,,n-

ought iron

P

= 0.052

W . (28)

, gu n-metal

P

= 0.0127

W .

(29)

A

r

emarkab l

e

result

s

hown

by

Dr. II

a

rt ig's

ex

periments

was

that

for pl

aning the values of P

were

fa

r

higher than when

similar

shavings were

removed

in

a lathe.

Th u

s

in

tu r

ning the

average

r

esults

were as foll

o'

'S,

\

presenting,

as before,

th

e

number

of po

und

s

of shavings removed

per

hour:

Ftrtu rnin

gto

nes.

run at High Speeds.

run ut

Slow Speeds.

-

Oast iron ...

8te

el

...

Wrought

ir

on

..

.

...

ValLles of

K.

0 . ~ 2

1.29

0.4 L

, I

Values of

K.

0.72

0.9 t.

1.00

Thus i f v equal th

e

surf a

ce ve

locity

of

th

e

stone

in

fe

et per

minut

e,

an

d p

equal th

e pr e

ssure in

po

unds

exerted

upon the ma terial to be

gro

un d

, th en the

pow

er

required

to overcome th e

resistance due

to

this pressure will of

cour

se

be

P=P

K .

v

3a,uvv

(47)

T o

obtain

th e total

power requir

ed to

drive

the stone, th e po wer calc

ul

ated by th e

formula

(47) will h

ave to

be added to

that

r

eq

ujred

to

driv

e

the

stones

e

mpty

,

f\S given by

formulre

(9),

(10), (11),

or

(12)

on page

431

ante.

l n conc

ludin

g

our

su

mmar

y of

Dr.

H

ar t

i

g's

r e

sea

rches we

may

give

the

r

esults

of so

me ex

pe

ri

men

ts ma

de by

him on

spe

cial ma

chines, which

cou

ld sca

r ce

ly

be

includ

ed in

any

of the classes

previ

ous

ly dealt with.

F or

inst

ance,

in the

ca

se

of

a screw

-cutting machin

e

on

Seller

s's syste

m,

it wa

s

found that

the

pow

er re

quired to

cut

scre

ws of

diffe

r

ent diamet

e

rs or

wrought-iron bolts,

might

be

ex

pr

essed by the following f

ormula:

P=5.

l.d

3

64

(48)

in whi

ch

l= t

he

length

of

screw in ft

et cut per

hour and d =diam

ete

r of bolt

iu

inches. " rhen the

7/23/2019 Eg 18741225

13/19

49

6 ENGINEE RING. L0EC.'l5, 18

14

~ ~ ~

~

~ = =

= = = = ~ ~ ~

~ = =

machine is

becomes:

employed in tapping nuts

the

f

ormu

la

P=

1d 3

28.78

Hl

Both thC'se formulro ( 1S) and (49) give th.e

p w ~ r

nqnir

7/23/2019 Eg 18741225

14/19

'

ENGINE FOR DRIVING

FORGE TRAIN,

AT THE

KING

OF

BURMA.H'S

IRON WORKS, NEAR MANDALAY,

Bl

JRMAH.

,

-

0

NOTES FROM SOUTH YORKSHIRE.

SHEPPIBLD, Wednesday.

Contemplated

Br eah'P of

tile Nine H

01.trs

S Jstem.-At

several

of

the chief steel and iron works

in

the Sheffield dis

trict notices have been given to the

men

that they will , with

the beginning of

he

new

year, be required to work 69 hours

per

week instead

of

54 as

at

present. The labourers are

mainly affected by these notices up to now, but it is supposed

that s1milar acti on will

shortly

be taken

in

those departments

where skilled workmen are e n ~ a g e d At the Atlae, Cyclops,

Sheffield, Phcenix, o n f i e Carlisle, Brightsi de, and

other

CONSTRUCTED BY MESSRS. CLARIDGE AND CO., LIMITED,

(FO I Descript-ion, P age 489.)

ENGINEERS, BILSTON.'

'

0

L-

r

~

0

-

/

c:@: D)(

0

1 l

l o

lcJQXI

oj

-

iron and steel works wag

es

are being reduced by from

10

to

26 per cent., and large numbers of

men

are being discharged.

In

two instances the workmen are on strike against the re

ductions and are being supported by their

trade

union.

Plux:nix B essemer Steel Company L imited).-

The share

holders of this company have received circulars intimating

that the directors deem it desirable

that

the dividend recently

declared should not be paid at

pr

esent. owing to a heav,loss

which

has

been incurred o

wing

to the breaking down o part

of the machinery

in

the works .

S1mdry Engin

ee

ring Movcmcnts.

- T wo new shafts have

0

L..

'-----

110 @ 0

T

r

,

"----

-----

J

0

i

llS:J

been commenced at the Wharncliffe Woodmoor Colliery, near

:Barnsley, and

the

Silkatone, or lower, seam is be

ing

sunk to

at H oyland Nether. The new shaft of the Yorkshire and

Derbyshire Coal and Iron Company at Carlton is

making

good progrees. A large coalfield

at

South Xirby is on

the

p

oint

of being opened

up

, the price

to

be

paid

for

the

:Barnsley coal being 35l. per foot per acre, and

261.

per foot

per acre for the minor seams.

Th

e Midland RailwaY. Com

pany

are about to lay

an

additio.nal double line of rails

part

of the distance b

et

ween Sheffield and Masborough. The

Maneh

es

ter, Sheffield, and Linco

ln

shire Railway Campany

are on

the

eve of laying down a pair

of

through goods lines

0

0

--

,.-I -

D

_ _ _ _ _ ;

0 0

at Sheffield, so as to i a t e the necess

ity

of carrying on shunt

ing

on the

main

lines.

Th e Pr ice of Steam Coa l.- The pri ce of Eouth Yorkehire

steam coal has been reduced l s. per ton, owing to the very

general depression of trade.

N ew Water

1Vorh

at Doncaster.-Tbe

fir

st

stone of a

new

reservoir for the

water supply

ofDoncaster was laid last week.

Its capacity will be 270,000,000 gallons, and area of water

surface 56 acres. Its site is in the Silverwood Valley, near

Thryburgh. There will be two other

sn::

nU

er reservoirs in an

adjacent valley of a joint caJacity

of

about

22,

000 gallone.

~

trJ

)

t.>

Lrt

-

00

-l

t

J

t Ij

z

Q

z

t =j

t =j

~

.

z

Q

\0

4

,

7/23/2019 Eg 18741225

15/19

7/23/2019 Eg 18741225

16/19

7/23/2019 Eg 18741225

17/19

soo

give an increased

range

of a t.

6

in. ; the ebb

current is

conaeq.uently inoroaae

d.

All thie, aided bY, a eyeteme:tic

dredgmg

of

shoale,

h s produced

a correspond1ng progross1ve

improvement of the Port of

L o

ndon,

and

the still greate

r

extension

of

these benefits is only restrained by the com

J

la

rativo

emall funde a t the disp

os

al of the Conservancy

Doard.

As

regarda the

general

increase

of r a n ~ e an examination

of the la

st iseue

of the

Admiralty

chart

g1ves

even

a higher

reault ta-n estimated in

my letter

of 6th October

last,

Tiz.,

a

fall

of

hlgh water from London

to

Sheerness

of

3

ft

. 9 in. in

lieu

of a ft.

6l in.

for springs,

and a

fall of a

t. 1 in.

in

li

eu

of 3ft. for the fall of

high-water neaps- tho same

fall

for-half tide range,

viz.,

14 in. ; but the

l

owwatr

r

neap

dif

ference

is 18

in.

rower

in

L ondon

instead of

the

same as

at

Sheerness,

and

lo

w-water springs 11 in.

l

ower in London in

lieu of 13 in., and the

mean

low-wat

er difference

in

fav

our of

London 14 in

.

in lieu of

1

3. in .- th

ese differences

ari sing

from

a variation in the

mode of

estimating

the

neap ranges.

I t

ia, howe

ver,

difficult to tie

in the Gravesend rang

es,

given aa 17 ft.

6

in. for springs and 10 ft

. 6 in.

for

n

eaps, or

14f t. averare ra nge, whereas a series

of

nearly three years'

obse

rvations

(181.2-45) show

that the

range

of

tide

th

ere

thirty

}'ears

back averaged

l G ft.

for the

en tire

year.

.An

analysl8 of these tides

(1848-44) shows

that

during

th

ose

years

tho mean spring range

was 19

ft. 2 in. and that of

ncaps 12 ft . 6 in. , and

the

mean ha.lf-tide range

was

11

ft.

8 in.

below

Trinity

as c

ompa

r

ed with 10 ft. in

London

and

11

ft. 2

in. at

Sheerness.

At that time low

water

of springs

would therefore

be l

ower

at Gravesend than L ondon by 6 in.

and

Sheerness

by 20 in., wherea

s

the

ranges

giv

en in the la st

chart would

make

Gravesend low

water

of springs

4

in

.

above London and

that

of neaps

1

ft.

5

in

.

above and

th

e

mean

low

water

would be

10 in.

a b o v ~

L ondon

low

wa ter ,

and respectively

10 in., 1

in.,

and 6

1n. lower than

the low

water springs, low-water

n eaps,

and

me

an

low

water at

Sheernesa.

I

am, Sir, yours truly,

J . B.

RBD.MA.N,

Me

mb.

I

.C.E.

11,

Gr

eat Queen

street,

Westminster,

S.W.,

December,

1874.

NOTES FROM CLEVELAND AND

THE

NORTHERN COUNTIES.

MIDDLBBBROUGH, Wednesday.

Th6 Cleveland Iron Market Yesterday there

was

a

thin attendance

on 'Change,

at Middlesbrough,

and

vory

littl

e business

was

done.

The

market was decide

dly

flatt

er.

At

this season

of the

year there is generally a weakness

in

pr ices,

but

yest

erday the down

ward

tendency was marked. There was

a considerable

diff

erence

in

the

qu

otations. A merchant

de

-

r

olared

to our

re

presentative that he

would sell

pig and

finished

"iron. at th

e following pr i

ces: No

. 3 Cleveland

pi

g 61s.

per

ton,

No. 4 forge 66s.,

white

63s.

delivery this

m

onth

. Rails

n.

per

ton, angles Sl. l Oa., plates 9l., and crown

bars

Sl.

1 0 ~ .

per ton less 2} per

cent.

For de

livery in

January No. 3

Cleveland pig can be bought

at

60s. per too. Within the

last few

days puddled bars have

been off.,red

as

low

as

6t

2s. 6d. p

er

ton.

Tlte Finished Iron

Trade.-In

illustration of the condition

of the

finished iron

trade,

we may state

that

at

th

e Cleveland

ir

on mark

et yesterday

10,000

tons of Welsh rails

were

offered

as low as 6t

per ton f.o.b

at

a

Welsh

port, aod

did

not

find a

buy

e

r. t s said that

these-

rails

cost more t

han they

are

now

offered for. Although

th

ere is a

speciality

about

those rail

s, yet the

fact

that they are in the market at such a

low figure

s h o w ~ that th ere

is n

either

.a d ~ m a n d for nor

sp

eculation

in

ra1ls. M

ost of the large

rail

mlll

s are off

for

want of orders

,

and

a great number

of

men are

out of

employ

ment. At Darlington,

Stockton,

Mi

ddlesbro

ugh

,

and

B1shop

Auckland,

there is such an amount of distress amo

ngst

iron

workers

and othera,

that

r elief committees are

kept fully

occupied

in

obtaining

assistan

ce to prevent many families

going into the workhouse.

The Coal

md

Coke T,-ades.-

In

the coal and coke

trades

there ia

little alteration.

Ma n

ufact

uring coal can be bought

a t

Ss.

per ton, and it

is

expected that

prices will be lower.

Engineering

and

Shipbuilding.-On the nort hern

rivers

there is

still

a good

deal of work on hand at

the various

ship

yards. On th

e Tees

the

builders

are

so

busy

that

they have

sufficient orders

to

occupy

th

em fully

for

several months.

Tlte

Future

of t te

Iron Prade.

-M any inquiries are made

of

experienced

ironmaste

rs and. merchants.

as

to

the

future

the iron

trade,

and more e s p c o u ~ . l l y as to

1ts

probable

condl

tion during

the

year 1876.

S e v e r ~ l

.

of th

e l e a d i ~ g com

me rcia l men

of th

e North, whose optruon

generally

1s ,worth

having,

say

that

on

this question

they have .

no

opinion,

and

that it is

impossible to predi

ct with any feehng

of

assurance

that trade

will

materially

improve

during the

n

ext tw

e

lv

e

m

ontha.

There are others, however , who a re

more

hopeful.

They

beHove

that the present dep

ression

w i l ~

~ s ~

Jike

y

continue till about

February

or Mar

ch ,

when

mqumes

w11l

begin to be made

for

finished iron,

an

d

that by May next

a

)llrge number

of

rail orders will

have

been plac

ed

in theNorth

of England

,

and that

co

nsequently

trade

generally

will

be in

a

fairly

healthy

state

.

I t is earne st ly

h o

ped that these pre

dicti

o

ns may be

realised.

L oNDON

Asso

c

uTION o ~ r Fo

n

EMBN

ENGINEBRB AND

DnA.UGRTBMBli.-The

twenty

-

third annual meeting

will be

he

ld

at

the

City Terminus

Ho t

el on Sat

urd

ay,

a n u a r y

2, ~ 8 7 5 ;

On

this

occasi

on the balan

ce-sheet,

togeth

er wt

th

the

aud1to

rs

report thereon, will

be presented,

a

President, Vice-Pre

s

ident,

and other officers

will be

elected, and

the ~ o i n g

P resi

dent (Mr. J. Newton) will d e l i v ~ r

a':l

a ~ d r e ~ s . ' he n t y -

third anniversary fcst1val

of

the lOStltutl?n 1a

now

de.6.mtlvely

fixed

for Saturday

the 13th

Ma r

ch, m stead

of th

e

20th

February as previ

oualy announced.

Mr. John

Hi

ck

s, M.P.,

has conse

nt

ed

to preside

on th is

latter

occasion .

E NGI NE E R I NG.

D A V I S S

l \1 INING

DIAL.

Wg p

ubli

sh an illu

st

ration of an in

st ru

ment la t

ely perfected by

M

essrs

. Davis

and Son,

of De

rb

y , and possessing

many

advantages

over the

ordinary

Il

edley

dial.

In

this

latter the vernier

cannot

be

used

in

conjuncLion with

th

e

ne

edle,

wi t

h

out

first cl

amping

the

body of the

dial,

wh i

ch

involve

s a loss

of

time,

while

th

e r

epeate

d

operati

ons

of clamp ing and uo claropiog

i

nduce

wear, and throw

th

e instrument out

of adju

s

tment.

The

impr

ove

ment in 1\Iessrs. Davis's dia l

consists

in

the addition of

a plate under

the

body

of t he ins tru m

ent,

which

projects

be

yond the body,

and the circ

umference of

whi ch is

divided in t

o

360

deg.

This

plate

is

clamped

to

theball

-and-

socket

j o

int, and

re

main

s rigid. r

rh

c

swing

s ig

hts mov

on

axes

fixed

to the body, on the outside rin

g

of whi

ch is

attached

a v e

rni er

,

which

r

eaus

upon

the plate A to th ree

minutes.

By this

arrangement,

on taking a sight

the angle

can either be read

fr om

tbe ve

r

nier or the

needle.

Tbe figuring of the

nee

dle ring is

reyersed,

th

at is the east and west points

change places, so

that

the angles are r e ld

off

correctly,

and the figures on the vernier

ri ng are so arranged that the reading of the

needle

and the verni

er

ring

coincide.

An

effective mutual check is thus established,

and any error arising from incorrec t

read

ing,

or

from any

local

attraction is readily

d

etected

. Accurate surveying with this

inst

rum

ent

can

thus be

reli

ed

u pon, so far

as the magnetic bearings are concerned.

The ar

c sho wn at C works as in

th

e

ordinary Hedley dial,

being fixed

a t the side

of

the instrument, so that it eau be

eas

ily

read a t

any

time, and is not

in

the way.

One

great advantage possessed

by

this

ar

rangement is, that

if

the instrument

be

out of

adjustment, the error is at

once detected by

comparing th

e needle and

th

e vern ier

readings.

:NOTES FROM

THE

NORTH.

GLASGOW, Tu esday.

Glasgow Pi g-

Iron

Ma1'ket.-During the last

fe w

days

th

ere has been no new feature of any importance in con

nexion with the pig-iron trade except the reducti

on

in price

fr

om

843. 6d.,

wh i

ch was the closing quotation

a . ~ t Wednesday,

to

82s. 3d. sellers,.

and

82s. bu yers,

yesterday afternoon,

and

8ls. 3d. to

81s. th1a forenoon.

Makers

we

re unwilling to

re

duce

quotations on Friday and

yesterday

, but to-do.y

they showed a more willing disposition

to go

w1 th

the tid

e so

far as

the

price of

warrants was conce

rn

ed. A good business

was

done to-day a t the

reduced

rates. During the

latter

part of la

st

week the stook of pig

ir

on in Messrs. Connal and

Co.'s public warrant stores was inc reased at the rate of from

400

to 600 tons per

day, and on Saturday it amounted

to

31,619 tons.

Th r

ee

of the

bran

ds of

No. 1

ir

o

n-Coltness,

Langloan, and Calder- w hich were quo

t

ed at

100s.la.st week,

are now down at

05s .,

wh ich

is also

the

q,uotation

fo

r

Gart

sherr ie, Summ er ee, and

Shotts,

otherw1se

th

ere is no

ma.

terial change

to

note

in ma kerd'

quotations. Last week's

shipments

amoun

ted

to

7824 tons as against

9166

tons

in

the

co

rr

esp

onding

week

of last

y

ear.

The MaUeable

I r o 1 ~ Trade.- Th is branch

of the

iron

trade

is

in

an

exceedingly dull and

un

satisf

act

or

y

st

ate. Sl\les a

re

being made only at rare intervals

and for

small quantiti

es,

while th

e hop

eful

fee

ling that trade

would

impr

o

ve towards

the end

of the

year has entirely

died

away. The dul'ness has

n ow become

ch

ronic. Severe comp etition

for order

s causes

a co

ntinu

ous

s l i p p

aw

l y

in

price

s,

which

are

already

n

ow

below a remu ne

ra t

1ve p

om t

.

The Dispute

in the Shipbuilding Trade.

The

strike among

a

porti

on

of the

s

hip carpenters and joiners on the Clyde

ha

s

now quite terminated. After

learning-

that

th e

em

ployers

were

willing

to modify the reduct10n

from

ld. per

h our, as orig

inally ann

oun ced, to

d.

per hour, the men took

a

day or

two to think over the matter,

and

finally resolved

by

a

large majority to

acce

pt of the

modified

terms.

They

are all

n ow

again at

work,

at

lea.at so

many of

them

as the

employers had

r

oom

for.

Mine1's' D elegate Meewng.- At a m eeting- of miners' dele

gates,

h

eld

,in Glasgow

to-day

,

from the

pr1ncipal

organised

districts of

Scotland, Mr.

MoDonald, M. P

.,

announced that

he had

rece

ntly had an in t

e

rview

with

th

e Ho

me

Secr

etary,

by

request of that

gentlemtLn,

an

d that, amo

ng

other things,

the question

oflegislating regarding gunpowder in and ab

ou

t

collieries

was

seriously discuss

ed

. Th e

right

hono

ur

able

gentleman is

opposed

to miners having

to

carry home and

store

their

suppli

es

of gunp

owde r in their own houses, an d

he

is disposed

to make it

compulsory on

the part of min

e

ow

ners

to provide

suitable

magazines

in

conne.x.ion

wiLh

all

collieries

wh

ere that explosive material has

to

be used

in ordi

nary

working.

TAe

Hi g

ltland Socieftg's Forthcoming Show in Glcugow.

-

At

a meeti

ng

held

in

Glallgow

last

w

eek

r

ega

r

ding the

great agricultural show wh ich is to Lake place in this city

next summer,

Mr. Flet

che

r N. M enzies, the Secretary of the

Highland

Society, mentioned with regard to

th

e implement

A

c

0

department, that it

was proposed to

give

special

premium

which would

be awarded on the

report

of the Impl

eme

nt

Com

mitt

ee-fo

r machines for thinning turnips, and machines for

sp

r

eading manur

es.

That

idea

had been adopted in cons

e

quence of the

scarcity

and

high price of

labour in the

agri

cul

tural districts.

Th

e Dwnifries Peat

Fu

el o n ~ p a ~

(L i

1ni.ted).

In

th

eir

first

annual

report

the

di rec

tors of this

company

state that

they

ha.ve

lab

o

ured

under

peculiar

difficulties

- p ropr

i

etors of

mosses withdrawing pr oposals after several months' negotia

tions, confli

cting stateme

n

ts

as

to

the

merits of various

p

eat

machines,

and th

e o

rg anisatio

n

of another

peat

company in

Dumfries.

They

had acquired

a moss, however, 450 acres, on

a 21 years' lease, in th o parish of Ro

thwell,

and commenced

cutt

ing

in

May.

Those

cut

in

J

une

were r

eady

for fire

in

21

days; and altogether 371 tons were cut and dri

ed

at a cost

of

63l. 16s. lOd.,

or

7s. p

er

ton,

being 73l. la

.

2d. profit

on

the

cost

of labour. All these

p

eats were cut with the spade and

dr ied in

t h ~

open

air;

as it was deemed inexpedient to pur

chase machinery

in the m ean

time.

The

company are unable

to

de

liver peat in Dumfrie

s

under

16s. a

cart

.

NOTES FROM THE SOUTH-WEST.

Wa t

er Suppl;y of

JJ'rome.

A

sch

eme

f

or improving the

wa ter

supply of From

e

has

been

abandoned for the present.

T

he pr

oj

ect

would

have inv

o

lv

ed

an outlay of at

least

20,000l.

S t a t i O t ~ ccommwdaUon at Ca1 dijf.- vVe understand that

the

Great Western Railway Company have determ ined to

pro

ceed with

th

e erection of a new station at Cardiifin March,

whether

an ar rangement is

arrived

at with

the

Tafl'

Vale

Rail

way

Company or not

upon

the subject.

Blaina I1onwo1kers.-.A novel strike is re ported from

Blaina,

the

strange fea ture co

nsisting in

Lhe motive, wh ich

is alleg

ed to

be due to

the

non- s

upply of top

-coa

ts

to

ce

r

tai

n

wo

rkmen. Six of those

con ce

rn ed in the st

o

ppage hav

e,

in

consequence,

been oharg

ed

at the Tredegar

police co

urt

with

absenting

themselves

without having given proper notice.

The prosecutors did not presa

th

e charg-e, and

the defendants

were fined

only la. and

costs,

in

addit10n to

being ordered

to

pay ll. towards cover ing

th

e damages which had resul ted

fr

om

their conduct.

New Works on tlte

Gr

eat W estern.- The est imated ex

penditure for new works

on

t.he

Grel\t

Western R ail

way

for

the half.year ending January 31

,1875,

is 323,012t. This

ex

pe

nditure has

hPen

made up

on new

stat

io

ns, new sidings and

inc

rea

sed

accommod

ation,

locking

junctions,

poin

ts and

signals,

mixed

gauge arrang

ements,

new engine sheds, &c.

-welsh Jlai/;w I J Traffic.- ln tbe

coureo

of

th o

half-yea

r

now closi

ng,

th

e

.M

o

nmoutbshire

liail

way

Com

pany has

.ac

quired 88,263l.

against

90,360t.; the

Hhymney

53,8U ll . agam

st

60,725l.; the Cambriao

95,8 10t.

again

st 90,0ts4l.; and

th

o

T d

f

Vale

207,720Z. against

187,429t

.

m t Tra1nwags

.-Colnn

el llutchins

on

has made an

inspect1on of the Newpo

rt

tramways. t is expected

that

his

repo

rt

will bo received

in

a few

days, and that

then card

will

be run

every ten m inutes.

7/23/2019 Eg 18741225

18/19

ENGINEERING.

C O C K B U R N S

E Q U I J . . , I B R I U M

SA

CONSTRUCTED

BY

MESSRS.

D. COCKBURN AND SON, ENGJ

? 1

c

c

r

. Z

l i the concluding po

rt i

on of

the

report on Safety

Valves., recently made to the Inst itution of

Engineers

aud

Shipbuilders in Scotland, and published by us on page

'68 of our

number

of

the

11th instant, reference is made

to

an

arrangement of

va

lve

bl

owing into the aea

without any

in

crease

of

pressure. This arrangement is

illustrated by Figs. 6, 8, and 9 given on the page ju

st

re

ferred to, these sketches being reproduced from tbe com

mittee's report, but the report

itself

cont

ains

no detailed

description of

the valve

used,

while

the views

given are

drawn to too small a scale

to explain

some points in

its

construction properly.

Un d

er these circumstances, com

bined

with the fact that the valve has been a very suc

cessful one, we have thought

it advisable

to illu

st ra t

e

and describe it

more

fully.

The valve in question is one

patented

and

made

by Messrs.

D.

Cockburn and

Son, of

Crawford

-street,

Port

Eglinton,

Glasgow, and the annexed Figs.

1, 2,

a and

4

show three

nrieties

of

it.

A description of

Fig

s.

1

and

2,

which refer to

the

valve fitted

up with

the

silent

di

scha

r

ge already

mentioned,

will serve to explain

the wh

ole. This

va

lve, which is 1t

in.

in diameter, was applied to the boiler of the steam

yacht

Griffin, this boiler being worked

at

60 lb. pressure, and

having three furnaces containing

60

square feet of fire

grate area.. The steam

escaping

through the valve waa not

discharged freely into the atmosphere,

but

was led down

through a pipe and di:fcharged through

the

vessel's side

below the wa ter line. The arrangement and details of this

discharge pipe

are shown

by

F i g : ~

6 and 9 on page 463 of

our

number

of the 11th

instant,

already referred to. Not

withstanding this arran

gement

of the discharge,

and

the

large fire-grate area, this valve

was

found capable

of

pre

venting any accumulation of steam pressure beyond tbat to

which it was loaded.

Th

e manner in which this r

ed

ult is

obtained is as follows: Referring to

Fig. 1

it will be seen

that the safety valve proper,

BB

, is an

ordinary valve

with

feather guides and bea

ri

ng

upon

a narrow

fiat

seat. Below

the tiange c mying th e seat of the valve is formed a

chamber C

and

the feathers of the valve are prolonged

downwards so to

carry

a disc A A, which nearly fits

an

opening fo

rm

ed in

the

bottom of the ch amber C. Tbe resul t

of

th i

s arrangement is, that on ita way to escape through the

valve when the la t

te

r is li fted,

the

steam has to pass through

the narrow

annular

apace

0 0 ,

and

in

doing eo it becomes

wire-drawn, causing

the

r e s ~ u r e in the chamber C to be less

than

the boiler preisure. The upper aide of the disc A is

thus, as soon as the valve opens, exposed to a less preasur e

than the lower side, and thus the valve as it lifts is assisted

in opening by the excess of

pres

sure on the under aide of

the disc A.

The disc

A

h u

a thickness equal to the li ft of the valve,

and its periphery is

turn

ed to such a form as to

in

crease

the

annular area

0 0 as

the

valve rises, the ratio

of

this increase

varying

according to the

way

the valve is loaded. I n the

case of the va lve fitted to tbe Griffin, the bottom disc was

originally mad

e as

shown

at

D,

Fig.

2;

but

this

form,

although suitable for a spring-loaded valve discharging into

the a tmosphere, was f

ound

not to

give

sufficient lifting

power to overcome

the

resi

stance

of tbe water in

the

case of

the discharge below the water line. In this latter case it was

f

ound

that,

wh

en the valve commenced to rise, a good deal

of

power was requ

ired to

set

in motion

the wat

er in

tbe

pipe,

and he n

ce a disc

was

applied hav

ing

the

edge

fo

rm

ed

as shown

at

E E,

Fig.

1. This form was fou

nd

tJ an swer

perfectly, as we have already stated. Wl.lile spe

aking

of

tbis

silent

di

scharge,

we may mention also

that it was

found

necessary to fit to

the

pipe an air valve o

pening

inwarda to

prev

ent the

waste

steam pipe, &c., from be

ing

filled with

water when

the

bl

owing

off of the

steam

ceased.

Of the remaining figures, Fig. 8

shows

one of Messrs.

J

Cockburn

and

Son's valves

loaded with dead weights, and

in

this case it will be seen a different form of relieving

disc is employed ; while Fig. 4 shows a spring-loaded valve.

Of course other modifications can

be arranged

to suit

various

circumstances.

Al toge

ther Messrs.

Cockburn and

Son's

valve is a very

simple

one,

and

it appears

in the

recent trials to have shown

an

e ffi ciency which en titles it to

special attention.

PROTECTION

FOR

INVENTIONS.

y

F. J .

B.IU.MWBLL,

C.E., F.R.S.

{O )Jitinued om page 483.)

BuT

in

the large class of inv entions, where the product is

an

improved one, and

the

very inspection

of

it reveals

the

improvement, secrecy is obviously imposeible. Let me, as

an

illustration, refer you to the Gitfard injector. Th is invention

(to which l shall again have to allude) is one applicable to

the supplying of steam boilers with their feed wa ter,

and

re

places the steam donkey pumps forme

rly

used for that

pu r

pose. The very first mechanical engineer into whose hands

one

of

these injectors came would take it to pieces,

and

at

once ucertain

the

nature

of

ita constr uction. In such

an

instance thie there can be no reward

by

secret manu

facture.

In the

caee I have aesumed, where it may pe

rhaps

be pos

sible for an inventor to carry on a secret

ma

nufacture, I have

taken (in favour of the adv ocates

of

such

a

syetem)

the

in

etance

of

a man having made an invention in hie own trade,

and being posseesed of every facility for b r i n ~ i n g that

in

vention to a commercial r esult ; but I believe it 111

not

among

inventors

and inventions

such

as these that we must look

for

great impr

ove

ments;

th

e fa

ct

is,

that the

bulk,

one

might almost say the whole, of r

eal

substantive inventions

have been made by persons not engaged

in

the particular

pu r

suit

to which thoee inventions relate.

Take

a few instances. Watt waa n

ot

a maker

of

steam

enginee, the fire-engines

of

hie day, but be was a

mathe

matical instrument maker ; Arkwright, the inventor

of the

'

1

wa ter twi

st,

wae a

barber;

Cartwnght,

the

inventor

of

the

power loom, w as a parso

n;

Neilaon,

the invento

r of the bot

blaet, was who

lly unc

onnected with

smelting

operations,

he

w s the manager of a gas worke;

Wheat

atone, who has done

so much for electric telegraphs , was engaged

in

the manu

facture of musical instrum

ents;

and Ronalde, the ver1 origi

nator

of the

electric telegraph,

ha

d nothing to do

WJth the

visual telegraphs

in

use

in

hie time; Beseemer, who has so

Paper

read before the Society of Arts.

enormously increased the

manufao

last quarter of a

century,

was in

no

industry. The fish.joint for railwa

ment

in permanent way

that has

were introduced, wae

the inventi

o

trust

I have given

inetances eno1

that the great

substantive inv(

unconnected with

the

manufa

inventions relate,

and

we can ,

The person who has been brou

manufacture hae even befor.

be able to appreciate the

pr

ocesses

he

was

taught

to

that

certain ends

are

to J.

U nder such circumstan

mind to break through

posed upon it, and '

subj

ec

t of the particv

aod power of dete

up

on which that .

mind

devoting it,

the

man untau

to

make a sub

trained

in

it

Improvew

there, in all

Ono

cat

from his l

tion,

that

containi'

to consi

ducing

m p r o ~

th

o

ugl

the trr

procet

mind

prob/

woul

11

ea

thin

tain

whe

wrc

cast

aeel

the

of

t

T

wou

7/23/2019 Eg 18741225

19/19

E N G I N E E R I N G

aid

of

n royalty it was poaaiblo for Bessemor to ob

y a small percentage on the price ot all steel, a sub-

.i l

reward, b11t

I

do not seo how tb1 . could hafe been

.rod to him by the profits derived from. being him

manufacturer of

that

which, oven on the

lar

geet

pmont

of

his works, could only have been a small

lo of the whole. The very magnit11de of the resulta

.ns invention would be a bar to an adeq11a l;e reward, unless

~ . n a t roward wore

sp

read over the whole manufacture.

, Thoro is ono other class of in v

ont

ion

s, th

e

nature

of which

.

renders

it

impossible for tho

pa t

entee to be adequately re

must warded (even under the most favourable circumstances) by

.acturer. manufacture. I will instance tho regenerative

f11rnaco

of

e d ~ o of Or. Siemens. This f11rnace, of wh ich thoro is a diarrram on

nt

in

sm

nlting the wall, has for ita object the

suing

of

f11

el and t h ~ attain

have

s11pp

osed, ing of h1gh heat. L ~ 1 1 d a b l objects

th

ose. Lot us seo how

1

and

the

many Dr

. Siemens attains the

m.

He makea a largo ohambor,

wo11ld know that called

th

e

11

Producer," capable

of

holding, say,

3

or

4

tons

th

e actual f11rnace of coal or ooke. At

th

e bottom of this chamber there is a

not be frustrated

by

small fire-grate,

imm

ediately above which a portion of the

>inventor to

do?

Forego

property which uauan,

..o

the erection of

an

expert

honour

of

n manufacture

r;

ink the probability is, he

and

that thus the invention

. minnry difficulty

of

a practi

?r example thaL he invention

lG Gifftud e c t o already

'ubst.an tivo of tbe prese

nt

day .

.1 priv11to by its inventor witho

ut

although

ho wero

wh

olly unco

n

~ b a n i c a l ar t

s, and

ho mig

ht

have

1

every detail.

But

when he

had

o beon hie chan co

of

reward, how

a ~ th,. pecuniary benefit which

1io .ould be his reasonable

du

e ?

:n( to forego all his usual habits of

t u r e r

1

that

in spite of

th

e difficulties

to

rt, he aucceeded in making a certain

for sale,

and th

at then he knew

cl

in purchasers for them, what would

As 1hav e already said, when taking

ment aa

C\

ne impossible

to

make the

ufacture, the ve

ry

first mechanical

J-

mak

er)

into

whose hands one of

i say,

11

H ere ia an implement that

.e se

ri

ously with

the

use of

steam

ot I

make it

P

At

present I know it

by the inve

nt

or onfy, a person who

o trade,

and

who is living in a pu rely

t is a hard case if cannot hold my own

o-

pump

mak

er goes to W

)

rk, with all

established factory, wi

th

its befitting

ntendenta,

it

s foremen,

and

ita body of

jectors, and with a whole system

of

d the advantage of a large connexion,

:s

when mad e.

~ b e inventor havo, in his capacity of

"gainst such an oganisation as this ?

,

aa it aeema to me (equally ob

is)

would I)Ot have beatowed tbe

t,

and

even if he had. he would not

\d expenao of experimenting upon

have) that in those caaea where

d be e&41rciaed by the inventor,

'l

rity

of inata110es would be

but

"'

D

a secret manufact11re,

it

is

r am about to d

o,

that thoro

h (whatever might be the

uds

command of capital,

n nppropriate locality) it

1\ture of

thing

s for him to

=nt on railways. This

ing out, at each joi

nt

nuts. Those can be

o

rld, witho

11t the

) ; they

ar

e mere

1plied to raila in

after years of

hnittodly de

If ,

it makes

Nay

and

of

ree to the

fuel is unde rgoing comb11stion in

th

e ordinary manner . The

heated carbonic acid r es11lting passes up th ro11gh thq fuel ,

takes up carbon from it, becomes conve

rt

ed in to carbonic

oxide, and escapee

(with any hydr

o-carbon that may have

boon driven oil' by

th

e heat, if the fuel be coal)

th r

o

ugh

an

ascending pipe, an d is led nway by mains to any place where

a regenerative furnace is to be in operation. 1.he regene

rative furnace has below it two pairs of stacks of cell11lar, or

pigeon hole, brickwork. Thro11gh one division of one

pair

tbo ~ a s from the prod11cor is asoonding; th rough

th

e other

divistoo of the aame J>&ir atmospheric

air

is also ascending ;

the air

nod

gas

m

oo

t m the chamber of the f11rnace, comb l1s

tion ens es, and

heat it

developed.

In an

ordinary furnace

tho heated products of combustion escape int o the nir by a

chimney, and, as they

mu

st loafe the f11rnace

at

a higher

tempera

t11

re

than

that

at

which

it

is necessa

ry

to

ma

intain

the material under operation (or otherwise they w

o11

ld cool

that material), the prod cts of comb11stion of ord inary fur

naces must in all cues whore high temperatures are neces

sary, carry in to the air, and wa

st

e a large amo11nt of heat.

Bllt in tho Siemens' furnace those 011tgoing prod11cts are

compelled, on their way to

th

o chimney, to pass downwar

ds

thr ough

the tw

o divisions of the second pair of blocks of

pigeon-hole br ickwork, anti i n th eir passage they give up

th

eir heat to

th

is brickwork 10 ell'octually that, altho gh

th

ey may have been ias11ing from a furnace above

th

e tom

perat l1re of melted steel, they will, on reaching

the

chimney,

not have heat enough remaining in them to char a piece of

woo d. At the e

nd

of a certain time, say

half

or

th

ree

quarters of an hour, valves, which control

the

dire

ct

ion of

the

o11rrents

of gas a nd air,

and

of the 1 1 t ~ i n g

pr

od11cts of

combustion, are shifted, and the gas and atr are now caused

to ascend th rough the pair of masses of cellwar brickwork

wh ich have

just

been heated by the outgoing pro

dl.l

ete of

combustio

n,

while those prod cts are directed downwar

ds

th ro gh the other pair of cellular str11ct11re

s,

which have

been cooled by

the

pa

ss

age thro11gh

them

of

th

e gas and air,

and thus are fit, being cool, to take out from

th

e prod cts of

combustion tho heat which is in them,

and

to store it to heat

p the gas and air, when they, on the next reversal

of

tbe

vatves, again pass thro1gh them.

The success of this plan has been complete;

th

e adnn

tarres

in

economy of fuel, and

in th

o capacity to

iive

high

ho';.t , b a v ~ been all that

co

uld be desired. Mo

rc>

ovor, thoro

are

larg

o contingent benefits, into

wh

ich

I

will

not

:ab tlr

enter. No one will dispute that this i.

o

IXlost meruorie'*

inven tion; it eaves o11r coal,

and

it renders possible eeat 'ill

processes, which, with the temperat11ros formerly attaiqa,bl9,

coulll not bo carried

011t. But

how, in the absence of pro-

tection for inventio

n,

co

11ld

Dr. Siement have derived any

adeq11a te .-award ?

Not

by practising his invention, for that,

from the very universality of its application, would have

been an imJ?ossibility. Hie furnaces are used by

the

manu

fac

tl1

rors of wro11ght

ir

on, by the makers of

stee

l, by the

pr

od 11cers of plate

and

flint glas11, by enamellers, by

copp

er

smelters, by nail makers, potters,

and

by those engaged in

o11mero11s other branches of industry requiring f11rnaco

power.

1 should like to

ask th

e adv

oc

ates of

the

eyetem of re

warding inventors, by letting

th

em carry out,

as

manufac

tl1rors, the objects of their invention, whether they would

suggest that Dr. Siemens waa to embark in all

the

b l1si

nessea to which his invention is applicable. They might say,

11

No; we never in tended anything eo absurd.

His

inven

tion is a f11rnace, and he should embark in the manufacture

of furna

ce

s,

as the inventor of an improved loom should

embark in

the manu

facture of l

oo ms

.

B11t the answer to

tbi