occupied a large share of Ericsson's attention, and in particular was
this the case in connection with his naval designs. From the
"Princeton," in 1841, to the "Destroyer," in 1878, there succeeded one
long series of types and forms of steam-engine, each in his opinion the
best adapted to the circumstances of the case. Naturally, opinions
differ, and he was brought into competition with other able engineers,
and his designs were often called into question or subjected to
criticism. In 1863, in competition with Chief Engineer Isherwood of the
navy, engines were designed for twin ships, the "Madawaska," afterward
known as the "Tennessee," and the "Wampanoag," afterward called the
"Florida." This was a battle royal of types and modes of application of
the power of the steam-engine to the propulsion of ships. The result was
a victory for Isherwood, although the "Madawaska," which was first
subjected to trial, made a speed higher than any warship at that time
afloat. This was exceeded by the "Wampanoag" a short time later; but
neither engine was of an enduring type, and after a time the machinery
of the "Madawaska" was removed, and she was repowered with a later type
of machinery, and long did service as the "Tennessee" in the list of
wooden frigates of the navy. The "Florida" was too expensive to maintain
in commission, and the special circumstances which had called her into
existence having passed by, she was laid up at New London, and never
again saw active service.
Keenly as Ericsson was interested in the steam-engine, it must be
admitted that he always showed a more profound interest in some form of
engine which should be able to displace it with a superior efficiency;
and hence his long series of efforts relating to the flame-engine, the
caloric engine, the gas-engine, and finally the solar engine,--with
either steam or heated air as the medium for carrying the heat. During
the last years of his life some of his most patient and careful study
was given to the perfection of a solar engine, or engine for utilizing
directly the heat of the sun instead of that of coal or other carbon
compounds. Besides this direct line of study and experimentation, he
gave during these years much thought to various scientific problems
connected with solar energy, the tides, gravitation, the nature of heat,
etc., etc. A plan for deriving power direct from the tides, improvements
in high-speed engines for electric-lighting purposes, further
improvements in his hot-air engine in small sizes for commercial
purposes,--these are some of the further lines of work which occupied
the attention of his closing years.
But the most cunningly devised of all mechanisms, the heart and brain,
must sooner or later tire and cease from their labors. The motive energy
becomes exhausted, and the mechanism must cease its work. So it was with
John Ericsson. In the first hour of the morning of March 8, 1889,
Ericsson died. This was within one day of the twenty-seventh anniversary
of the battle at Hampton Roads, the event with which the name of
Ericsson will always be associated, and which has given to it a
significance that will never be forgotten. His remains were first
interred in New York, and then, in 1890, in accordance with the request
of the Swedish Government, they were returned with impressive services
to his native land, where they now rest. In his death he received his
highest honors, for his remains were conveyed across the Atlantic by the
U.S.S. "Baltimore," one of the new ships of the navy specially detailed
for that service, and on both sides, in the United States and in Sweden,
the event was marked with every honor and ceremony which could indicate
the significance of his life and services for his adopted land and for
the world at large.
The two pieces of work which perhaps will be most permanently linked
with the name of Ericsson are the screw-propeller as a means of marine
propulsion, and the "Monitor" as a type of warship. In addition to
these, however, his life-work was rich in results which bore direct
relation to many other improvements in the broad field of marine
engineering and naval architecture. Of these a few of the more important
may be mentioned, such as the surface condenser, distiller, and
evaporator, forced draft for combustion, placing machinery of warships
below the water-line, and their protection by coal, ventilation by
fan-blowers, together with a vast variety of items involved in the
conception and design of the "Monitor" as a whole, and in his other
naval designs.
In order to appreciate the influence of Ericsson's life and work on the
field of marine construction, a brief glance may profitably be taken at
this branch of engineering work as it was before Ericsson's time, and as
it is now.
The material employed for shipbuilding was almost entirely wood. This
was displaced in the 'sixties and 'seventies by iron, which in turn was
displaced by steel, so that at the present time, except for special
reason, no material other than steel is thought of for this purpose.
With the gradual displacement of wood by iron in the mercantile marine,
Ericsson's relation was only indirect. Some of the earlier mercantile
vessels in which he was interested were of wood and some of iron. In the
field of warship construction, however, his influence through the
"Monitor" was more direct, especially as to the value of metal armor as
a protection against great gun-fire. Still, it is no more than justice
to say that with the change from wood to iron which took place during
the active part of his life, Ericsson had only an indirect relation, and
the change would doubtless have come about at the same time, and in much
the same general way as it did, independent of any influence which his
work may have had upon the question. Turning to the means of propulsion,
we find sails as the main, or almost only, reliance during the early
years of the century. The steam-engine operating paddle-wheels had come
to be recognized as a possibility, and under certain conditions as a
commercial success. The screw-propeller as a means of propulsion was
known only as a freak idea, and was without status or recognition as a
commercial or practical means for propelling ships. So far as the
screw-propeller was thought of as a means of propulsion, it lay under a
suspicion of loss of efficiency due to the oblique nature of its action,
and this was supposed to be such as to render it necessarily and
essentially less efficient than the paddle-wheel.
Ericsson lived to see the use of sails almost entirely discarded for war
purposes, and for mercantile purposes relegated to ships for special
service and of continually decreasing importance. He lived to see the
steam-engine take its place as the only means for supplying the power
required to propel warships, and attain a position of almost equal
relative importance in the mercantile marine. He lived to see the
paddle-wheel grow in importance and estimation as a means of propulsion
only in turn to be supplanted by the screw-propeller, which gradually
increased in engineering favor from the days of its obscure infancy
until it became the only means employed for the propulsion of ships
navigating the high seas, while it had become a most serious rival to
the paddle-wheel even for the purposes of interior and shallow-water
navigation,--long a field considered as peculiarly suited to the
paddle-wheel and to the engines adapted to its operation.
Regarding the change from wind to steam for the motive-power of ships,
Ericsson did his full share among the engineers of his day, but it would
be unfair to many others to claim for him any exclusive or
preponderating influence in this movement, and in such matters it is
difficult to clearly define the services of any one man. The lines of
progress, however, have been in accord with his studies, and his work
has certainly had a most direct and powerful influence upon the
movement. The most important points of contact between Ericsson's work
and these advances were in connection with his introduction of the
surface condenser, the use of artificial draft, devices for heating feed
water, his studies in superheated steam and its use, and his work in
connection with the development of the compound principle in
steam-engines, his relation to the introduction of the screw-propeller,
and to the use of twin screws at a later time. He also devised and
adapted many new types of engines for marine purposes, having respect to
the geometrical character of the connections by means of which a
reciprocating motion of the piston may be transformed into a rotary
motion of the shaft. In particular, he was the first to introduce and
show the advantages of engines directly connected to the
propeller-shaft, instead of through the more indirect and clumsy modes
which others had previously thought necessary.
Aside from his relation to the screw-propeller, perhaps no item of his
work in connection with the steam-engine is of more importance than the
surface condenser, with its variant forms in the distiller and
evaporator. If Ericsson had done nothing else, his claims to recognition
and remembrance as an engineer and benefactor might have been well
founded on his work in this connection. As it is, the fact that he was
so largely instrumental in their perfection and adaptation to marine
uses is wellnigh forgotten in the brighter light of his other
achievements.
Regarding Ericsson's relation to the successful introduction of the
screw-propeller, little need be added to what has already been said.
Whatever may be urged regarding dates and patents or earlier years in
which the screw-propeller was used, it is a fact that in 1833-35 it was
not recognized as an accepted mode of propulsion. While known as a
possibility, it had no standing in the engineering practice of the day.
A few years later it was recognized as an accepted mode of propulsion
and had gained a permanent and definite place in the practice of the
day,--a place which has continued to grow in importance until its
earlier rival, the paddle-wheel, is almost on the brink of relegation to
museums of antiquities, except possibly for rare and special
shallow-water uses. A careful and dispassionate study of the facts, so
far as they can be known at the present time, seems to indicate clearly
that of those who were concerned in successfully adapting the
screw-propeller to the needs of marine propulsion and in laying the
foundation for these changed conditions, especially in the United
States, none was so prominent as Ericsson, or so fairly deserving of the
chief credit; and with this judgment the mature thought of the present
day seems to agree with little dissent.
Turning to a consideration from a similar point of view of Ericsson's
services in connection with warship design and construction, note may be
first taken of the condition of the art of naval warfare in the years
1840-50, or when Ericsson first began his labors in this field.
The material used was wood, the means of propulsion sails, with some
thought of steam-engines and paddle-wheels; the means of offence were
cast-iron guns large in number but small in size, the largest being 9 or
11 inches in diameter and throwing a shell of some 75 or 130 pounds
weight, while the means of defence consisted solely in the "wooden
walls," and modern ideas regarding armor had not even appeared above
the horizon.
Ericsson's contributions to the art of naval warfare are embodied in the
"Princeton," the "Monitor" and its class, and the "Destroyer." In the
"Princeton" the material used was wood, and in the "Monitor" and
"Destroyer" iron, following simply the developments of the age. In the
three the means of propulsion was by screw-propeller. In the "Princeton"
the means of offence were two 12-inch wrought-iron guns, as already
noted. In the "Monitor" and its type the means of offence were two
11-inch smooth-bore cast-iron guns, followed later by larger guns of 13
and 15 inches of similar type. In the double-turreted monitors four such
guns were of course installed. In the "Destroyer" the means of offence
was a single gun for discharging a torpedo under water at the bow. On
the "Princeton" the means of defence consisted still in wooden walls,
while in the "Monitor" and its class the change was profound and
complete. The essential idea of the "Monitor" was low freeboard and
thus small exposed surface to the ship herself, combined with the
mounting of guns in circular revolving turrets, thus giving an
all-around fire and on the whole making possible an adequate protection
of the exposed parts of the ship and providing for the combination in
maximum proportions of armored protection and heavy guns for offence. On
the "Destroyer" the means of defence consisted simply in a light
deflecting deck armor forward, the vessel being intended to fight bows
on and depending on her means of offence rather than defence, which were
made quite secondary in character.
The "Monitor," however, was Ericsson's great contribution to the art of
naval war, and with it his name will always be associated. It broke with
the past in every way. It reduced the number of guns from many to few,
two or at most four; it reduced the freeboard from the lofty topsides of
the old ship-of-the-line to an insignificant two or three feet, and thus
made of the target a circular fort and a low-lying strip of armor. It
placed the guns in this circular fort and covered it with armor thick
enough to insure safety against any guns then afloat, and thus, as
perfectly as the engineering means of the day would permit, insured the
combination of offensive and defensive features in maximum degree. It
cleared away at one stroke masts, sails, and all the lofty top-hamper
which since time immemorial had seemed as much an essential feature of
the fighting ship as the guns themselves. It transformed the design of
the fighting ship from the older ideals expressed in the American
frigate "Constitution," or the English "Victory," to the simplest terms
of offence, defence, and steam motive-power. It made of the man-of-war a
machine rather than a ship, an engine of destruction to be operated by
engineers rather than by officers of the ancient and traditional type.
There is small wonder that in all quarters the idea of ships of this
type was not received with enthusiasm. The break with the past was too
definite and complete. The monitor type represented simply the solution
of the problem of naval warfare worked out by a man untrammelled by the
traditions of the past and determined only on reducing such a ship to
the simplest terms of offence and defence as expressed by the
engineering materials and possibilities of the day. Judged from this
standpoint, the vessel seems beyond criticism. She filled perfectly the
ideal set before himself by her designer, and represents as a complete
and harmonious whole what must still be recognized as the most perfect
solution of the problem in terms of the possibilities of those days.
It is proper here that due reference should be made to the claims in
behalf of Mr. Theodore R. Timby as an inventor of the turret and of the
monitor idea as expressed thereby. These claims and the main facts in
the case have long been known, and there should certainly be no attempt
to take from any one his due share in the developments which gave to our
nation a "Monitor" in her hour of need. It is well known that Mr. Timby
between 1840 and 1850 conceived the idea of a revolving fort of iron
mounted with numerous guns and intended to take the place of the masonry
or earth-structures in common use for such purposes. He seems also to
have conceived of a similar structure for use on a ship of low
freeboard, and a model showing such a design was constructed. In 1843 he
filed a caveat for the invention of the revolving turret. Here the
matter apparently rested until 1862, and after the battle between the
"Monitor" and "Merrimac," when he took out a patent which was dated July
8, 1862, covering "a revolving tower for defensive and offensive
warfare, whether on land or water." Ericsson's associates in the
business of building monitors for the Government acquired these patents
of Timby, presumably as shrewd business men, in order to quiet any claim
on his part, and to have the plan available for land forts, should the
opportunity arise to push the business in this direction. There is no
question but that Ericsson was antedated by Timby in the suggestion of a
revolving turret, at least in so far as public notice is concerned.
Ericsson frankly admitted this, and stated that he made no claim to
absolute originality in this respect. He further stated what is
undoubtedly true, that the main idea in the turret, that of a circular
revolving fort, antedates the Nineteenth Century as a whole, and its
origin is lost in the uncertainties of early tradition. It is simply one
of those early ideas which naturally must have been known in essence
since time immemorial, and as such it was the common property of the
engineering practice of the century. It belongs neither to Timby nor to
Ericsson, and no claims regarding priority in this respect are worthy of
serious consideration. The question is not who first conceived the idea
of a revolving fort, but who designed and built the "Monitor" as she
was, and as she met the "Merrimac" on the 9th of March, 1862. The answer
to the latter is too well known a part of the history of the times to
admit of question or to call for further notice. Ericsson's claim for
recognition in this respect rests not on any priority of idea regarding
the use of a circular fort, but rather upon the actual "Monitor" as she
was built and as she crushed at one blow the sea-power of the South, and
representing as it did a completely and carefully designed whole, dating
back to the earlier dealings with Napoleon III. in 1854. This is an age
which judges men by what they do, and judged by this standard Ericsson's
claims in connection with the monitor type of warship are never likely
to be seriously questioned.
Taking Ericsson's life and work, what portion remains as a permanent
acquisition or as a part of the practice of the present age? This is a
question which merits at least a moment's notice.
We should not make the mistake of thinking that permanency is
necessarily a test of merit, or that the value of his services to the
world should be judged by such parts of his work as are plainly apparent
in the practice of the present day. A piece of work must be judged by
the circumstances which brought it forth, and by the completeness and
perfection of its adaptation to the needs and possibilities of its age.
We have then the steam fire-engine; compressed air which he early
employed in England, and which has become an instrument of enormous
importance in connection with the industrial progress of the age,
although this is in no especial degree due to his efforts; the surface
condenser, distiller, and evaporator are a permanently and absolutely
essential part of modern marine practice; the screw-propeller has almost
sole possession of the field of marine propulsion; modern marine engines
and boilers in naval practice are always placed below the water-line and
are protected by deflective deck armor and frequently by coal as well;
the turret has become a permanent and accepted part of the practice of
the age, while the monitor type in its essential feature seems to be
evanescent.
The modern battleship is a vastly more complex structure, and
represents more complex ideas and combinations than did Ericsson's
"Monitor." It contains a battery of guns of the heaviest type known to
naval ordnance. At present such guns are usually of 12-inch bore and
throw a shell of about 800 pounds weight, with an initial velocity of
nearly 3,000 feet per second. Then there is a supporting battery of
guns, 6, 7, or 8 inches in diameter of bore, and finally a secondary
battery of smaller quick-firing guns, throwing shells of from 1 pound to
20 or 30 pounds weight, and added to these there may be a torpedo outfit
as well. The exigencies of fighting ships at sea and in all weathers
seems to have pronounced against the monitor type with its low freeboard
as unsuitable for use on the open sea, while the enormous advances in
modern guns and armor have made a totally different problem of the
distribution of means offensive and defensive. Again, the monitor type
was never intended for long cruising, or indeed for other service than
the defence of coasts and harbors. The policy of building a vessel thus
adapted only to an inner line of defence, and not adapted to an outer
line of defence and offence as well, has been further called in
question, and the judgment of the present day has decided against such
policy. It is true that in the so-called "new navy," begun in 1883, one
monitor, the "Monterey," has been built, while four others of older
type have been somewhat modernized, and there are three monitors
building at the present time. It may be doubted, however, if they will
be followed by others, at least so long as the conditions of naval
warfare and the spirit of public policy remain as they now are.
The monitor type was a perfect solution of the problem of its day, and
nobly it answered the calls made on it. The problem has now changed, the
conditions affecting its solution have also changed, and it is no
discredit to the original type that it now seems to have had its day,
and that it must give way to other forms more perfectly expressing the
spirit of the present age, and the means available for the solution of
present-day problems in the art of naval war.
In many ways, however, the influence of Ericsson's work still lives in
the modern battleship, and while in our modern designs we have gotten
far away from the essential features of the monitor type, yet it is not
too much to say that the germ of the modern battleship is in many ways
found in the "Monitor," especially as expressed in terms of
concentration of heavy gun-fire and localized protection of gun
positions; and in more ways than may be suspected, the influence of
Ericsson and of his work had its part in the developments which have led
to the splendid designs of the present day.
Returning again to our note of the dependence of the present age on
Ericsson, mention may be made of the blower for forcing the combustion
in steam-boilers as a well-established feature of standard marine
practice, and one absolutely essential to the development of the highest
attainable speeds, such as are required in warships, and especially in
those of the torpedo and modern "Destroyer" types. Likewise the use of
the fan for ventilation, as used by him in his early practice, has
become a necessity of modern conditions both on naval and passenger
ships, for the health and comfort of both passengers and crew. His long
series of experiments and his years of labor on air and other forms of
"caloric" engine are only represented by the "Ericsson air-engine" now
on the market, and having its fair share of service in locations where
simplicity of operation and scarcity of water may naturally suggest
its use.
Of his labors in connection with a solar engine, and with other
questions which occupied much of the time of his closing years, we have
but little direct result. Others are at work on the idea of the solar
engine, and it may be that a practicable solution of the problem will
be found.
Ericsson's lasting imprint on engineering practice, curious as it may
seem, was made in his earlier and middle life, rather than in his later
years, and we have even more in the way of permanent acquisition from
his earlier than from his middle years. This results from the fact that
in middle life he was largely engaged on warship designs, admirably
adapted to the needs of the time and to the possibilities of the age,
but no longer suited to either, while in later life he no longer found
it necessary to work at problems which would produce a direct financial
return, and therefore interested himself in a variety of questions
somewhat farther removed from the walks of every-day engineering
practice than those with which he was occupied in earlier life.