RIO DE JANEIRO AND ITS ENVIRONS. 57 



hundred men, relieving each other alternately, have been 

 at work day and night, excepting Sundays, for seven 

 years. The sound of hammer and pick during that time 

 has hardly ever been still, and so hard is the rock through 

 which the tunnel is pierced, that often the heaviest blows 

 of the sledge yield only a little dust, no more in bulk 

 than a pinch of snuff.* 



On our return we were detained for half an hour at 

 a station on the bank of the rjver Parahyba. This first 

 visit to one of the considerable rivers of Brazil was not 

 without its memorable incident. One of our friends of 

 the Colorado, who parts from us here on his way to San 

 Francisco, said he was determined not to leave the expe- 



* TJiis road, which is but the beginning of railroad travel in Brazil, 

 opens a rich prospect for scientific study. From this time forward the dilliculty 

 of transporting collections from the interior to the seaboard will be diminish 

 ing. Instead of the few small specimens of tropical vegetation now preserved 

 in our museums, I hope that hereafter, in every school where geology and 

 palasontology are taught, we shall have large stems and portions of trunks 

 to show the structure of palms, tree-ferns, and the like, trees which represent 

 in modern times the ancient geological forests. The time is coming when our 

 text-books of botany and zoology will lose their local, limited character, and 

 present comprehensive pictures of Nature in all her phases. Then only will 

 it be possible to make true and pertinent comparisons between the condi 

 tion of the earth in former times and its present aspect under different zones 

 and climates. To this day the fundamental principle guiding our identification 

 of geological formations in different ages rests upon the assumption that each 

 period lias had one character throughout ; whereas the progress of geology is 

 daily pressing upon us the evidence that at each period different latitudes and 

 different continents have always had their characteristic animals and plants, if 

 not as diversified as now, at least varied enough to exclude the idea of uni 

 formity. Not only do I look for a vast improvement in our collections with 

 improved methods of travel and transportation in Brazil, but I hope that 

 scientific journeys in the tropics will cease to be occasional events in the- 

 pi-ogress and civilization of nations, and will be as much within the reach of 

 every student as journeys in the temperate zone have hitherto been. For r ur- 

 tlier details respecting the building of this road, see Appendix Xo. IV. LA. 



