CHAPTER XIX_Engineering reminiscences contributed to "Power" and "American machinist"

Boiler Tests in Exhibition of 1871. We Lose Mr. Allen. Importance of

Having a Business Man as President. Devotion of Mr. Hope.

The next year we were not exhibitors at the Institute fair, but our

boiler remained in its place and was run by the Institute. This boiler

and its setting are shown correctly in the accompanying reproduction

of a drawing made about that time, except that it consisted of nine

sections instead of six. At the close of the exhibition a boiler test

was made by the Institute, through a committee of which Professor

Thurston, at that time Professor of Mechanical Engineering in the

Stevens Institute, afterwards until his death Director of the Sibley

College of Mechanic Arts, in Cornell University, was the chairman. Five

boilers, including the Allen boiler, were tested, one on each day, in

a continuous run of twelve hours. The four besides our own were all

different from the boilers exhibited the year before.

A week was spent in preparation for this test. A large wooden tank was

constructed, in which was built a surface condenser, consisting of a

pile of sections of the Root boiler, laid horizontally, having a total

of 1100 square feet of cooling surface. The steam was exhausted into

the pipes which were surrounded by the cooling water, thus reversing

the construction of surface condensers.

[Illustration: Professor ROBERT H. THURSTON]

[Illustration:

ALLEN BOILER.

80 HORSE POWERS.

_Area of Effective Heating Surface 810-Square Feet._

_ „ „ Grate „ 24 „ „_

_scale-1 inch-1 foot._

_Allen Engine Works._

_July-1872._]

Each boiler was tested by setting its damper and its steam-valve wide

open, so burning all the coal that could be burned by it under its

draft, and delivering freely all the steam that it made. This latter

entered the condenser at the top, and the water formed by condensation

was drawn off at the bottom, while the condensing water entered the

tank at the bottom and was drawn off at the top, the currents of

steam and water being thus opposite to each other, which was an ideal

construction. The condensing water at a temperature of 45.5 degrees

flowed in under the pressure in the city main and was measured in a

Worthington meter, and the temperature of the overflow taken. The

condensed steam was drawn off into a barrel and weighed, 300 pounds at

a time, and its temperature taken. This method was an excellent one.

Not having high chimneys, no boiler had a strong draft, as shown by the

coal burned per square foot of grate. Our draft was the strongest of

all. Only the Allen boiler and the Root boiler gave superheated steam,

and the competition between them was very close. The valve being wide

open, giving a free current into the condenser, the superheat of our

steam fell to 13.23 degrees Fahrenheit. Root’s superheat was 16.08

degrees.

Root’s boiler, the trial of which occupied the first day, blew steam

from the open try-cock, from water at 46 degrees Fahrenheit, in sixteen

minutes from lighting the fire. Next morning our boiler blew steam from

water at the same temperature, in twelve minutes, and Mr. Root holding

his watch could not resist the ejaculation, “Wonderful boiler!” The

Allen boiler, burning 13.88 pounds of coal per square foot of grate

per hour, evaporated one cubic foot of water per hour from each 17.41

square feet of heating surface. Root’s boiler, burning 11.73 pounds of

coal per square foot of grate per hour, required 23.59 square feet of

heating surface to evaporate one cubic foot of water per hour.

Our stronger draft, 13.88 against 11.73, accounted for 3.2 pounds of

the above superior evaporative efficiency, leaving 3 pounds to be

accounted for by the more rapid circulation in the Allen boiler. The

great value of the inclination of the tubes was thus established. The

report contains this sentence: “The Committee desire to express their

appreciation of the excellent general arrangement and proportions which

gave to the Allen boiler its remarkably high steaming capacity.”

The reader will observe in the plan of this boiler the pains taken

to maintain as far as possible parallel currents of the heated gases

through the boiler, and taking the flues off at the bottom, thus

bringing all the heating surfaces at the same distance from the furnace

into approximately equal efficiency.

RESULTS OF THE COMPETITIVE TRIAL OF STEAM BOILERS AT THE FAIR OF THE

AMERICAN INSTITUTE, NOVEMBER, 1871.

---------+-----------------+--------+

| | |

| Square Feet. | |

+--------+--------+ |

| | | |

| | | Ratio |

| | | of |

| | | heating|

| | | surface|

| | | to |

| Grate | Heating| grate |

Name. |surface.|surface.|surface.|

---------+--------+--------+--------+

| A. | B. | C. |

Root | 27 | 876¹⁄₂ | 32.5 |

Allen | 32¹⁄₄ | 920 | 28.5 |

Phleger | 23 | 600 | 26.1 |

Lowe | 37³⁄₄ | 913 | 24.2 |

Blanchard| 8¹⁄₂ | 440 | 51.8 |

---------+--------+--------+--------+

---------+----------------------------------------+------+

| | |

| Total Weights. | |

+-----+---------+-------+--------+-------+ |

| | | | | | of |

| | | | | | to |

---------+-----+---------+-------+--------+-------+------+

| D. | E. | F. | G. | H. | I. |

Root | 3800| 3185.5 |27896 |27896 | 0. | 0. |

Allen | 5375| 4527 |39670 |39670 | 0. | 0. |

Phleger | 2800| 2274 |20428 |19782.94| 645.06| 3.26 |

Lowe | 4400| 3705 |34000 |31663.35|2336.65| 6.9 |

Blanchard| 1232| 1047.5 |10152.5| 9855.6 | 296.9 | 3. |

---------+-----+---------+-------+--------+-------+------+

---------+----------------------------------------------------+

| |

| Mean Temperatures. |

+------+------+-------+-------+-------+------+-------+

| | | | | | | |

| | | of | | | | |

---------+------+------+-------+-------+-------+------+-------+

| J. | K. | L. | M. | N. | O. | P. |

Root |45°.94|45°.94| 58°.31|143°.1 |334°.6 |16°.08|416°.6 |

Allen |45°.5 |45°.5 | 63°.48|154°.76|330°.63|13°.23|345°.87|

Phleger |45°.65|45°.65| 54°.38|120°.83|321°.06| 0°. |503°.76|

Lowe |45°.0 |45°.0 | 54°.8 |131°.5 |319°.48| 0°. |389°.6 |

Blanchard|44°.4 |44°.4 | 49°.49|106°.14|323°.75| 0°. |221°.67|

---------+------+------+-------+-------+-------+------+-------+

---------+--------------+---------+

| | |

| | Total |

| | units |

| | per |

| Total | pound |

| British | of |

| thermal | com- |

Name. | units. |bustible.|

---------+--------------+---------+

| Q. | R. |

Root |32,751,834.34 |10,281.53|

Allen |46,387,827.1 |10,246.92|

Phleger |23,066,685.39 |10,143.66|

Lowe |37,228,739.072|10,048.24|

Blanchard|11,485,777.35 |10,964.94|

---------+--------------+---------+

---------+-------------------------------+---------------+

| | Actual |

| Apparent Evaporation. | Evaporation. |

+-----+---------+-------+-------+-----+---------+

| | | | | | |

| | | Per | Per | | |

| | Per |foot of|foot of| | Per |

| of | com- | per | per | of | com- |

---------+-----+---------+-------+-------+-----+---------+

| S. | T. | U. | V. | W. | X. |

Root | 7.34| 8.76 | 86.09| 2.65 | 7.34| 8.76 |

Allen | 7.38| 8.76 | 102.51| 3.59 | 7.38| 8.76 |

Phleger | 7.26| 8.95 | 73.70| 2.83 | 7.07| 8.70 |

Lowe | 7.68| 9.12 | 75.06| 3.10 | 7.20| 8.55 |

Blanchard| 8.24| 9.69 | 99.53| 1.92 | 8.00| 9.41 |

---------+-----+---------+-------+-------+-----+---------+

---------+---------+----------+-------+--------

| | | |

| Equiv- | Square | | Effi-

| alent | feet | Coal, | ciency;

| evapo- |of heating| lbs. | actual

| ration | surface | per | evapo-

| of water| required | square| ration

| at 212° | to evapo-| foot, | of fuel

|Fahr. and| rate one | grate | divided

| atmos- |cubic foot|surface| by

| pheric | of water | per | theo-

Name. |pressure.| per hour.| hour. |retical.

---------+---------+----------+-------+--------

| Y. | Z. | Z. 1 | Z. 2

Root | 10.64 | 23.59 | 11.73 | 0.709

Allen | 10.60 | 17.41 | 13.88 | 0.707

Phleger | 10.49 | 22.74 | 10.13 | 0.699

Lowe | 10.40 | 21.63 | 9.71 | 0.693

Blanchard| 11.34 | 33.48 | 12.10 | 0.756

---------+---------+----------+-------+--------

The boiler had one defect, seen in the front view, cross-section. A

straight passage 2 inches wide was given to the gases between each pair

of tubes.

The boilers having all had a preliminary trial during the first week,

I observed the vapor arising from the exposed surface of the water in

the tank, and that this unmeasured loss of heat differed considerably

in the different boilers, and was enormously greatest on the trial of

the Allen boiler. I said nothing, but went down early on next Monday

morning and on my way bought a common tin cup about 3 inches deep and 4

inches in diameter, and secured it in one corner of the tank, immersed

to a quarter of an inch below its rim, and filled even full of water.

This was completed before the arrival of the Committee, and was at once

approved by them. I made it my business every day to note the fall

of the water level by evaporation from this cup. On the trial of the

Allen boiler only the water in the cup was all evaporated, and I had

to fill it again. The temperature of the water in the cup was always 8

degrees below that of the surrounding water. It was thus obvious that

the evaporation from the tank was greater than the fall of the level in

the cup would indicate. The Committee considered that this should be

increased as the tension of the vapors. The result was that the report

contained the following item: Units of heat carried away by evaporation

at the surface of the tank:

Root boiler 721,390.8 units

Allen boiler 1,178,404.5 „

Phleger boiler 378,371 „

Lowe boiler 692,055 „

Blanchard boiler 268,707 „

The same Bulkley pyrometer was used in all the furnaces to indicate the

temperature of the escaping gases. On Tuesday morning, when my boiler

was to be tried, I saw that before my arrival the pyrometer had been

set in the brick chimney, where the readings could be conveniently

taken by a person standing on the brick surface of the boiler chamber.

Its readings averaged 260 degrees Fahrenheit. I did not believe this

to be true. At about half-past two o’clock, when seven readings had

been taken, one each half hour, having got ready some bricks and mortar

and tools, I pulled the pyrometer out and filled up the hole. I then

knocked a hole in the side of the brickwork at the bottom, in front of

the flue, and set the pyrometer there. The reading rose to 405 degrees,

which was the temperature at which the gases then entered the flue,

and averaged about 385 degrees during the remainder of the sixteen

readings. Root’s average was 416 degrees, and Phleger’s (also tubular)

averaged 503. Obviously the readings taken before the pyrometer was

moved should have been rejected; but the boys who did this kind of work

added them all together, and our average temperature is printed 345.87

degrees, giving the boiler more credit than it was entitled to by about

40 degrees. I lost a little by this operation. While I was bricking up

the hole the fireman came around and told me I was spoiling his fire.

When I got the figures of water evaporated and coal burned, I found

that in that half hour I had only 900 pounds (three barrels) credited

to the boiler, instead of 1800 pounds (six barrels) during every other

half hour, being a loss of about .023 in water weighed in the barrel,

38,400 pounds, instead of 39,300 pounds, while, curiously enough, the

coal burned was rather increased.

The point of interest in this incident was the fact that the gases

had lost 125 degrees of heat in traversing a distance in flues and

chimney of less than 20 feet. This seems difficult to believe, but

they did. There was no leakage as the excellent draft clearly proved,

nor any other way of accounting for the discrepancy. The length of

the pyrometer tube exposed to the heated gases was the same in both

positions. The heat had been lost by radiation through the brickwork.

I have been waiting ever since for a chance to turn this knowledge to

useful account, but it has not come yet. I will content myself with

suggesting to somebody else the idea of facing the boiler setting,

flues and chimney, not only outside but inside also after leaving the

furnace, with white encaustic tiles, which will neither absorb nor

radiate heat appreciably. This will pay in maintaining the temperature

in a large degree to the top of the chimney, so increasing, perhaps

doubling, the strength of the draft. An enormous amount of heat must

be lost through the extended surface of the brick boiler setting. It is

always observed that the hotter a boiler-room is kept the greater the

efficiency of the boiler becomes. This is a slight indication of the

great gain which might be effected by the plan I propose.

Before this boiler trial we had lost Mr. Allen. He had conceived the

idea of the pneumatic riveter and the high-speed air-compressor to

furnish this riveter with power. In the latter he utilized the inertia

of the reciprocating parts, including two pistons, the steam and the

air piston. This he did with my cordial consent, and indeed there was

nothing patentable about that feature anyway. Mr. Allen thus became the

originator of the important system of pneumatic riveting, in its two

methods, by percussion and by pressure. Mr. Allen sold out his stock in

the engine company to Mr. Hope and Mr. Smith, and built a shop in Mott

Haven for the manufacture of the riveters and compressors. He took the

boiler in the fair in part payment, and sold it directly to a party who

had erected a wood-working shop at some point on the Harlem River.

The Croton water which had been fed to the boiler contained no lime,

but some sediment. Mr. Allen had the boiler taken down and brought

to our shop for inspection and cleaning. I determined to improve the

opportunity to observe the effect of the circulation on the deposit of

sediment, and the result of the examination proved most interesting.

Each inclined tube had been provided at the end with a brass plug, by

removing which it could be cleaned by the running out of the water

which it contained. This had not yet been done.

I took out the tubes on one side of one section, ten in all, five over

the furnace and five behind the bridge wall, and planed them in two

longitudinally, and had the following revelation: The tubes over the

furnace were entirely empty. In those back of the bridge wall a deposit

of sediment appeared, only about an inch deep in the first one, and

increasing regularly to a depth of 18 inches in the last one, which

was not the tube receiving the feed-water. So the water fed into the

last tube of each section deposited its sediment most largely in the

first tube it reached, in which the circulation was least active,

and had deposited it all before reaching the tubes over the furnace.

The remaining long tubes were then cleaned, the tubes cut in two were

replaced by new ones, and the boiler delivered to Mr. Allen. The next

stage in its history was very funny. The purchaser, to save the cost of

Croton water, fed his boiler from the Harlem River, and within a month

it was found to be filled solid with salt. What was done about it I

never heard.

I thought I could sell the boilers where, as in New York City, they

could be fed with water free from lime, and I made a few such sales,

but the inspiration which led me to employ the second drum for

superheating the steam had deserted me.

I came to the conclusion that by making the first drum a large one,

and not extending the nipples into the drum to trap a puddle of water,

as I had done, I could superheat the steam in one drum. That was a

blunder. I had underestimated the furious circulation, which carried a

large amount of spray into the drum. I was misled by the quiet position

of the water-level, as always shown in the glass gauge. Instead of

superheated steam, I found the boiler to give very wet steam. That

fault, of course, I could have remedied by returning to my first

design. But I was discouraged by other things. The first, of course,

was the impossibility of removing scale by any mechanical means. The

most serious discouragement was a cracked header. The inclined tubes,

on any plan for their use that I could then design, made cast-iron

headers necessary. I had taken great pains to obtain perfect castings,

making them of the best iron in baked molds in iron flasks, of uniform

thickness, ⁵⁄₈ in., and ³⁄₄ in. where threaded, with cores held

perfectly central and remarkably well vented, and felt that I could

rely on their soundness; but this defect showed that I could not. So

reluctantly I abandoned the manufacture of the boiler.

I believe, however, that there is yet a future for the inclined boiler

tube, with independent circulation in each tube, the whole made

entirely from forged steel; and that better results will be obtained

from it than any other form of boiler has as yet given. I have been

told by Chief Engineer Melville that all water admitted to the boilers

in the United States Navy is made pure enough for pharmaceutical

purposes. If this can be done in the navy, where sea water and the

mud of harbors have to be used, it can be done anywhere. Cooling

towers make it practicable to return all water to the boiler even from

non-condensing engines. Then only the waste needs to be made good, and

any water can be purified for this purpose. Oil or grease with the

feed-water is readily avoided. Only electrolysis remains to be provided

against, which can be done by avoiding the use of any alloy of copper

in contact with the water. We may then have boilers of the most durable

character and safe to carry any desired pressure.

The following incident near the close of my experience in Harlem

would be too ridiculous to print except for its consequence. One day

Mr. Smith sent me word that he would like to see me in his office.

When I entered he asked me, “What do you pay for the castings of your

governor arms and balls?” Of course he knew perfectly well, as he

had the bills and the books, but that was his way of introducing the

subject. I replied, “Forty cents a pound.” He held up both hands in

affected amazement, and exclaimed, “Forty cents a pound! Well, sir, I

can assure you of one thing, no more of this company’s money is going

to be squandered in that way.” I overlooked his insulting language and

manner, and said quietly, “Are you sure, Mr. Smith, that you have all

the information you need to form a correct judgment in this matter?” “I

am sure,” he replied, “what the market price is of copper and tin, and

that I can get castings made from our own metal at a price that will

bring the cost to not more than 25 cents a pound.”

“This, then, I presume, is all you know about the subject,” I said,

“and you ought to know a great deal more, which I will tell you. It is

necessary that I can rely upon getting a pure copper and tin alloy,

in the proportion known as gun-metal, on account of its strength,

its rigidity, and its wearing qualities. The latter is of especial

importance, because the governor joints are in continual motion under

the weight of the heavy counterpoise. Experience shows that this purity

cannot be relied upon where it is possible that any inferior metal can

become mixed with this alloy in even the smallest proportion. This for

us, not making our own castings, must be wholly a matter of confidence.

“Another risk must be avoided, that is, of getting bad castings. The

castings must not have the least imperfection. The time lost, through

finding defects that make it necessary to reject arms after more or

less work has been put on them, would soon wipe out all the little gain

you look for; as these castings, at 40 cents a pound, only cost about

five dollars a set, as an average of all the sizes.

“I made a careful study of this subject when I commenced the governor

manufacture about fifteen years ago, and found David Francis, who

had a small gun-metal foundry on Vestry Street, to be just the man I

wanted. No inferior metal ever goes into his place. He enjoyed the

entire confidence of manufacturers. He has made my governor arms and

balls ever since. I have never had a bad casting from him, and always

got the pure metal, and have paid him the same price that everybody

pays him for small castings. I consider the security that I have had

respecting this metal to have been fundamental to the great success of

my governors, and that I would be crazy to make any such change as you

propose.”

He made no reply, and I left him, supposing my statement to have been

perfectly satisfactory. What was my amazement when, a few days after,

he informed me that he had made a contract with a brass molder on Rose

Street for casting our governor arms, “subject to your approval, sir,”

and he asked me to visit the place and see what its facilities were.

I told him I would go, but that my position on the subject was already

well known to him. I found the place on a little lane, and that the

business done in it was making brass castings for plumbers. The

proprietor told me he had never made gun-metal castings, but he could

make any kind of composition, and I could rely on getting them of just

the metal I furnished him.

I reported to Mr. Smith that such an arrangement would be ruinous, that

his plan of furnishing the metal was most unbusinesslike. “What do you

know about business?” he shouted with a sneer. “I know,” said I, “that

if you should propose this plan to any well-informed, practical man,

he would laugh in your face, and tell you if you wanted to ruin your

business this would be as good a way as any to do it.” He replied,

“That is not the question, sir; the only question is, will you, or will

you not, approve the contract I have made?” “I will not,” I replied,

and walked out of his office.

A few days after I received a note from Mr. Hope, asking me to call

on him. I called next day, and he told me that Mr. Smith had been to

see him, with a bitter complaint of my insubordination and defiance of

his authority, which he would not endure, and he asked me to tell him

what the trouble was about. I told him substantially as above related.

“Is that all?” said he. I assured him that it was all the trouble that

I knew of. Mr. Hope replied, “I cannot express my amazement at his

interference with your management. That must be absolutely entrusted

to you, and he ought to see it. He is a rational man and I can easily

show him his error, and that you _must_ take the stand you have done. I

don’t think you will have any more trouble.”

I did not hear again from Mr. Hope for a fortnight, during which time

I had no occasion to meet Mr. Smith. Finally a letter came from him,

telling me that I must prepare for the worst; he had exhausted all his

efforts on Mr. Smith, and found him absolutely immovable, declaring

that I must go, I was of no use there, anyway. Mr. Hope said he told

him his conduct was outrageous and suicidal. If I went, that I would be

the end of the business. He snapped his fingers at that, saying, “Mr.

Goodfellow can make the engines, and I can sell them; what more do you

want?” He declared that no business could succeed unless the will of

the president was law. They had several very disagreeable conferences,

which Mr. Smith always closed by saying, “Repay me my investment in

this company,” which he figured at $24,000, “and I’ll give you my

stock.” He had announced to Mr. Hope his determination to call a

meeting of the directors to discharge me, and as he had a majority of

votes, having some time before given to each of his two sons qualifying

shares and had them elected members of the board of directors, he held

the power in his hands to do it.

Directly after, I received a copy of a notice of a regular meeting of

the board, convened strictly according to law. I could see no ray of

light. The night before the meeting I walked the Third Avenue bridge

half the night. The meeting was called to order by Mr. Smith at the

appointed hour. Mr. Hope was absent. Mr. Smith said Mr. Hope had sent

word to him the day before that he might be detained, but if so would

come up on the next boat, which ran hourly, and asked Mr. Smith to wait

that time for him.

So the meeting was adjourned for an hour, when Mr. Hope arrived.

Mr. Smith prefaced the resolutions discharging me from my position as

superintendent and electing Mr. Goodfellow in my place, by quite an

oration, setting forth the solemn sense of his Christian duty which

left him no alternative, and the necessity of proper subordination in

any business, if it was to be successful, and the especially aggravated

character of my offense, and the demoralizing nature of my example.

He was about to put the question on the adoption of the resolutions,

when Mr. Hope said, “Before you put this question to vote, Mr. Smith, I

would like to say a word. I have concluded to accept your offer. Here

is my certified check for $24,000 to your order, and I demand from you

the transfer to me of the stock in this company standing in your name

and the names of your sons.”

When the Smiths were gone (they left by the next boat) Mr. Hope and I

sat down to confer on the business of the company. When these matters

were concluded, I said to him, “Mr. Hope, if you had determined to make

this grand proof of your confidence in the engine and in myself, why

did you not tell me sooner, and save my wife and myself a great deal of

distress?”

“My dear fellow,” he replied, “I did not know till this morning that I

should be able to do it. That is why I was late.”

Engineering reminiscences contributed to "Power" and "American machinist" · 第 19 / 28 章