CHAPTER 15. Steam Hammer Pile-driver.

In 1840 I furnished Sir Edward Parry with a drawing of my steam hammer,

in the hope that I might induce him to recommend its adoption in the

Royal Dockyards. Sir Edward was at that time the head director of the

steam marine of England. That was after the celebrity he had acquired

through his Arctic voyages. I was of opinion that the hammer might

prove exceedingly useful in forging anchors and large iron work in

those great establishments. Sir Edward appeared to be much struck with

the simplicity and probable efficiency of the invention.

But the Admiralty Board were very averse to introducing new methods of

manufacturing into the dockyards. Accordingly, my interview with

Sir Edward Parry, notwithstanding his good opinion, proved fruitless.

Time passed by. I had furnished steam hammers to the principal

foundries in England. I had sent them abroad, even to Russia.

At length it became known to the Lords of the Admiralty that a new

power in forging had been introduced. This was in 1843, three years

after I had submitted my design to Sir Edward Parry. The result was

that my Lords appointed a deputation of intelligent officers to visit

my foundry at Patricroft to see the new invention. It consisted of

Captain Benison (brother of the late Speaker), and Captain Burgman,

Resident Engineer at Devonport Dockyard. They were well able to

understand the powerful agency of the steam hammer for marine forge

work. I gave them every opportunity for observing its action.

They were much pleased, and I may add astonished, at its range, power,

and docility.

Besides showing them my own steam hammer, I took the deputation to the

extensive works of Messrs. Rushton and Eckersley, where they saw one

of my five-ton hammer-block steam hammers in full action.

It was hammering out some wrought-iron forgings of the largest class,

as well as working upon smaller forgings. By exhibiting the wide range

of power of the steam hammer, these gentlemen were entirely satisfied

of its fitness for all classes of forgings for the naval service.

They reported to the Admiralty accordingly, and in a few days we

received an official letter, with an order for a steam hammer having

a 50 cwt. hammer-block, together with the appropriate boiler,

crane, and forge furnace, so as to equip a complete forge shop at

Devonport Dockyard. This was my first order from the Government for

a steam hammer.

When everything was ready, I set out for Devonport to see the hammer

and the other portions of the machinery carefully erected.

In about a fortnight it was ready for its first stroke. As good luck

would have it, the Lords of the Admiralty were making their annual

visit of inspection to the dockyard that day. They arrived too late in

the afternoon for a general inspection of the establishment; but they

asked the superintending admiral if there was anything of importance

which they might see before the day closed. The admiral told them that

the most interesting novelty in the dockyard was the starting of

Nasmyth's steam hammer. "Very well, they said, "let us go and see that".

I was there, with the two mechanics I had brought with me from

Patricroft to erect the steam hammer. I took share and share alike in

the work. The Lords were introduced to me, and I proceeded to show

them the hammer. I passed it through its paces. I made it break an

eggshell in a wine-glass without injuring the glass. It was as neatly

effected by the two-and-a-half ton hammer as if it had been done by an

egg-spoon. Then I had a great mass of white-hot iron swung out of the

furnace by a crane and placed upon the anvil block. Down came the

hammer on it with ponderous blows. My Lords scattered to the

extremities of the workshop, for the splashes and sparks of hot metal

flew about. I went on with the hurtling blows of the hammer,

and kneaded the mass of iron as if it had been clay into its devised

forms.

After finishing off the forging, my Lords gathered round the hammer

again, when I explained to them the rationale of its working,

and the details of its construction. They were greatly interested,

especially Mr. Sidney Herbert (afterwards Lord Herbert of Lea),

then Secretary to the Admiralty, and Sir George Cockburn,

a fine specimen of the old admiral. Indeed, all the members of the

Board were more or less remarkable men. They honoured me with their

careful attention, and expressed their admiration at the hammer's

wonderful range of power and delicacy of touch, in this new application

of the force of steam.

The afternoon was a most important one for me in more ways than one,

although I cannot venture to trouble my readers with the details.

It was followed, however, by an order to supply all the Royal Dockyard

forge departments with a complete equipment of steam hammers,

and all the requisite accessories. These were supplied in due time,

and gave in every case the highest satisfaction. The forgings were

found to be greatly better, and almost absurdly cheaper than those done

by the old bit by bit building-up process. The danger of flaws was

entirely done away with; and, in the case of anchors, this was a

consideration of life and death to the seamen, who depend for their

safety upon the soundness of the forgings.

Besides my introduction to that admirable man, Mr. Sidney Herbert,

I had the happiness of being introduced to Captain Brandreth,

Director of Naval Works. The whole of the buildings on shore,

including the dockyards, were under his control. One of the most

important affairs that the Lords of the Admiralty had to attend to on

their visit to Devonport was to conclude the contract for constructing

the great docks at Keyham. This was a large extension of the Devonport

Docks, intended for the accommodation of the great steamships of the

Royal Navy, as well as for an increase of the graving docks and

workshops for their repair. An immense portion of the shore of the

Hamoaze had to be walled in so as to exclude the tide and enable the

space to be utilised for the above purposes. To effect this a vast

amount of pile-driving was rendered necessary, in order to form a firm

foundation for the great outer dock wall, about a mile and a quarter in

length.

Messrs. Baker and Sons were the contractors for this work.

They were present at the first start of my steam hammer at Devonport.

They were, like the others, much impressed by its vast power and

manageableness. They had an interview with me as to its applicability

for driving piles for the immense dock, this being an important part of

their contract. Happily, I had already given some attention to this

application of the powers of the steam hammer. In fact, I had secured

a patent for it. I had the drawings for the steam hammer pile-driving

machine with me. I submitted them to Mr. Baker, and he saw its

importance in a moment. "That," he 'said, "is the very thing that I

want to enable me to complete my contract satisfactorily." Thousands of

enormous piles had to be driven down into the deep silt of the Shore;

and to have driven them down by the old system of pile-driving would

have occupied a long time, and would also have been very expensive.

The drawings were of course submitted to Captain Brandreth.

He was delighted with my design. The steam pile-driver would be,

in his opinion, the prime agent for effecting the commencement of the

great work originated by himself. At first the feat of damming out

such a high tide as that of the Hamoaze seemed very doubtful, because

the stiff slate silt was a treacherous and difficult material to

penetrate. But now, he thought, the driving would be rendered

comparatively easy. With Captain Brandreth's consent the contractors

ordered of me two of my steam hammer pile-drivers. They were to be

capable of driving 18-inch square piles of 70 feet in length into the

silt of the Hamoaze.

[Image] Space to be enclosed at the Hamoaze

This first order for my pile-driver was a source of great pleasure to me.

I had long contemplated this application of the power of the steam

hammer. The machine had long been in full action in my "mind's eye,"

and now I was to see it in actual reality. I wrote down to my partner

by that night's post informing him of the happy circumstance. The order

was for two grand steam hammer pile-drivers, each with four-ton

hammer-blocks.The wrought-iron guide case and the steam cylinder were

to weigh in all seven tons. All this weight was to rest on the

shoulders of the pile. The blows were to be about eighty in the

minute. This, I thought, would prove thoroughly effective in rapidly

driving the piles down into the earth.

I have said that the steam pile-driver was in my mind's eye long before

I saw it in action. It is one of the most delightful results of the

possession of the constructive faculty, that one can build up in the

mind mechanical structures and set them to work in imagination, and

observe beforehand the various details performing their respective

functions, as if they were in absolute material form and action.

Unless this happy faculty exists ab initio in the brain of the

mechanical engineer, he will have a hard and disappointing life before

him. It is the early cultivation of the imagination which gives the

right flexibility to the thinking faculties. Thus business, commerce,

and mechanics are all the better for a little healthy imagination.

So soon as I had returned home, I set to work and prepared the working

drawings of the steam pile-drivers. They were soon completed, conveyed

to Devonport, and erected on the spot where they were to be used.

They were ready on the 3d of July 1845. Some preliminary pile-driving

had been done in the usual way, in order to make a stage or elevated

way for my pile-driver to travel along the space where the permanent

piles were to be driven. I arranged my machines so that they might

travel by their own locomotive powers along the whole length of the

coffer dam, and also that they should hoist up the great logs of Baltic

timber which formed the Piles into their proper places before being

driven.

The entire apparatus of the machine was erected on a strong timber

platform, and was placed on wheels, so that it might move along the

rails laid down upon the timber way. The same boiler that supplied the

steam hammer part of the apparatus served to work the small steam-engine

fixed to the platform for its locomotion, and also to perform the duty

of rearing the next pile which had to be driven. The steam was

conveyed to the hammer cylinder by the jointed pipe seen in the annexed

engraving. The pipe accommodated itself to any elevation or descent of

the hammer. The whole weight of the cylinder, hammer-block, and guide

box, supported by the shoulders of the pile, amounting to seven tons in

all, rested upon the shoulders of the pile as a "persuader;" and the

eighty blows per minute of the four-ton hammer came down with

tremendous energy upon the top of the pile head. No soil, that piles

could penetrate, could resist such effective agencies.

[Image] Diagram of the Steam Pile-Driver

Explanation of the Diagram of the Steam Pile-Driver.--The chief

feature of novelty of this pile-driving machine consists in the

employment of the direct action of the Steam Hammer as the blow giving

agent, and also in the manner in which the dead weight of the entire

apparatus, consisting of the hammer-block C, the steam cylinder A,

and its guide-case B, is employed to importantly aid the effect of the

rapid and energetic blows of the steam hammer. These ponderous parts

rest on the shoulders of the pile H all the while it is being driven,

the pile in this respect being the only support of the apparatus A B C.

So that, besides the eighty blows per minute that the four-ton steam

hammer energetically deals out to the head of the pile from a four foot

fall the dead weight of the apparatus constantly acts as a most

effective "predisposer" to the sinking of the pile into the ground; the

hoisting chain D being let slack the while, so as to allow A B C to

"follow down" the pile H, while the eighty blows per minute are

incessantly showered on its head. The upward stroke of the piston,

with its attached hammer-block C, is arrested at the proper height not

only by allowing the steam that raised it to escape, but as soon as the

piston passes the escape holes X X, the confined air above the piston

at O rebounds, and so aids most effectively in increasing the energy of

the fall of the hammer-block C on the pile head.

There was a great deal of curiosity in the dockyard as to the action of

the new machine. The pile-driving machine-men gave me a good-natured

challenge to vie with them in driving down a pile. They adopted the

old method, while I adopted the new one. The resident managers sought

out two great pile logs of equal size and length--70 feet long and

18 inches square. At a given signal we started together.

I let in the steam, and the hammer at once began to work. The four-ton

block showered down blows at the rate of eighty a minute;

and in the course of four and a half minutes my pile was driven down to

the required depth. The men working at the ordinary machine had only

begun to drive. It took them upwards of twelve hours to complete the

driving of their pile!

Such a saving of time in the performance of similar work--by steam

versus manual labour--had never before been witnessed.

The energetic action of the steam hammer, sitting on the shoulders of

the pile high up aloft, and following it suddenly down, the rapidly

hammered blows keeping time with the flashing out of "the waste steam

at the end of each stroke, was indeed a remarkable sight. When my pile

was driven, the hammer-block and guide case were speedily re-hoisted by

the small engine that did all the labouring and locomotive work of the

machine; the steam hammer portion of which was then lowered on to the

shoulders of the next pile in succession. Again it set to work.

At this the spectators crowding about in boats, pronounced their

approval in the usual British style of "three cheers!"

My new pile-driver was thus acknowledged as another triumphant proof of

the power of steam.

The whole of the piles for this great work were speedily driven in.

The wall was constructed, and the docks were completed in an unusually

short time. The success of my pile-driver was followed by numerous

orders. It was used for driving the immense piles required for the

High Level Bridge at Newcastle, the great Border Bridge at

Berwick-upon-tweed, the Docks at Tynemouth, the Docks at Birkenhead,

the Docks at Grimsby, the new Westminster Bridge, the great bridge at

Kief in Russia, the bridge at Petersburg, the forts at Cronstadt,

the Embarrage of the Nile, at Yokohama in Japan, and at other places.

It enabled a solid foundation to be laid for the enormous

superstructures erected over them, and thus contributed to the

permanence of many important undertakings.

The mechanical principles on which the efficiency of the steam

pile-driver chiefly depends are as simple as I believe they are

entirely novel and original. The shoulder of the pile acts as the sole

supporter of the ponderous mass of the hammer-block, cylinder,

and guide-box. This heavy weight acts as a predisposing agency to

force the pile down, while the momentum given by the repeated fall of

the hammer, at eighty blows the minute, brings the constant dead weight

into full action. I am not aware of any other machine in which such a

combination of mechanical forces is employed.

Another very effective detail consisted in employing the waste steam in

the upper part of the cylinder for the purpose of acting as a buffer to

resist any undue length of the upward stroke of the piston.

But for this the cylinder covers might have been knocked off.

The elastic buffer of waste steam also acted as a help to the downward

blow of the hammer-block. The simplicity and effectiveness of these

arrangements form--if I may be allowed to say so--a happy

illustration of my "Definition of Engineering," the application of

common sense in the use of materials.

The folding-up steam pipe with which the steam was conveyed from the

boiler to the cylinder at all heights, and the way in which the folding

joints accommodated themselves to the varying height of the cylinder,

was another of my happy thoughts. In fact, this invention, like most

others, was the result of a succession of happy thoughts.

The machine in its entirety was the result of a number of common-sense

contrivances, such as I generally delight in. At all events, this most

effective and novel machine was a special favourite with me.

I may mention, before concluding this branch of my subject,

that pile-driving had before been conducted on what I might term the

artillery or cannon-ball principle. A small mass of iron was drawn

slowly up, and suddenly let down on the head of the pile at a high

velocity. This was destructive, not impulsive action. Sometimes the

pile was shivered into splinters, without driving it into the soil;

in many cases the head of the pile was shattered into matches, and this

in spite of a hoop of iron about it to keep the layers of wood

together. Yet the whole was soon beat into a sort of brush.

Indeed, a great portion of the men's time was consumed in "reheading"

the piles. On the contrary, I employed great mass and moderate

velocity. The fall of the steam hammer-block was only three or four

feet, but it went on at eighty blows the minute, and the soil into

which the pile was driven never had time to grip or thrust it up--

an impediment well known to ordinary pile-drivers. At the end of the

driving by my steam hammer, the top of the pile was always found neat

and smooth, indeed more so than when the driving began.

I may again revert to my interview with the Lords of the Admiralty on

the occasion of my first meeting them at Devonport. I was residing at

the hotel where they usually took up their quarters while making their

annual visitation of the dockyard. I was honoured with an invitation

to confer with Sir George Cockburn, Mr. Sidney Herbert, and Captain

Brandreth on a subject of considerable importance; namely, the proving

of chain cables and anchors required for the Royal Navy. The question

was mooted as to whether or not some permanent injury was done to both

by the test strains to which they were submitted before being put on

board ship. This was a subject of vital importance. The members of

the Board requested me to act as one of a committee to inquire into the

subject. I felt much gratified by the invitation and gladly accepted

it.

On discussing the subject with these gentlemen that evening, I found

that Sir George Cockburn entertained an ingenious theory in support of

his apprehensions as the effect of "over-proof" straining of cables and

anchors. It was that they were originally in the condition of a strong

man who had to lift some heavy weight, requiring him to exert his

muscular strength to the utmost; and, although he might perform the

feat, it was at the cost of a permanent injury, and that he might never

be able to lift the same weight again. This, however true it might be

with regard to flesh and bone structures, was scarcely true with

respect to mechanical agencies. I proposed a simple experiment with

chain cables, which, it occurred to me, would show quite a different

result--namely, that the capability of resisting the severest

proof-strain would rise rather than fall at each successive proof of

the same chain cable.

To test the correctness of my supposition, we had a first-class chain

cable put into the proof machine,and subjected it to such a strain as

to break it again and again, until at last it was divided almost into

single links. As I expected, the proof or breaking strain kept rising

and rising as each successive remaining portion of the cable was torn

asunder, thus showing that no injury to the natural tenacity of the

chain had resulted from the increased proofs to which it had been

subjected, and that the last broken links had been much more resisting

than the first. The same class of demonstrative experiments was made

with anchors, and other wrought-iron work used in the service.

The Admiralty officers were much gratified with the result, as removing

a groundless but very natural apprehension, heightened, no doubt,

by the suggestions that had been made to the Admiralty, that their

standard proof strain was not only too high in itself, but produced

permanent damage to what at the outset was of the toughest iron.

My system of continued proof-straining was, in fact, another

exemplification of the "Survival of the Fittest"!

A very interesting truth came out in the course of our experiments.

It was that the chief cause of failure in the links of chain cables

arose, not so much from their want of tenacity, or from the quality of

the iron, but from some defective welding in the making of the links.

To get at this truth, many excellent cables as received from the

contractors, as well as veteran ones that had held great ships riding

at anchor in terrible gales, were pulled asunder link by link by an

intentional destructive strain by the proving machine.

An exact account was taken of the nature of the fracture of each.

The result was that in eight cases out of ten, the fracture was found

to result from a defectively welded part of the chain-link.

The practically trained eye could see the scoria which indicates the

defective welding. Though long unseen, it was betrayed at once when

the link was torn open by the proof strain.

My services on this committee proved a source of great enjoyment to me.

I had frequent occasion to visit the dockyards and workshops,

accompanied by Captain Brandreth, surveyor-general of the Admiralty

landworks,Mr. Thomas Lloyd, engineer-in-chief of the Admiralty, and

Mr. Jeremiah Owen, chief of the metal material required in the

equipment of the navy I was requested to suggest any improvement in the

workshops that I thought would add to the efficiency of the department;

and I trust that my recommendations proved of practical good to the

service. At the same time, I have reason to know that many of the

recommendations of the committee, though cordially acknowledged by the

higher powers, were by a sort of passive resistance practically

shelved.

I was much amused, when I first went to Devonport dockyard, to notice

the punctilious observance of forms and ceremonies with respect to the

various positions of officials--from the admiral-superintendent down

the official grades of dignity, to the foremen of departments,

and so on. I did not care for all this panjandrum of punctiliousness,

but was, I hope, civil and chatty with everybody. I had a good word

for the man as well as for the foreman. I received some kind and

good-natured hints as to the relative official superiority that

prevailed in the departments, and made out a scale or list of the

various strata accordingly. This gamut of eminence was of use to me in

my dealings with dockyard officials. I was enabled to mind my p's and

q's in communicating with them.

The first Sunday that I spent at Devonport I went to the dockyard

church--the church appointed for officials and men employed by the

Government. The seats were appointed in the order of rank,

employments, and rate of pay. The rows of seats were all marked with

the class of employers that were expected to sit in them. Labourers

were near the door. The others were in successive rows forward,

until the pew of the "Admiral Superintendent," next the Altar rails,

was reached. I took my seat among the "artificers," being of that

order. On coming out of church the master-attendant, next in dignity to

the admiral-superintendent, came up to me to say how distressed he was

to see me "among the artificers," and begged me in future to use his

seat. No doubt this was kindly intended, and I thanked him for his

courtesy. Nevertheless I kept to my class of artificers.

I did not like the "breest o' the laft'"*

[footnote...

The breest o' the laft is the seat of dignity. The best places in

churches are occupied by "superior" people. In Scotland the chief men

--the Provosts, Bailies, and Councillors--have a seat appropriated to

them in the front part of the gallery, generally opposite the minister.

That is "the breest o' the laft."

The same principle pervades society generally.

...]

principle. No doubt the love of distinction, within reasonable limits,

is a great social prime mover; but at Devonport, with the splitting up

into ranks, even amongst workmen, I found it simply amusing, especially

when introduced into a church.

I afterwards met with several veterans in the service of the Admiralty,

who are well served by such experienced and well-selected men.

It is the schemers and the satellites who haunt the contractors that

are the vermin of dockyards. I gave them all a very wide berth.

But worst of all are the men who get their employment through

parliamentary influence. They are a detestable set. They always have

some "grievance" to pester people about. I hope things are better now.

I may add, with respect to the steam hammer pile-driving machines,

that I received an order for two of them from Mohammed Ali, the Pasha

of Egypt. These were required for driving the piles in that great work

--the barrage of the Nile near Cairo. The good services of these

machines so pleased the Pasha that he requested us to receive three

selected Arab men into our works. He asked that they should have the

opportunity of observing the machinery processes and the system of

management of an English engineering factory. The object of the Pasha

was that the men should return to Egypt and there establish an engine

manufactory, so as to render him in a measure independent of foreign

help. For British workmen, when imported into Egypt, had a great

tendency to degenerate when removed from the wholesome stimulus to

exertion in competition with their fellows.

My firm had no objection to the introduction of the Arab workmen.

Accordingly, one day we received a visit from an excellent Egyptian

officer, Edim Bey, accompanied by his secretary Rushdi Effendi,

who spoke English fluently. He thus made our interview with the Bey

easy and agreeable. He conveyed to us, in the most courteous manner,

the wishes of the Pasha; and the three workmen were at once received.

Every opportunity was given them to observe and understand the works

going forward. They were intelligent-looking young men, about

twenty-five years of age. One of them was especially bright looking,

quick in the expression of his eyes, and active in his manner,

His name was Affiffi Lalli; the names of the others I forget.

These young men were placed under charge of the foremen of the

departments that each fancied to be most to his taste. Affiffi was

placed in the fitting department, in which skilful manipulation was

required. He exhibited remarkable aptitude, and was soon able to hold

his own alongside of our best workmen. Another was set to the turning

department, and did fairly well. The third was placed in the foundry,

where he soon became efficient in moulding and casting brass and iron

work. He lent a hand all round, and picked up a real practical

knowledge of the various work in his department. During their sojourn

in our works they became friendly with their colleagues; and in fact

became quite favourites with the men, who were always willing to help

them. But Affiffi Lalli was regarded as the genius of the trio.

He showed a marked and intelligent aptitude for acquiring technical

skill in all the branches of our business.

After remaining with us for about four years they were ready to return

to Cairo, and show what they had learned in practical and technical

mechanical knowledge during their stay in England. The three Arab

workmen were placed in their suitable departments in the Pasha's work

shops. But such was the natural energy of Affiffi, that when he was

set to work beside the slow, dilatory, and stupid native workmen,

he became greatly irritated. The contrast between the active energetic

movements which he had seen at the Bridgewater Foundry and the

ineffective, blundering, and untechnical work of his fellows was such

that he could not stand it any longer. So one fine day he disappeared

from the works, took refuge on board a British steamer, and at the risk

of his neck made his way back to the Bridgewater Foundry!

As we were reluctant to take back a man who had escaped from the

Pasha's employment--excellent workman though he was--we declined to

employ him. But I gave Affiffi a note of introduction to Boulton and

Watt of Soho, Birmingham, and there he was employed. He afterwards

passed into other firms, and having employed his skill in making some

needle machinery at Redditch, he settled down there. He married a

Warwickshire lass, and had a family--half Arab, half English--

and has now a thriving foundry and engineer workshop of his own.

This little narrative shows that the Arab has still much of the

wonderful energy and skill that once made the Moors masters of a large

part of South-Western Europe.

We had many visitors at the foundry--from London,

from the manufacturing districts, and from foreign countries.

One day a young gentleman presented a letter from Michael Faraday,

dated "Royal Institution, 29th May 1847," requesting me to pay him some

attention and show him round the works. I did so with all my heart,

and wrote to Mr. Faraday intimating how much pleasure it gave me to

serve him in any respect. I cannot refrain from giving his answer.

He said:

"MY DEAR SIR--That you should both show kindness to the bearer of my

letter, and prove that you did so with pleasure by writing me a letter

in return, was indeed more than I ought or could have expected;

but it was very gratifying and pleasant to my mind. I only wish that

the circumstances of my life were such as to enable me to take

advantage of such goodwill on your part, and to be more in your company

and conversation than is at present possible.

"I could imagine great pleasure from such a condition of things;

but though our desires, and even our hopes at times spread out

beforehand over a large extent, it is wonderful how, as the future

becomes the present, the circumstances that surround us limit the

sphere to which our real life is circumscribed If ever I come your way

I hope to see your face; and the hope is pleasant, though the reality

may never arrive.

"You tell me of the glorious work of your pile-driver, and it must be

indeed a great pleasure to witness the result. Is it not Shakespeare

who says, 'The pleasure we delight in physics pain'? In all your

fatigue and labour you must have this pleasure in abundance, and a most

delightful and healthy enjoyment it is. I shall rejoice to see some

day a blow of the driver and a tap of the hammer.

"You speak of some experiments on hardening and tempering steel in

which we can help you. I hope when you do come to town you will let us

have the pleasure of doing so. Our apparatus, such as it is, shall be

entirely at your service. I made, a long while ago, a few such

experiments on steel wire, but could eliminate no distinct or peculiar

results. You will know how to look at things, and at your hand I

should expect much.

"Here we are just lecturing away, and I am too tired to attempt

anything, much less to do anything just now; but the goodwill of such

men as you is a great stimulus, and will, I trust even with me,

produce something else praiseworthy.

Ever, my dear Nasmyth, yours most truly, M. FARADAY."

James Nasmyth, Engineer: An Autobiography · 第 15 / 22 章