SINGULAR ARRANGEMEMT OF STRATA. ^^ 



all cases to explain, but at least to observe accurately, and 

 to make known, because they are of importance to an art of 

 essential utility, an art founded on observation, that of the 

 miner. 



The course of the strata of combustible minerals and me- Lead to a 

 tallic veins, their various directions and inclinations, their ^^","^!^5^ ^'^' 

 bendings, turns, faults, disappearance, and change of posi- 

 tion, their impoverishment, &c. ; all these different states, 

 all these moditications, appear to depend on the arrange- 

 ment of the strata of our globe, and the concussions they 

 may have experienced at different periods, whatever the 

 causes may have been. Perhaps therefore it is not useless, 

 to make known any singularities of this kind, hitherto little 

 observed, that may offer themselves. ^ 



Since it is from the bosom of the earth we derive the ma- Tlience usef4 

 terials of our most useful arts, minerals, to study its inter- *° ^^^^ '"'"^'"* 

 nal constitution is of importance, as this would frequently 

 lead to the solution of the difficulties that present themselves 

 to the miner, or at least diminish their number. His pro- 

 gress therefore, being less uncertain, would be much less 

 expensive. 



If my reasoning be just, I shall bring forward with more The author's 

 confidence a few observations, that appear to me to claim ^^^'™ '° ^'^"*'' 

 the attention of geologists, from the singularity of the facts. 

 They may confide in what I have the honour to lay before 

 them, since, as I am not sufficiently initiated into natural 

 history to form systems, I have always confined myself to 

 observation, and to observe long before I copy ; and in the 

 present instance I have the confirmation of several fellow tra- 

 vellers, among others the senator Aboville, whose accuracy 

 of observation is well known. ^ 



The table land of Jura, on which stands the city of Pon- Jura, 

 tarlier, is furrowed by a few valleys, more or less close. One 

 of the most interesting is that of la Lone, on account of its Vale of U 

 wild and picturesque scenery, and the various works con- '^^^' 

 structed on the banks of the river. It is rendered particu- 

 larly remarkable by the source of the river itself. I do not 

 think the reader will be displeased with ray saying something 

 here of this wonder of Jura, as it may be styled, which de- 



VoL, XX.— May, 1S08. F servea 



