23Q NICOLAUS STENO 



2. At the time when one of the upper strata was being 

 formed, the lower stratum had already gained the consistency 

 of a solid. 



3. At the time when any given stratum was being formed it 

 was either encompassed on its sides by another solid substance, 

 or it covered the entire spherical surface of the earth. Hence 

 it follows that in whatever place the bared sides of the strata are 

 seen, either a continuation of the same strata must be sought, or 

 another solid substance must be found which kept the matter of 

 the strata from dispersion. 



4. At the time when any given stratum was being formed, 

 all the matter resting upon it was fluid, and, therefore, at the 

 time when the lowest stratum was being formed, none of the 

 upper strata existed. 



As regards form, it is certain that at the time when any given 

 stratum was being produced its lower surface, as also its lateral 

 surfaces, corresponded to the surfaces of the lower substance 

 and lateral substances, but that the upper surface was parallel 

 to the horizon, so far as possible ; and that all strata, therefore, 

 except the lowest, were bounded by two planes parallel to the 

 p. 31. horizon. Hence it follows that strata either perpendicular to 

 the horizon or inclined toward it, were at one time parallel to 

 the horizon. 



Moreover, the changed position of strata and their exposed 

 sides, such as are seen to-day in many places, do not contradict 

 my statements ; since in the neighborhood of those places evi- 

 dent traces of fires and waters are to be found. For just as 

 water disintegrating earthy material carries it down sloping 

 places not only on the surface of the earth but also in the earth's 

 cavities ; so fire, breaking up whatever solids oppose it, not only 

 drives out their lighter particles but also sometimes hurls forth 

 their heaviest weights ; and the result is that on the surface of 

 the earth are formed steeps, channels, and hollows, while in the 

 bowels of the earth subterranean passages and caverns are pro- 

 duced. 



By reason of these causes the earth's strata can change posi- 

 tion in two ways : 



