perience will show, however, that, if the
habitual pull is right for a perfect calm,
the slightest wind will carry out the cen-
ter of the tape to fully one-half a foot
sag, without being sufficient to suggest
the necessity for increasing the pull in
order to reduce the sag.
A second reason why surveyors do not
measure horizontal distances is that the
ends of the tape are not kept level. If
a man says '* I can do it," watch him
closely, for when he succeeds it will be a
mistake. If he says " I can come pretty
near it," give him credit for understand-
ing the situation and watch him too.
There is a difference of ability to judge,
but at some point every person would
recognize such an error. In this case we
have the joint judgment of at least two
men presumably somewhat experienced.
The limit of their error will be approx-
imately uniform for like conditions ; prob-
ably will not exceed two per cent, of the
length of the tape. We may suppose
that no error in judging the level exceeds
two per cent., and assuming a probable
distribution of errors within that limit
calculate the probable correction, but the
result is too small to account for the
facts. A surveyor of any experience
knows that somehow or other this cor-
rection must sometimes amount to con-
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ELIMINATION OF ERRORS IiV FIELD WORK.
113
siderable. On lines where appearances
are deceiving, it is customary, when there
is a difference of opinion, to test the mat-
ter by plumbing a different height, and
correcting the pin, if an error is apparent
Now this method of correction is not ap-
plicable to errors of inclination, which
are smaller than two per cent, and some
which are larger than that will slip
through. On some lines this check is
necessary every time for a large part of
the distance. On such lines the head is
no longer level ; the apparent horizontal
differs from the truth, and the probable
range of error instead of being equally
each side of the horizontal, is all one
side, and may be at its limit nearly five
per cent. The part exceeding two per
cent, may be very nearly all ehminated
by the method noted above. I conclude
that there is alioays an error due to the
fact that the tape is not horizontal, and
this is always a minus error. A constant
correction for it and for the resultant be-
tween sag and pull should* be determined
by the surveyor for his " team," and ap-
phed to sticking of the pin. A further
minus correction is due this cause on
difficult lines, before it should be called a
mistake ; at its extreme limit I place it at
two-tenths of a foot in one thousand feet
— the correction due to an inclination of
two per cent. This further correction
should never be applied to graded lines,
for there such an error is inexcusable.
"Were it not for variations due to
temperature," Mr. Culley says, "All Hues,
both long and short, within the scope of
the land surveyor, could be measured ex-
actly." The idea of dating a survey in
order to be able to judge of the probable
error due to this cause, which he suggests
farther on, may do in Cleveland ; but in
a climate which boasts of 80° F. in Jan-
uary, and 60° F. in July, with a wide
range of temperature in any month, this
method of eliminating the error is falla-
cious. The plus and minus maximum
errors due to this cause are very large ;
but the easiest in the whole list to man-
age. I attach a thermometer to my
transit so as to carry it conveniently, ob-
serve the temperature in the sun or in
the shade, according to the average con-
dition of the line, and make the correc-
tion then and there.
The standards furnished by the Gov-
ernment are rods of steel correct at 60°
F., or as marked. Using these, a rod of
steel as long as the tape used should be
marked with the standard length at 60°
F. This standard, for obvious reasons,
should be sheltered from the sun, wind
and rain. If an office floor is long
enough, it will furnish a convenient place
for fixing it. The center should be held
firmly, and the ends be so fastened that
they may expand freely, but cannot be
bent or sprung out of place. The mark-
ing should be done after it is in place.
A tape tested on such a standard is cor-
rect at 60° F., whatever may be the tem-
perature when the test takes place, pro-
vided that the tape be brought to the
same temperature as the rod before the
test is made. All measurements should
be made with the tape at its tested length,
and the correction applied to the whole
distance measured. Some tapes are
made so as to apply the correction to the
tape. I have tried both ways, and don't
want any adjustable tape in my work.
A thermometer is equally necessary, and
one more loose end is to be watched with
no corresponding advantage.
I have found this table useful on a fly
leaf of my field book :
"S -
100'
200'
800'
400'
600'
600'
700'
800'
900'
Feet.
Feet.
Feet.
Feet.
Feet.
Feet.
Feet.
Feet.
Feet.
0.042
0.084
0.126
0.168
0.210
0.262
0.294
0.336
.378
10
.035
.070
.105
.140
.175
.210
.245
.280
.315
20
.028
.066
.084
.112
.140
.168
.196
.224
.252
80
.021
.042
.063
.084
.105
.126
.147
.168
.189
40
.014
.028
.042
.056
.070
.084
.098
.112
.126 .
50
.007
.014
.021
.028
•-
.085
.042
.049
.066
.068
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114
VAN nostrand's engineering magazine.
-f-EBB0B8.
70
.007
.014
.021
.028
.085
.042
.049
.056
.068
80
.014
.028
.042
.056
.070
.084
.098
.112
.126
90
.021
.042
.068
.084
.105
.126
.147
.168
.189
100
.028
.056
.084
.112
.140
.168
.196
.224
.252
110
.035
.070
.105
.140
.175
.210
.245
.280
.815
120
.042
.084
.126
.168
.210
.252
.294
.336
.378
There is nothing new in it, but it is
better to do a simple thing right once for
all than to be doing it over and over
again for all time.
The force of the wind upsets aU these
calculations. Our catenary curve that
was a function of a; and y is now a func-
tion of Xj y and z. The plumb ceases to
point to the center of the earth. Its
average position is misleading — is the re-
sult of a composition of forces. These
effects can be mitigated to some extent
by holding the center of the tape to its
place in Ime, by shielding the plumb and
increasing the pull; but such work is
always unsatisfactory. The only way to
eliminate this source of manifold errors
is to cease from any piece of work when
the wind is so high that it cannot be
done as it should be done. There are
estimates, topography, etc., which do not
require a high degree of precision and
can be done when other work cannot.
Subdivision work, where it is proposed
to to build brick walls to property lines,
showing errors in closing or subdivision
of 1 in 6,000, should doubtless be re-
traced. The average en*or of re-surveys,
built on such a basis, need not exceed
1 in 20,000. -The maximum error can
then be kept within manageable limits.
SOME POINTS ABOUT MODERN WAR SHIPS
Bt LIEUT. B. A FISKB, U.S.N.
Th£ best rough measure of the value
of a modem war ship is the weight of
water she displaces, for this equals the
weight of the ship and her contents, and
the greater it is the larger her hull can
be, the thicker her armor, the more pow-
erful her engines, the heavier her guns,
and the greater her coal and ammunition
capacity.
A perfect war ship would be one able
to resist any projectile or torpedo and to
pierce any armor made, and at the same
time to throw a greater weight of metal
per minute, to turn more rapidly, and to
steam faster and further than any other.
Ability to resist any projectile or tor-
pedo would necessitate great thickness
of armor and a heavy inner bottom ; abil-
ity to pierce any armor would require
very large guns ; ability to throw a great-
er weight of metal per minute thaja any
foreign war ship would render necessary
a considerable number of guns, and these
would require a considerable space to be
protected, which means a considerable
extent of armor.
We can see at a glance that the weight
of guns and armor alone would be enor-
mous, and that, in consequence, the ship
would be immense, since she must be,
not only as large as a volume of water of
equal weight, but larger, in order that
she may possess sufficient reserve buoy-
ancy to doat her when a sea comes on
board, or when a water-tight compart-
ment fills after a torpedo explosion or a
collision. But the ship must be large
enough to float, in addition, her machin-
ery and coal, and these would be very
heavy, since the boilers and engines must
be very powerful in order to secure the
necessary speed, and must have an enor-
mous supply of coal at hand in order to
steam the necessary distance.
Clearly, a perfect war ship would be
an exceedingly ^heavy and expensive one.
An English naval architect in a recent
lect^e before the Royal Naval College,
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NEliLEOTED DUTIES OF THE ENGINEER.
115
stated that a war ship, to be even approx-
imately perfect, womd weigh about 25,-
000 tons, and cost, at least, £2,000,000!
Since perfection cannot, at any prac-
ticable cost, be attained in any one war
ship, the only thing to do is to design a
number for different purposes, seeking
in each certain excellencies, and resign-
ing others. In a heavily armored ship,
in which power of offence and defence
must be very great, the weight allowed
must be expended principally in guns
and armor, so that great speed and coal
endurance have to be abandoned. In a
•cruiser, on the other hand, speed and
coal endurance are essential, so that ar-
mor and heavy guns must be resigned ;
while in a gunboat heavy guns and great
speed must be secured, and armor and
coal endurance sacrificed.
Furthermore, speed is comparatively
an easy thing to get in a ship, if we are
at liberty to make her as long, as narrow,
and as deep as we please, and to place
the boilers, engines and steam-pipes in
•convenient positions. But a long ship
will not turn so quickly as a shorter one,
jet handiness is almost as important in a
war ship as speed ; a long ship cannot
have so thick armor as a shorter one car-
rying an equal weight of armor, and she
is easier to hit. To make a war ship
deep forces on her the naval disadvantage
of great draught, which prevents her
from entering some harbors and from
chasing vessels near some coasts; and
boilers, engines and steam-pipes have to
be crowded below the water line to pro-
tect them from projectiles. Is it a mat-
ter for wonder, then, that war ships are
not so fast as some passenger steamers
whose requirements are so simple !
It is sometimes urged that war ships
should carry a great deal of sail, in order
to be able to stay a long time at sea with-
out gomg into port for coal. But masts
and spars are very heavy ; they fall on
deck when struck in action, and kill men,
and they present such resistance to the
air that they decrease the speed when a
ship is fighting under steam alone — which
is the oi^y way in which a ship can fight.
Moreover, if a war ship should be caught
under sail by a hostile war ship under
steam alone, she would simply be in the
position of a ship unprepared meeting a
ship thoroughly prepared to fight; and
while she had her men aloft furling sail
and '* clearing ship for action," the other
could be knocking holes in her hull with
heavyy guns, and killing the men aloft
with Hotchkiss and Q^tling machine
guns.
SOME OFTEN NEGLECTED DUTIES OF THE ENGINEER.
Bt FRANCIS COLLINGWOOD, Am. 800. C. E.
An Address before the Alumni of Rensselaer Polyteohnio Institute.
Im a recent address before the Institu-
tion of Mining Engineers, the subject of
ethics, as bearing upon engineering prac-
tice, was treated with some fullness by
the retiring president, Mr. Baylis. It is
not my intention to repeat what he has
so well said, or to take up the more ob-
vious duties which are so often brought
forward in addresses at the commence-
ment season. Such addresses usually
tre^t of those qualities which form the
foundation of the character of every
really successful engineer, and more
especially of the necessity for that abso-
lute honesty of purpose in every rela-
tion he holds, whether as designer, as
supervisor, or as arbitrator, which alone
can lead to the thoroughness of work,
and which at once places him on his
guard against any cGshonest approach,
however it may be disguised. Out of
this one requirement spring all the ordi-
nary duties of the profession ; but pass-
ing these by we come to others more
recondite, growing out of the relations
of the engineer to the profession and to
the world of science, and which seem
more appropriate for consideration in ad-
dressing a society among whose mem-
bers are men of large professional expe-
rience. These latter duties are none the
less important, but in the hurry of active
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VAN NOSTRA.ND'8 ENGINEERING MAGAZINE.
life, they are too often overlooked or but
imperfectly performed, and since every
dereliction of duty is sure to react to our
detriment, it the part of wisdom to guard
watchfully against such in every direc-
tion.
Entering, then, upon our subject, and
proceeding from the lesser to the greater,
let us consider first the relations of the
chief engineer of an important work to
the members of his staff. As a matter of
course he expects absolute loyalty on the
part of all those under him, and any dis-
loyalty would probably end in the prompt
dismissal of the offender. How shall such
loyalty be obtained ? Shall it be the re-
sult of fear, or shall it be bred of mu-
tual regard and confidence ? In other
words, is the duty all on the part of the
subordinate, or is there a reciprocal ob-
ligation implied on the part of the chief 1
If the latter question be affirmatively an-
swered, as it must be, let us proceed to
state clearly what the obligation is. Here
we should remember that the most emi-
nent engineers have all been subordi-
nates, and have had the help of others
by which to rise. As an inevitable co-
rollary upon this, it follows that the
chief owes it to all in his employ to help
them freely in their difficulties, and to
be readily approachable. By thus doing
he will make them stronger men profes-
sionally and help forward his own suc-
cess. Our first duty, then, may be de-
fined as that of politeness, affabiUty, and
a personal regard for subordinates. Mr.
H. H. Kichardson, of Boston the well-
known architect, recently deceased, fur-
nished a prominent example of one who
nobly fulfilled this duty. In a notice of
his life work, the Sanitary Engineer
writes as follows :
" Nor less delightful than this office in
the country was Mr. Kichardson's rela-
tion to the draughtsmen he employed.
Only those who have had the privilege of
working under him can have much idea
of the generous interest he took in their
welfare and artistic progress, encourag-
ing them and advising them in their
studies, and ever ready to listen to in-
telligent suggestions, treating his men as
personal friends rather than employes.
Often he would invite a number of his
older pupils to evening reunions, where
he would talk over with them matters re-
lating to their art. His valuable library
and collection of photographs was always
accessible to his draughtsmen, and he
encouraged their constant reference to
them. Few men have such power as he
had of filling others with his own en-
thusiasm."
There is a second way in which the
chief can help those under him, but to
which selfishness often blinds his eyes.
It frequently happens in the progress
of a work that the one coming in imme-
diate contact with some of the many
problems involved will bring out a solu-
tion or work up a design having real
merit. The credit for such design does
not belong to the chief, and, as a matter
of simple justice, he should, in making
up his reports, give full credit to the de-
signer; yet, in many cases this is not
done at all, and the assistant, is men-
tioned in merely general terms and with
no reference to his special work. This
is not the way to obtain whole-hearted
service ; a chief engineer can akoaya af-
ford to be generous to his helpers. A
full acknowledgment of all good work,
no matter by whom done, in nowise de-
tracts from his own standing; on the
contrary, the world will think the better
of him for it. The work is always known
afterwards as that of the chief, and if he
adds generosity to his other qualities,
he will but stand the higher in the esti-
mation of all thinking men. It is said
that one great reason for the popularity
of General Grant was, his generous treat-
ment of all those under him.
There is yet another duty of the chief
which has much to do with a hearty,
loyal helpfulness on the part of subordi-
nates. In the inception and progress of
a work, it is he who in a great measure
determines the respective salaries to be
paid to the other members of his staff.
The vicious doctrine that no more will
be paid than the market will command,
with no regard for the cost of living or
for the character of the services rendered,
too often prevails, and many men seem
to think that if they are insured a good
salary, it is laudable to cut the salaries of
all below them down to the lowest at-
tainable limit. It is only necessary to
carry this doctrine to its ultimate con-
clusion to prove that it is both unjust
and unwise. If we want a horse to do
his fullest work we do not begin by scant-
ing him in his food, but we give him full
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provender and the best of care. Are
men so different that we can expect them
to do their best when they are but half
paid for their labors! Is there not sure
to be in their minds a rankling sense of
injustice? If an assistant so paid be
too honest to slight his work, he will still
be preoccuppied by thoughts of '*how
to make both ends meet'' in his expenses,
or how to be able to meet just debts,
possibly those incurred in obtaining the
education which has fitted him for the
very thing he is doing, and, as we all
know, a preoccupied mind is not fitted
for deep or consecutive thought on any
subject. The chief should therefore in-
sist at the outset upon full compensation
for all services rendered, and should be
the first to recognize good and faithful
work, by asking for such increase in sal-
ary as may be consistent with its value.
A man who lets neither time, study,
labor, nor expense interfere with his at-
tention to his duties, is certainly worth
more than one who works always by the
clock (trades unions to the contrary, not-
withstanding) ; and a worthy man should
not be obliged to ask for that which is
rightly his due.
In immediate connection with the sub-
ject of organization of a staff arises that
of a proper recognition of the relative
position of subordinates; by this is
meant the military idea that orders shall
be issued and reports received always
through those next in rank, and not, as
is too often done, with an entire disre-
gard of precedence or system. An engi-
neer has a right to suppose that each one
in his place is attending to his duties,
and to pass over the one next below him
and give an order to a minor, implies a
lack of confidence in the first, is likely to
cause insubordination in the second, and
is sure, eventually, to introduce confu-
sion and ill-feeling in the staff. Having
placed a man in position he should be
held stricty accountable for all work en-
trusted to him, and if found unfaithful
he should be removed ; but to pass him
by and ignore him, whether by attempt-
ing to do the work personally, or by as-
signing it to others, is an evidence of
weakness, and is doing one wrong to
mend another.
Such abuse of good management is,
however, often committed where no fault
is attributed, in which case it shows a
lack of sound ideas as to administrative
methods, and is still to be unqualifiedly
condemned. Not only does it introduce
discord into the sei*vice, but in just so
far as a man misdirects the labors of
those under him and relieves them of
tJieir due share of responsibility, does he
injure his own efficiency and make his
own labors heavier. Here it may not
be amiss to quote with proper reserva-
tion the advice that has been given engi-
neers to "never do yourself what you
can get others to do for you.'* In a re-
cent obituary notice of a prominent Eng-
lish engineer the following sentence ap-
propriate to the case in point occurs :
*' The confidence reposed by Mr. Leather
in his staff, and the freedom with which
its members were thus enabled to grap-
ple with the many sudden emergencies
inseparable from sea-works, were also
important factors of his success in these
undertakings."
It not unfrequently happens that
boards of direction and other employers
show a lack of this confidence 4n their
chief engineer, and are guilty of the
gross impropriety of attempting to give
personal directions to assistants, or of
receiving reports from them.
The practice cannot be too strongly
reprehended. It is an axiom in physics
that two bodies cannot occupy the same
place at the same time, and it is no less
true that two persons cannot attend to
one and the same set of duties at once.
Confusion is inevitable. ** Dual control"
is bound to be a failure wherever under-
taken:
The subject of reciprocity of duties be-
tween the employer and employed (or,
as a special case, between the engineer
and his assistants) is one that is assum-
ing greater prominence now than ever
before in the world's history. Men are
slowly learning that the rule of selfish-
ness is inevitably and always misrule, and
that in the complex relationships of our
modern civilization, a wrong done to one
class is bound in some way to react on
all other classes. Heretofore the wealthy
and powerful have been the oppressors,
but now the laboring man has learn eel
the lesson so well that he takes delight
in enteiing into a worse bondage, in or-
der that, by the might of numbers, he
may inflict loss on those whom he con-
ceives to be his enemies. It is evident
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VAN N08TRAND 8 ENGINEERING MAGAZINE.
that peace and industrial faarmony can be
again established only on the higher
principles of confidence, co-operation,
mutual helpfulness, and good will ; in
other words, on the golden rule of doing
as you would be done by. As has been
recently so eloquently said by Bishop
Potter : '* When capitalists and employ-
ers of labor have forever dismissed the
fallacy, which may be true enough in the
domain of political economy, but is es-
sentially false in the domain of religion,
that labor and the laborer are alike a
commodity, to be bought and sold, em
ployed or dismissed, paid or underpaid,
as the market shall decree ; when the in-
terest of workman and master shall have
been owned by both as one, and the share
of the laboring man shall be something
more than a mere wage ; when the prin-
ciple of joint interest in what is pro-
duced of all the brains and hands that
go to produce it is wisely and generous-
ly recognized ; when the well-being of
our fellow men, their homes and food,
their pleasures, and their higher moral
and spiritual necessities, shall be seen to
be matters concerning which we may
not dare to say, *Am I my brother's
keeper ? ' then, but not till then, may we
hope those grave social divisions concern-
ing which there need be among us all, as
with Israel of old, * great searchings of
heart,' " may cease. But let us return
from this episode.
We have thus far discussed what
might be called the family relationships
of the engineer, and more particularly
those readiing downward, the duty of
each man to lend a helping hand to all
below him on a work, thus insuring the
highest efficiency of the staflEi and doing
incidentally a still better thing, helping
all to be stronger and more useful men.
There is, however, a larger company, of
which every engineer forms an integral
part and to which he owes certain duties
— viz., the profession as a whole; and to
this I would next direct your attention.