We come, finally, to the question of inventions in immediate connection with Panama. These seem to consist, thus far, chiefly in an increase in the size and power of the machines, whether dredges or excavators, employed. But ingenuity may at any time supply any need that develops itself, and it has effected part of what has been done already. An opinion formulated by the French Academy of Sciences in 1880, regarding inventions in connection with such work, has been quoted. Lieutenant N. B. Wyse, of the French Navy, whose plan for a sea-level canal was adopted by the Paris Congress, has also touched upon this point. He refers to objections urged against a sea-level canal. The plan involved either a huge tunnel or a huge open cut; in either case the work would be much in excess of any of a like character hitherto attempted. He says, "The course of events, experience based upon precise observation, will undoubtedly suggest new processes, or processes scarcely caught sight of at the present day, so as to conquer the difficulties indicated."["Rapports sur les Études de la Commission Internationals d'Exploration de l'Isthme Américain, par Lucien N. B. Wyse," p. 56. Whatever the services of Lieutenant Wyse in the surveys of the Isthmus, between 1876 and 1879, it should be remarked that his work, published last year, "Le Canal de Panama," is not to be read without allowances. The rupture which occurred between himself and De Lesseps in 1880, due to the fact that Wyse, as he himself tells us, expected to be appointed director-general of the work, and was not so appointed, has led to acrid criticisms on his part upon the company. That part of his work which relates to his surveys—-the larger part—possesses not a little interest, and is not perhaps open to much criticism; but, as regards his strictures upon the company, the fact referred to is to be kept in mind.]

Such anticipations have not been entertained without cause. The major part of the excavation has not yet been done, but already the mechanisms used have been brought to a state of efficiency—one could not say perfection—never reached in the case of any other undertaking. In attempting to trace how this has been brought about, we may begin with one of the first of the new processes introduced, the American method of boring to test the strata and use of the diamond-drill. In September, 1883, the director-general of the works, Dingler, gave an address in Paris upon the then condition of the enterprise, in which he says:
For the great cutting we have made a large number of American soundings. The Americans in this special matter have made considerable progress, and have rendered us very great service.
Ordinarily, when soundings are made, the yield is brought up in a pulverized state, so that the engineer is obliged to make many conjectures as to the quality, of the rock, in order to know what slope to give the excavation.

Generally one is much puzzled. The Americans have discovered a method of bringing up the rock itself in a shape large enough to admit of our judging as to its hardness. A carrot, as the workmen call it, is fetched up. It is obtained by means of a cylinder armed at its lower extremity with black diamonds. This is given a rapid rotary motion; it descends and penetrates into the rock, and in this way we can bring up a block which furnishes the exact consistency of the strata. We placed, before the eyes of the commission, [The "Commission consultative" of engineers.] this morning, a box of specimens taken in Culebra. The result is, that we have a perfect knowledge of the ground, and it is these soundings which enable us to fix our prices.

The following reference to these American soundings occurs in Admiral G. H. Cooper's report to our Government on the progress of the work, dated March 2, 1883. After observing that soundings to ascertain the nature of the soil had been made all along the line, he says:
The first of these soundings were made by French engineers, with the old-fashioned drill and spoon to bring up specimens. This method took many months and was very unsatisfactory; and, finally, the contract for making the remaining soundings was given to Mr. George R. Burt, an American, who is connected with the Panama Railroad Company. Mr. Burt has used the American diamond-drill, and with it has accomplished more work in the past three months than had been done by the other method in the previous two years.

The connection is so close between the consistency of the strata and the slope of the cutting, that the following as to this point will be of interest. The director-general continued:
Well, these borings, made in large numbers at Culebra, showed us that we had to excavate a rock, semi-hard, schistous in quality, having nearly horizontal strata, and that the earth was dry. The result is, that one could not desire better earth for a work of such an exceptional character. We shall be obliged, manifestly, to be very prudent. Accordingly, at the top we have opened the cutting, as if the slope was to be a gentle one. We remove the clayey part which, under the action of water, can be brought to the consistency of paste or mud. Here we have made a very ample opening. But in proportion as we reach clear rock, we make the prism narrower, so as to comprise the cubic contents strictly necessary, with the purpose to make the slope more gradual should experience require it.

The bringing together by an undertaking such as Panama of contractors of divers nationalities, naturally leads to the use of various machines, and it remains to be seen what advantage is to be derived from the sort of rivalry thus established. Here the Panama work may be said to possess an advantage over Suez. The latter was almost exclusively in the hands of French engineers, and was carried through by French contractors and inventors. A single Englishman, Ayton, contracted for a considerable part of the work, but he became bankrupt owing to the withdrawal of forced labor, and the French were obliged to assume his portion. [ Fitzgerald's "Suez Canal," vol. i, p. 200.]. In the case of Panama, contractors of several nationalties have been employed—French, English, Dutch, Swedes, Swiss, Italians, Americans, and Colombians. The "Canal Bulletin" for February 15, 1885, contains a table of contracts, arranged according to nationality, entered into at the time.

After treating of the American use of the diamond-drill, the director-general proceeded to speak of some of the other machines employed. [The diamond-drill has recently been put at Panama to a use other than prospecting. The apparatus of the American Diamond-Drill Company is employed to blast rocks under water. Dynamite is the explosive used, and the rock is so thoroughly shattered that a dredge readily removes it. (See "Canal Bulletin," January 15, 1887.)]. He said:
The excavation is effected in different ways. We are very eclectic at Panama. We reject no system, no method, and as the earth varies at every step, as the works at one point do not resemble those at another, we can try different ways. At certain places we have mellow earth, which is generally composed, in the valleys, of clay mixed with a feldspathic sand. In such places we can make the attack by mechanical processes. We employ excavators.

There are two sorts of excavators, the French and American. The American excavators are very ingenious, and in mellow soil they give satisfactory results. The French excavators are of a type already tested in many places. In clayey and rather adhesive earth they seem preferable. Accordingly, the American papers, knowing, not that we had declared as much, but that facts had demonstrated this superiority, engaged in a little controversy in which patriotism was mixed up. Finally, I wrote to the American contractors that I had never come to any prejudiced decision, that I was wholly disposed to make use of their skill, which I acknowledged to be incontestable, and of their great experience in public works. [Lieutenant W. W. Kimball, United States Navy, in his report to our Government, after his inspection of the canal in January, 1886, claims that the American excavator excels in stony soil and surface soil with roots, while the French machine is better in light soils and sand. The officer of our navy who inspected the works last March, Lieutenant C. C. Rogers, who has been referred to elsewhere, confirms this.]

The essential difference between the French and American excavator is as follows: The French, as has been said, carries a series of buckets attached to an endless chain. The American—with which Americans are comparatively familiar—has a single bucket; it is larger than the French buckets, and is worked at the end of a lever. The French buckets, though smaller, revolve rapidly; their number and constant motion compensate perhaps for their size. Cuts of each system are annexed. It may be remarked as to French excavators, that sometimes the buckets ascend filled with earth below the bucketladder, as in the cut, and sometimes, the motion of the chain and position of the buckets being reversed, above it. The cut of the French excavator is a reduced cut of an illustration in Lieutenant Kimball's government report. That of the American excavator, also that of the American dredge, found farther on, are reduced from illustrations, which appeared in "The Scientific American" in 1884 and 1886. The principle of the French excavator is applied with differences of detail in several ways. There are, or have been recently, at work at Panama the following French or Belgian excavators—named respectively after the manufacturer or designer, Ville-Châtel, Evrard, Weyer et Richemond, Gabert, Boulot, Demange, and Andriessen. There were of the American excavator two types, the Osgood and Otis.

The director-general, after this reference to excavators, observed that in rocky parts excavators could not be used.

In rock excavation a method has recently been tried of breaking up masses of rock by powder and dynamite combined. An explosion of this kind was witnessed by De Lesseps and the party which accompanied him in February, 1886. In a subsequent communication to the French Academy of Sciences, ["Bulletin du Canal Interocéanique," May 1, 1886.] he gave an account of the wreck of a mass of porphyry amounting to thirty thousand cubic metres, on this occasion. The charge consisted of two parts dynamite to one of powder. Some idea of the force of the explosion may be derived from the pains taken to block the passage which led to the charged chamber. For the space of thirty feet it was packed with masonry. Upon a public occasion soon after, De Lesseps held up a fragment of the rock dislocated, observing that here was one-billionth part of it!

The advantage of using powder and dynamite combined is thus explained. If dynamite alone were used, the breakage would be carried too far; the fragments could not be as conveniently loaded by cranes. The effect of powder would be to project the fragments too far, thus damaging, it might be, the neighboring works. As regards the use of dynamite, we might query whether, if a still stronger explosive were employed, the rock might not be reduced to pebbles or sand. In this state it might be handled by the buckets of excavators, and the slower operation of cranes be avoided. We might speculate further, whether the explosives said to have been recently invented in France and Germany, or like substances, might not be of service. If, as is understood, the governments which possess them desire to keep the process of manufacture secret, some difficulty might be experienced in procuring them. But civilization might be the gainer if such inventions were used to blast a thoroughfare at Panama instead of to enhance the rapidity with which human slaughter is carried on. [No secret seems to attach to the composition of a new explosive, bellite, to which an article is devoted in the "Scientific American," May 14, 1887. This explosive, it is stated, has been found more effective in quarries than any nitro-glycerine compound.]

Of all writers who have interested themselves in the Panama Canal no one has given the amount of attention to inventions bestowed by Mr. Bigelow in his report to the New York Chamber of Commerce. We can not do better than give his views upon this topic. These, again, may serve to introduce further particulars as to the machinery employed. After observing that the wages of unskilled labor when work was begun were ninety cents a day, and have since advanced to a minimum of $1.75, and that even at this price the company does not readily get the labor needed, [One of the chief difficulties of the company at present is getting an adequate labor supply. In the "Canal Bulletin," June 16, 1887, the fact is noticed that at several points part of the machinery provided was lying idle, owing to this lack. Several hundred Chinese had arrived but recently, and it was hoped that their labor would prove as effective as that of the Chinese employed upon the Panama Railroad forty years since.] he says:
The question then arises, Must the work be prosecuted under the present conditions ?

"When the Jews were required to make brick without straw, Moses came. May not the exigency, like child-bearing, work its own cure?

In all ages and nations, when manual labor has become too costly to do the work for which there was a universal or even a general need, a substitute for it has been promptly devised. It was to the need of economizing muscular labor that we owe the hoe, the wheelbarrow, and the plow. Had laborers' wages never risen above a shilling a day, we should never have heard of McCormick's reaper, or of Howe's and Singer's sewing-machines. It is equally certain that the portion of our planet which lies under the tropics will never play the part in human history to which its territorial extent and productive power entitle it, until our present assortment of mechanical substitutes for muscular power has been very largely increased. Machines do not mind malaria; they are not poisoned by marshy water; they thrive on the black-vomit; they have no fear of chills or sunstrokes; and, what is more, they are never tired, and will work all the days and nights of their natural lives without interruption, if properly fed and cared for.

That is the class of operatives for out-of-door work in the tropics, and it is to them that M. de Lesseps must, and I presume does, look for an early completion of his canal; for it is in that direction his own remarkable experience has certainly taught him to look with some confidence. When the work on the Suez Canal was begun, and under climatic conditions much the same as those at the Isthmus of Panama, the Suez Canal Company was entitled by its charter to as many native laborers as it required up to forty thousand, and at an almost nominal price. As these men were drafted into the company's service by corvée, England protested against a "revival of slavery" in Egypt. The Khedive was constrained to break his contract with the company, for which he had afterward to pay an indemnity of thirty-eight million francs, and M. de Lesseps had the mortification of seeing his little army of twenty thousand fellahs dispersed as suddenly and as irrevocably as an April fog.

The logic of the situation promptly suggested the replacing of the men with machines; the putting of slaves without souls or sensibilities in the place of slaves with both. The inventive genius of his countrymen was stimulated by the gravity of the crisis, and in due time from eighty to one hundred dredges, with an appropriate supply of barges, elevators, steam-tugs, locomotives, etc., had taken the place of a large portion of the men withdrawn; and this machinery, with only four thousand men, increased the monthly output from ten thousand cubic metres to two million, and executed more excavation in the last three years of the work than had been done in the previous seven. May not the scarcity and cost of manual labor on the Isthmus in like manner develop the means of dispensing with at least that portion which the labor market will not cheerfully supply?

The results already accomplished in that direction justify the expectation that, to a considerable extent, it may. There are already at work on the Isthmus machines for dredging and for excavation, far more powerful and efficient than any ever used on the Suez Canal or anywhere else.

It is the opinion of Mr. Bigelow that De Lesseps's "remarkable experience" at Suez has led him to anticipate the forwarding of the Panama work by similar means. This expectation is illustrated by an incident of the Paris Congress. Lavalley, the inventor of the dredges, was there—was in fact a member; and to him De Lesseps referred at one of the sittings as an engineer "who had already invented so many machines, and who, under similar circumstances, would know how to invent more."

Mr. Bigelow observes, with regard more especially to excavators, "There is no reason to suppose that, in the creation of such machines, art and science have reached a limit in any direction." One might say with Arago:

We can not suppose that a horizon of inventive impossibilities has settled down about Panama.

With regard to Mr. Bigelow's statement that there are at work machines for dredging and excavation "far more powerful" than any ever used elsewhere, it has been already stated that the greater power of these mechanisms is chiefly due to their increased dimensions and the higher steam-power employed. Let us take the "City of New York," the greatest dredge probably ever constructed; built by the American Contracting and Dredging Company, and by them used at Panama. The engines of the largest Suez dredges had a force of seventy-five horse-power. Those of the "City of New York" have a force of three hundred. To run all parts of the complicated machinery, no fewer than eight are employed. The huge ladder which carries the buckets is one hundred and ten feet long; the chain to which the buckets are immediately attached, if ruptured, would reach from the top to the bottom of Bunker Hill Monument. Two discharge-pipes, each three feet in diameter and one hundred and eighty feet long, carry the earth to the banks. By means of steam-pumps, as in the case of the Suez dredges, water is forced into the bell or hopper, and the discharge facilitated. The effectiveness of this mechanism is not due solely to its construction on an enlarged scale; contrivance comes in for part of the credit, and has effected part of the result. One of the peculiarities of the American dredges may be referred to. To steady the vessel and hold the buckets against the bank, two spuds or pile-anchors are employed. In the case of the " City of New York" these spuds are sixty feet high and two feet in diameter. They pass through the hull, one on each side, and the iron chisel-point at the termination of each weighs eighteen hundred pounds. This is planted in the bottom. When spud No. 1 descends, it serves as a pivot around which the dredge, carrying the bucket-ladder in operation, slowly revolves, thus traversing the arc of a circle. When No. 1 is raised, No. 2 is lowered, and serves in like manner as a center. After this fashion, planting a foot at a time, this huge digging, spouting creature, as one might term it, advances. The movement through an arc is regulated by two distance-lines, so called. These are attached to windlasses, one on each side of the forward deck, the other end being attached to the shore. As one line is drawn in, the other is paid out, and by this simultaneous process the motion in curves is maintained. [For these particulars as to the working of the spuds, etc., the writer is indebted to Lieutenant W. W. Kimball, U. S. Navy.] A high degree of interest attaches to a structure combining power, ingenuity, and complexity as these are not united in any other mechanism of the sort. Such among contrivances of the kind is the "City of New York."

With regard to the amount of excavation effected by the dredgers of the American Company, Mr. Bigelow sets it down as about double the largest output of any machine at Suez. Lieutenant Kimball, comparing the output of the later American dredges with the best at Suez, sets it down as more than double, twelve hundred cubic metres per hour, as compared with four hundred and eighty.

While in the matter of dredges Americans have contributed of late more than others by fresh devices and an increase of dimensions, the French seem to have effected like results with regard to excavators. Those first employed at Panama had a force of twenty-four horsepower, while the powerful machines more recently sent out have a force of ninety. The French have lately employed in connection with their excavators a mechanism similar to the élévateur, already described. It is called the transporteur, and consists of an elevated structure which performs the same service for an excavator that the élévateur does for a dredge. The earth is deposited from the buckets upon an endless belt. This passes round two drums about two hundred feet apart, and in the interval rests upon friction-rollers. The earth is thus carried outward from the excavation, and at the same time upward.

While, owing to the power and size of her digging mechanisms, the Panama undertaking has quite an advantage over Suez, it is not to be assumed that this advantage may not be further increased. Upon this contingency the decision of important questions may depend. Whether the canal be finished, at least provisionally, as a lock-canal or cut immediately to the sea-level, is possibly one of these. But the decision as to locks will have to be expeditiously arrived at; and if inventors are to step in and affect in any sort of way the result, they have not much time for contrivance and experiment. At all events, we may hope much from the fact that the undertaking is probably in the best hands to which it could have been intrusted. Owing to the completion of former contracts, or the substitution of later for earlier ones, the greater part of the work devolves at present upon French or American contractors. The portion undertaken by the American company consists, it is true, wholly of dredging—the easiest part of the work. There can be no doubt as to the satisfactory, and, should it prove necessary, rapid completion of this part of the undertaking; the chief difficulty lies in the excavation of dry earth and rock, and this is chiefly in the hands of the French. [According to the plans of the company, as described recently by Charles de Lesseps, vice-President of the Suez and Panama Companies, part of the work which it was thought must be done by excavators may be effected by dredging. With this end in view, he tells us, the company is making preparations. It is proposed to introduce into the works, between Gamboa and Paraiso, the waters of the upper Chagres. An analogous plan served the same purpose at Suez: fresh water was introduced from the Nile; nine dredges were carried up by a lock and floated upon it. These operated upon a temporary lake, whose level was seventeen feet above the Mediterranean. Whether such a plan, by some thought impracticable, may be successfully applied at Panama, remains to be seen.

For a description of the manner in which the water was employed, see Fitzgerald, vol. i, pp. 190-194.] But American inventions and skill may be as serviceable here as in any other section of the work. It is a pledge of earnest effort that the two republics which have the work in charge have also a greater stake than others in the completion of the undertaking—France, because French capital has furnished the funds; America, because of our need of a shorter water-way between our Atlantic and Pacific coasts. And certainly no other nations offer greater achievements in inventions and execution as a guarantee of success.

Nothing, perhaps, so strongly characterizes this century as the advance man is making in exploring, understanding, and obtaining a mastery over Nature. This process of mastery could scarcely proceed in a more instructive way than by tracing its stages in the instances we have considered. The Alps and the two Isthmuses illustrate it in a not unfitting way. It is safe, probably, to say that the power to excavate earth, to excavate and blast rock, is from five to ten times as great as when a man, wholly unknown to fame, landed with a handful of his countrymen where the city of Port Said now stands and began the excavation of Suez.

In regard to the present enterprise upon the American Isthmus, if we take into account its magnitude and the difficulties involved, it represents without doubt the greatest effort in the line of industry and peaceful achievement man has yet put forth. De Molinari, the Belgian economist, computed that the stock of machinery for the excavation represented the labor of half a million men. Such a fact indicates how far the process of conquering Nature has been carried. The world is watching, with no doubt a degree of skepticism, the way in which the remaining work is being done; and in scientific circles especially an eager interest will continue to be manifested in this great struggle of skill and inventive genius against the forces and obstinacy of Nature. It may be protracted, but it must be in the end successful.