INVENTIONS AT PANAMA. 159 



demonstrated tliis supei-iority, engaged in a little controversy in which patriot- 

 ism 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 ex- 

 perience in public works.* 



The essential difference between the French and American excava- 

 tor 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 bucket- 

 ladder, as in the cut, and sometimes, the motion of the chain and posi- 

 tion 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 w^ays. There are, or have been recently, at work at Panama 

 the following French or Belgian excavators — named resjsectively after 

 the manufacturer or designer, Ville-Chatel, Evrard, Weyer et Riche- 

 mond, 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 accom- 

 panied him in February, 1886. In a subsequent communication to the 

 French Academy of Sciences,! he gave an account of the wreck of a 

 mass of porphyry amounting to thirty thousand cubic metres, on this oc- 

 casion. 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 wnth masonry. Upon a public 

 occasion soon after, De Lesseps held up a fragment of the rock dislo- 

 cated, observing that here was one-billionth part of it! 



* 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, Lieu- 

 tenant C. C Rogers, who has been referred to elsewhere, confirms this. 



f " Bulletin du Canal Interoceanique," May 1, 1886. 



