Vol. LXIV, No. 10.]

ENGINEERING JOURNAL.

437

expenses which are lessened, such as interest on the addi-
tional equipment which would be needed if it did less
work, including shops, care while not in service, etc.
The purpose of a locomotive is to do work, and its efiiciency
is measured by its capacity for hauling trains, and of keep-
ing in service as many days and running as many miles in
a year as possible.

The Engz’7z.egr says that the discussion thus far shows
(I) that American coal is inferior to English coal, and (2)
American firemen are not equal to their English brethren.
The only reply one can make to this is, perhaps: Some
is, or are—whichever is grammatical—and some is or are
not. The character of American coals and firemen differ
very much from each other, so that it does not seem worth
while to make a general comparison, but probably if an
English fireman should undertake to fire a consolidation
or express engine while running up the grade west of
Piedmont on the Baltimore & Ohio, or Altoona, on the
Pennsylvania Railroad, he would get an experience he
never had before.

Further, our contemporary summarizes by saying that
the discussion shows that it costs more for fuel to haul
heavy trains at slow speeds than would the haulage of
lighter trains at higher speeds. Our assertion is that,
while it may cost more for fuel, the total cost is less, and
that is the important consideration with a railroad company.

Lastly, the writer in the Engmeer concludes what he
chooses to call the “ defects" of the American locomotive
" are the result of the conditions under which it is worked,
not of defects in design or construction, or in want of
adaptability to the work it has to perform.” Itis not easy
to understand just what that means. If it is intended to
say that American locomotives have been designed and
constructed to do the work which they are intended to do,
it is undoubtedly true, and if the converse proposition is
asserted, that English locomotives are not designed o_r
constructed so as to be capable of doing as much work as
American locomotives, it would also probably be true.
If, as the Eizgineer says, their locomotives, both passenger
and goods, are worked as hard as they can be worked, and
if, when they are thus worked their average production of
steam does not exceed 500 lbs. per square foot of grate per
hour, then it is plain from the data we have quoted that
the British iron—horse has not as much bottom as his
American congener.

Mire is not as common in London or Glasgow roads as
it unfortunately is on some American streets, but if such
obstruction to travel does exist there, itis doubtful whether
a brewer in either of those cities would find a horse which
could not pull his beer-wagon out of a “ mud-hole” as
valuable as one which could, even though the latter should
consume more oats than-the former. l

But the question of the relative economy of feed of the
two breeds ‘of iron-horses, as stated by our contemporary,
is not conceded. The dilliculty is to make comparisons of
the performance of engines under like conditions. To
make fair comparisons, the weight and dimensions of en-
gines and trains, the speeds and grades and other circum-
stances must be known. If our contemporary would give
us some reports oflcarefully conducted experiments, it would
throw some light on the subject. But why not adopt the
suggestion made in our last number-—let the Engzfleer and
E2zgz'¢zeerz'7zg News each submit a design of locomotive to
their readers for comparison and criticism. It will then
be their readers’ turn to be amused. »

TWO VALUABLE WATERWAYS.

 

WHILE in many parts of the country there has been a
disposition to abandon the artificial and even the natural
waterways. and to allow them to be superseded by the rail-
roads—-a disposition much to be regretted for many rea-

sons-—-a notable exception is to be found in the two canals _

which connect Hampton Roads with the extensive system
of sounds and rivers of Eastern Carolina.

The older of these is the Dismal Swamp Canal, which
extends from the Elizabeth River south of Norfolk to the
Pasquotank River in North Carolina, and which is one of
the oldest artificial waterways in the country. Chartered
first in 1785, its seven locks, IOO x 18 ft. in size, were con-
sidered engineering feats in their day, and are still in con-
stant use. '

The other, the Albemarle & Chesapeake Canal, is shorter,
but of larger section. It extends from the Elizabeth River
to the North Landing River and has the advantage of the
older work not only in size, but in the fact that it has but a
single lock—- 240 x 95 it. in size-—and that a tidal lock, which
has to be closed only at certain stages of water and in cer-

tain directions of the wind.

To equalize the conditions somewhat, the Dismal Swamp
Canal Company has recently undertaken improvements
which will much increase its capacity. These include an
enlargement of section and the cutting down of the summit
level, so as to dispense with several of the locks, and have
really been made necessary by the increasing traffic.

The commercial importance of these canals can be seen
from the fact that they brought to Norfolk last year 87 per
cent. of the logs which supply the great lumber mills of
that city, a very large proportion of the other forest prod-
ucts reaching the port, a considerable part of the corn, rice
and naval stores, besides carrying a large traffic in mer-
chandise southward bound.

Besides their commercial importance, these canals would
be of great strategic value in case of war. A reference to
the map will show how extended their water connections
are and how much farther still they might be made to
reach. It is to be hoped that before long improvement
and extensions will be undertaken which will give, at a
comparatively small outlay, an inland waterway from New
York Bay to Florida, which mightbe of almostinestimable
value in time of war, and which is sure to be commercially
worth much more than its cost.

In this connection it may be of interest to note that a
very early attempt at steam navigation on canals in this
country was made on the Dismal Swamp Canal. The boat
and its machinery were designed by Mr. Harris and by
Lieutenant W. W. Hunter, of the United States Navy,

 

about 1840, and were for a time operated by Commodore
Marshall Parks, who is still a resident of Norfolk. The
boat is shown in the accompanying diagram. which is pre-
pared from a sketch made by Mr. Parks. There were two
wheels placed horizontally in semi-circular recesses cut in
the sides of the boat ;":these wheels were simply drums