Scientific American Supplement, No. 344, August 5, 1882

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During the whole of the seventeenth and eighteenth centuries, Spain
had need of the best mode of conveyance for her treasures across the
isthmus. Yet those from Peru came by the miserable route from Panama to
the deadliest of climates. Porto Bello and her European wares for
her colonies toiled up the Chagres river, while the roughest of
communication farther north connected the Chimalapa and the Guasacoalcos
in Mexico, and the trade there was limited sternly to but one port on
each side. As late as Humboldt's visit, in 1802, when remarking upon the
"unnatural modes of communication" by which, through painful delays, the
immense treasures of the New World passed from Acapulco, Guayaquil,
and Lima, to Spain, he says: "These will soon cease whenever an active
government, willing to protect commerce, shall construct a good road
from Panama to Porto Bello. The aristocratic nonchalance of Spain, and
her fear to open to strangers the way to the countries explored for her
own profit, only kept those countries closed." The court forbade, on
pain of death, the use of plans at different times proposed. They
wronged their own colonies by representing the coasts as dangerous and
the rivers impassable. On the presentation of a memoir for improving the
route through Tehuantepec, by citizens of Oaxaca, as late as 1775,
an order was issued forbidding the subject to be mentioned. The
memorialists were censured as intermeddlers, and the viceroy fell under
the sovereign's displeasure for having seemed to favor the plans.

The great isthmus was, however, further explored by the Spanish
government for its own purposes; the recesses were traversed, and the
lines of communication which we know to-day were then noted.

In addition to the fact that comparatively little was explored north or
south of that which early became the main highway, the Panama route,
there is confirmation here of the truth that Spain concealed and even
falsified much of her generally accurately made surveys. No stronger
proof of this need be asked than that which Alcedo gives in connection
with the proposal by Gogueneche, the Biscayan pilot, to open
communication by the Atrato and the Napipi. "The Atrato," says the
historian, "is navigable for many leagues, but the navigation of it is
prohibited under pain of death, without the exception of any person
whatever."

The Isthmus of Nicaragua has always invited serious consideration for
a ship canal route by its very marked physical characteristics, among
which is chiefly its great depression between two nearly parallel ranges
of hills, which depression is the basin of its large lake, a natural and
all-sufficient feeder for such a canal.

In 1524 a squadron of discovery sent out by Cortez on the coast of the
South Sea, announced the existence of a fresh water sea at only
three leagues from the coast; a sea which, they said, rose and fell
alternately, communicating, it was believed, with the Sea of the North.
Various reconnoissances were therefore made, under the idea that here
the easy transit would be established between Spain and the spice lands
beyond.

It was even laid down on some of the old maps, that this open
communication by water existed from sea to sea; while later maps
represented a river, under the name of Rio Partido, as giving one of
its branches to the Pacific Ocean and the other to Lake Nicaragua. An
exploration by the engineer, Bautista Antonelli, under the orders of
Philip II., corrected the false idea of an open strait.

In the eighteenth century a new cause arose for jealousy of her
neighbors and for keeping her northern part of the isthmus from their
view. In the years 1779 and 1780 the serious purposes of the English
government for the occupancy of Nicaragua, awakened the solicitudes of
the Spanish government for this section. The English colonels, Hodgson
and Lee, had secretly surveyed the lake and portions of the country,
forwarding their plans to London, as the basis of an armed incursion,
to renew such as had already been made by the superintendent of the
Mosquito coast, forty years before, when, crossing the isthmus, he took
possession of Realejo, on the Pacific, seeking to change its name to
Port Edward. In 1780, Captain, afterward Lord Nelson, under orders from
Admiral Sir Peter Parker, convoyed a force of two thousand men to San
Juan de Nicaragua, for the conquest of the country.

In his dispatches, Nelson said: "In order to give facility to the great
object of government, I intend to possess the lake of Nicaragua, which,
for the present, may be looked upon as the inland Gibraltar of Spanish
America. As it commands the only water pass between the oceans, its
situation must ever render it a principal post to insure passage to the
Southern Ocean, and by our possession of it Spanish America is severed
into two."

The passage of San Juan was found to be exceedingly difficult; for the
seamen, although assisted by the Indians from Bluetown, scarcely forced
their boats up the shoals. Nelson bitterly regretted that the expedition
had not arrived in January, in place of the close of the dry season. It
was a disastrous failure, costing the English the lives of one thousand
five hundred men, and nearly losing to them their Nelson.

At this period, Charles III., of Spain, sent a commission to explore the
country. These commissioners reported unfavorably as regarded the route;
but fearing further intrusion from England, forbade all access to the
coast; even falsifying and suppressing its charts and permanently
injuring the navigation of the San Juan and the Colorado by obstructions
in their beds.

It is, however, a relief here to learn that when Humboldt visited the
New World, he could say: "The time is passed when Spain, through a
jealous policy, refused to other nations a thoroughfare across the
possessions of which they kept the whole world so long in ignorance.
Accurate maps of the coasts, and even minute plans of military
positions, are published." It is also true that the Spanish Cortes,
in 1814, decreed the opening of a canal, a decree deferred and never
executed.

It was reserved for our century to see this great project carried into
execution, and it is but just that as a chronicler of events I should
connect with the Canal of Panama the name of a family who have done much
to bring the scheme, so to say, into practical execution.

As early as the year 1836, Mr. Joly de Sabla turned his views toward the
cutting of a canal across the Isthmus of Panama. He resided at the time
on the Island of Guadeloupe, one of the French West India Islands,
where he possessed large estates. Of a high social position, the
representative of one of France's ancient and noble families, with large
means at his disposal and of an enterprising spirit much in advance of
his time, he was well calculated to carry out such a grand scheme.

He soon set about procuring from the Government of New Granada (now
Colombia) the necessary grants and concessions, but much time and many
efforts were spent before these could be brought to a satisfactory
condition, and it was not until the year 1841 that he could again visit
the Isthmus, bringing with him this time, on a vessel chartered by him
for the purpose, a corps of engineers and employes, medical staff, etc.,
etc. After two years spent in exploring and surveying a country at that
time very imperfectly known, he returned to Guadeloupe to find his
residence and most of his estates destroyed by the terrible earthquake
that visited the island in February, 1843.

Undaunted by this unexpected and severe blow, Mr. De Sabla persisted in
his efforts, and in the same year obtained from the French government
the establishment of a Consulate at Panama to insure protection to the
future canal company, and also the sending of two government engineers
of high repute (Messrs. Garella and Courtines), to verify the surveys
already made and complete them.

After receiving the respective reports of Garella and Courtines, Mr.
De Sabla decided upon first constructing a railway across the Isthmus,
postponing the cutting of the canal until this indispensable auxiliary
should have rendered it practicable and profitable. He then presented
the scheme in that shape to his friends in Paris and London, and formed
a syndicate of thirteen members, among whom we may recall the names of
the well known Bankers Caillard of Paris, and Baimbridge of London,
of Sir John Campbell, then Vice President of the Oriental Steamship
Company, of Viscount Chabrol de Chameane, and of Courtines, the
exploring engineer.

A new contract was then entered upon with New Granada in June, 1847, and
early in 1848, the Syndicate was about to forward to the Isthmus the
expedition which was to execute the preliminary works, while the company
was being finally organized in Paris, and its stock placed.

The success of the undertaking seemed to be assured beyond peradventure,
when the unexpected breaking out of the French revolution in February,
1848, dashed all hopes to the ground. Several of the prominent
financiers engaged in the affair, taken by surprise by the suddenness of
the revolution, had to suspend their payments and of course to withdraw
from the Panama Canal and railroad scheme. Others withdrew from
contagious fear and timidity. Finally the term fixed for carrying out
certain obligations of the contract expired without their fulfillment
by the company, and the concession was forfeited. Another contract was
almost immediately applied for and granted with unseemly haste by the
President of New Granada to Messrs. Aspinwall, Stephens and Chauncey,
which resulted in the construction of the actual Panama Railroad.

These gentlemen acted fairly in the matter, and in 1849, calling Mr.
De Sabla to New York, offered him to join them in the new scheme.
Unfortunately they had decided upon placing the Atlantic terminus of the
railroad upon the low and swampy mud Island of Manzanillo, while Mr.
De Sabla insisted on having it on the mainland on the dry and healthy
northern shore of the Bay of Limon. They could not come to an
understanding on this point, and Mr. De Sabla, whose experience and
foresight taught him the dangers that would result to the shipping from
the unprotected situation of the projected part (now Colon--Aspinwall),
and who well knew the insalubrity of the malarial swamp constituting
the Island of Manzanillo, withdrew forever from the undertaking, after
having devoted to it without any benefit to himself, the best years of
his life and a large portion of his private means.

One of his sons, Mr. Theodore J. de Sabla, after having actively
co-operated with Lieutenant Commander Wyse, in the original scheme
of the present canal company, is now one of Count de Lesseps's
representatives in the City of New York, and a director of the Panama
Railroad Company.

* * * * *

IMPROVED AVERAGING MACHINE.

At the recent meeting of the American Society of Civil Engineers, in
this city, a paper on an improved form of the averaging machine was read
by its inventor, Mr. Wm. S. Auchincloss.

The ingenious method by which the weight of the platform is eliminated
from the result of the work of the machine was exhibited and explained.
This is accomplished by counterweights sliding automatically in tubes,
so that in any position the unloaded platform is always in equilibrium.
Any combination of representative weights can then be placed on this
platform at the proper points of the scale. By then drawing the platform
to its balancing point, the location of the center of gravity will at
once be indicated on the scale by the pointer over the central trunnion.

The weights may be arranged on a decimal system, with intermediate
weights for closer working, or they may be made so as to express
multiples or factors.

Each machine is provided with a number of differing scales, divided
suitably for various purposes. When the problem is one of time, the
scale represents months and days; for problems of proportion, the zero
of the scale is at the center of its length; for problems for the
location of center of gravity of a system from a fixed point, the zero
is at the extremity of the scale, etc.

The machine exhibited has sixty-three transverse grooves, which, by
arrangement of weights, can be made to serve the purposes of two hundred
and fifty-two grooves.

The machine is 29 inches in length, 9 inches in width, and weighs about
13 pounds.

With the machine can be found average dates, as, for instance, of
purchases and of payments extending over irregular periods; also average
prices, as for "futures," in comman use among cotton brokers. The
problem of average haul, so often presented to the engineer, can be
solved with ease and great celerity. Practical examples of the solution
of these and a number of other problems involving proportions or
averages were given by the author.

* * * * *

COMPOUND BEAM ENGINE.

The engine represented in Figs. 1 to 4 herewith is intended for a mill,
and is of 530 to 800 indicated horse-power, the pressure being seven
atmospheres, and the number of revolutions forty-five per minute. As
will be seen by the drawing each cylinder is placed in a separate
foundation plate, the two connecting rods acting upon cranks keyed
at right angles upon the shaft, W, which carries the drum, T. The
high-pressure cylinder, C, is 760 mm diameter, the low pressure cylinder
being 1,220 mm. diameter, and the piston speed 2.28 m. The drum, which
also fulfills the purpose of a fly wheel, is provided with twenty-eight
grooves for ropes of 50 mm. diameter. With the exception of the
cylinders, pistons, valves, and valve chests, the engines are of the
same size, corresponding to the equal maximum pressures which come into
action in each cylinder, and in this respect alone the engine differs in
principle from an ordinary twin machine.

[Illustration: BORSIG'S IMPROVED COPOUND BEAM ENGINE. FIG. 1]

The steam passes from the stop-valve, A, Fig. 4, through the steam pipe,
D, to the high pressure cylinder, C, and having done its work, goes into
the receiver, R, where it is heated. From the receiver it is led into
the low-pressure cylinder, C1, and thence into the condenser. Provision
is made for working both engines independently with direct steam when
desired, suitable gear being provided for supplying steam of the proper
pressure to the condensing engine, so that each engine shall perform
exactly the same amount of work. The starting gear consists of a
hand-wheel, H, which controls the stop valve, A, and of another h, which
opens the valves for the jackets of the cylinders and receiver. The
hand-wheel, h1 and h2, govern the valves, which turn the steam direct
into the two cylinders. There are also lever, g, which opens the
principal injection cock, H1, and the auxiliary injection cock, H2, the
function of which is to assist in forming a speedy vacuum, when the
engine has been standing for some time.

[Illustration: BORSIG'S IMPROVED COPOUND BEAM ENGINE. FIG. 2]

The drum is 6.08 m. diameter, the breadth being 2.04 m., with a total
weight of 33,000 kilos. The beams are of cast iron with balance weights
cast on. The connecting rods and cross beams are of wrought iron, and
the cranks, crank shaft, piston rods, valve rods, etc., of steel. The
bed-plate for the main shaft bearings are cast in one piece with the
standards for the beam, which are connected firmly together by the
center bearing, M M1, which is cast in one piece, and also by the
diagonal bracing piece, N N1. The construction of the cylinder and valve
chests is shown in Fig. 1. The working cylinder is in the form of a
liner to the cylinder, thus forming the steam jacket, with a view to
future renewal. This lining has a flange at the lower part for bolting
it down, being made steam-tight by the intervention of a copper packing
ring. There is a similar ring at the upper part which is pressed down by
the cylinder cover. The latter is cast hollow and strengthened by ribs.
The pistons are provided with cast iron double self-expanding packing
rings. For preventing accidents by condensed water, spring safety
valves, ss and s1 s1, are connected to the valve chests. The valve gear,
which is arranged in the same manner for both cylinders, is actuated
by shafts, w and w1, rotated by toothed wheels as shown. Motion is
communicated from the way-shafts, w and w1, by the eccentrics, and the
eccentric rods, e1 e2 e3 e4, and the levers and rods belonging thereto,
to the short steam valve rocking shafts levers, f1 f2 f3 f4, and the
exhaust valve rocking shafts, k1 k2 k3 k4, the bearings of which are
carried on brackets above the valve chests, which, being furnished with
tappet levers, raise and lower the valves.

[Illustration: BORSIG'S IMPROVED COPOUND BEAM ENGINE. FIG. 3]

The valves are conical, double-seated, and of cast iron, and the inlet
and outlet valves are placed the one above the other, the seats being
also conically ground and inserted through the cover of the valve chest.
Both inlet and outlet valves are actuated from above, and are removable
upward, an arrangement which admits of the valves being more easily
examined than when the two are actuated from different sides of the
valve chest. To carry out this idea the inlet valves are furnished with
two guides, which, passing upward through the stuffing-box, are attached
to a hard steel cross piece, which receives the action of a bent catch
turning on a pin attached to the levers, t1, t2, t3, t4. The exhaust
valves, on the contrary, have only one guide each, which passes upward
through the seat of the admission valve, through the valve itself by
means of a collar, and through the stuffing-box. It is furnished with
hard steel armatures, through which the levers, z1 z2, Fig. 3, act upon
the exhaust valves.

[Illustration: BORSIG'S IMPROVED COPOUND BEAM ENGINE. FIG. 4]

The governor effects the acceleration or retardation of the loosening of
the catch actuating the steam valve by means of hard steel projections
on the shaft, v1, the position of which, by means of levers, is
regulated by the governor, which in its highest position does not allow
the lifting of the inlet valve at all. The regulation of the expansion
by the governor from 0 to 0.45 takes place generally only in the case of
the high-pressure cylinder, while the low-pressure cylinder has a fixed
rate of expansion. Only when the low-pressure cylinder is required
to work with steam direct from the boiler is the governor applied to
regulate the expansion in it. An exact action in the valve guides and
a regular descent is secured by furnishing them with small dash pot
pistons working in cylinders. Into them the air is readily admitted by
a small India-rubber valve, but the passage out again is controlled at
pleasure.--_The Engineer_.

* * * * *

TO DETECT ALKALIES IN NITRATE OF SILVER--Stolba recommends the salt
to be dissolved in the smallest quantity of water, and to add to
the filtered solution hydrofluosilicic acid, drop by drop. Should a
turbidity appear an alkaline salt is present. But should the liquid
remain limpid, an equal volume of alcohol is to be added, which will
cause a precipitate in case the slightest trace of an alkali be present.

* * * * *

POWER HAMMERS WITH MOVABLE FULCRUM.

[Footnote: Paper read before the Institution of Mechanical
Engineers.--_Engineering_.]

By DANIEL LONGWORTH, of London.

The movable-fulcrum power hammer was designed by the writer about five
and a half years ago, to meet a want in the market for a power hammer
which, while under the complete control of only one workman, could
produce blows of varying forces without alteration in the rapidity with
which they were given. It was also necessary that the vibration and
shock of the hammer head should not be transmitted to the driving
mechanism, and that the latter should be free from noise and liability
to derangement. The various uses to which the movable fulcrum hammers
have been put, and their success in working[1]--as well as the
importance of the general subject which includes them, namely, the
substitution of stored power for human effort--form the author's excuse
for now occupying the time of the meeting.

[Footnote 1: The hammers have been for some years used by A. Bamlett, of
Thirsk; the American Tool Company, of Antwerp; Messrs. W.&T. Avery, of
Birmingham; Pullar & Sons, of Perth; Salter & Co., of West Bromwich;
Vernon Hope & Co., of Wednesbury, etc.; and also for stamps by Messrs.
Collins & Co., of Birmingham, etc.]

Until these hammers were introduced, no satisfactory method had been
devised for altering the force of the blow. The plan generally adopted
was to have either a tightening pulley acting on the driving belt, a
friction driving clutch, or a simple brake on the driving pulley, put in
action by the hand or foot of the workman. Heavy blows were produced
by simply increasing the number of blows per minute (and therefore the
velocity), and light blows by diminishing it--a plan which was quite
contrary to the true requirements of the case. To prevent the shock
of the hammer head being communicated to the driving gear, an elastic
connection was usually formed between them, consisting of a steel spring
or a cushion of compressed air. With the steel spring, the variation
which could be given in the thickness of the work under the hammer was
very limited, owing to the risk of breaking the spring; but with the
compressed air or pneumatic connection the work might vary considerably
in thickness, say from 0 to 8 in. with a hammer weighing 400lb. The
pneumatic hammers had a crank, with a connecting rod or a slotted
crossbar on the piston-rod, a piston and a cylinder which formed the
hammer-head. The piston-rod was packed with a cup leather, or with
ordinary packing, the latter required to be adjusted with the greatest
nicety, otherwise the piston struck the hammer before lifting it, or
else the force of the blow was considerably diminished. As the piston
moved with the same velocity during its upward and downward strokes,
and, in the latter, had to overtake and outrun the hammer falling under
the action of gravity, the air was not compressed sufficiently to give
a sharp blow at ordinary working speeds, and a much heavier hammer was
required than if the velocity of the piston had been accelerated to a
greater degree.

As it is impossible in the limits of this paper to describe all the
forms in which the movable fulcrum hammers have been arranged, two types
only will be selected taken from actual work; namely, a small planishing
hammer, and a medium-sized forging hammer.[1]

[Footnote 1: To the makers, Messrs. J. Scott Rawlings & Co, of
Birmingham, the author is indebted for the working drawings of these
hammers.]

The small planishing hammer, Figs. 1 to 3, next page, is used for
copper, tin, electro, and iron plate, for scythes, and other thin work,
for which it is sufficient to adjust the force of the blow once for all
by hand, according to the thickness and quality of the material before
commencing to hammer it. The hammer weighs 15 lb., and has a stroke
variable from 21/2 in. to 91/2 in., and makes 250 blows per minute. The
driving shaft, A, is fitted with fast and loose belt pulleys, the belt
fork being connected to the pedal, P, which when pressed down by the
foot of the workman, slides the driving belt on to the fast pulley and
starts the hammer; when the foot is taken off the pedal, the weight on
the latter moves the belt quickly on to the loose pulley, and the hammer
is stopped. The flywheel on the shaft, A, is weighted on one side,
so that it causes the hammer to stop at the top of its stroke after
working; thus enabling the material to be placed on the anvil before
starting the hammer. The movable fulcrum, B, consists of a stud, free to
slide in a slot, C, in the framing, and held in position by a nut and
toothed washer. On the fulcrum is mounted the socket, D, through which
passes freely a round bar or rocking lever, E, attached at one end to
the main piston, F, of the hammer, G, and having at the other extremity
a long slide, H, mounted upon it. This slide is carried on the
crank-pin, I, fastened to the disk, J, attached to the driving shaft, A.
The crank-pin, in revolving, reciprocates the rocking lever, E, and
main piston, F, and through the medium of the pneumatic connection, the
hammer, G. The slide, H, in revolving with the crank-pin, also moves
backward and forward along the rocking lever, approaching the fulcrum,
B, during the down-stroke of the hammer, and receding from it during
the up-stroke. By this means the velocity of the hammer is considerably
accelerated in its downward stroke, causing a sharp blow to be given
while it is gently raised during its upward stroke.

To alter the force of the blow, the hammer, G, is made to rise and fall
through a greater or less distance, as may be required, from the fixed
anvil block, K, after the manner of the smith giving heavy or light
blows on his anvil. It is evident that this special alteration of the
stroke could not be obtained by altering the throw of a simple crank and
connecting rod; but by placing the slot, C, parallel with the direction
of the rocking lever, E, when the latter is in its lowest position, with
the hammer resting on the anvil, and with the crank at the top of its
stroke, this lowest position of the rocking lever and hammer is made
constant, no matter what position the fulcrum, B, may have in the slot,
C. To obtain a short stroke, and consequently a light blow, the fulcrum
is moved in the slot toward the hammer, G; and to produce a long stroke
and heavy blow the fulcrum is moved in the opposite direction.

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