1S94.] J "^^ [Lyman. 



the outcrop was sometimes (for example, iu the case of the Palisade trap) 

 more thaa fifty miles long aucl "as crooked as a ram's horn," the vertical 

 parts of the dike must, by a marvelous coincidence, have followed the 

 same curves. Gndat Judwus Apella, non ego! Really, such a belief 

 seems to require an amount of credulity hardly consistent with the mod- 

 ern scientific spirit that hesitates to accept extraordinary explanations 

 where ordinary ones can be found to answer the purpose. 



The intrusive conjecture has in fact been in great part rejected, but not 

 hitherto for the Palisade trap, owing to certain observed facts. Still, it 

 seems not at all impossible to account for them, so far as recorded, much 

 more easily and naturally" than by the well-nigh supernatural intrusive 

 theory. If the trap appears in one place to cross the sedimentary beds on 

 one side, why may it not be either the side of a dike (foi*, of course, every 

 overflow must come from a dike somewhere) or merely an evidence of the 

 erosion that took place before the trap overflowed ; just as in the case of 

 the "horsebacks" or "rock faults" iu coal mines, a small valley in the 

 original coal marsh has been filled with sand or silt? If there be here 

 and there a branch from the bottom of the trap sheet running a short 

 distance into the sedimentary beds, is it not as easily conceivable in the 

 case of an overflow as in that of intrusion? Is it wholly inconceivable 

 that apparently similar branches from the upper surface of a trap overflow 

 sheet into the sedimentary beds might sometimes occur, though none are 

 positively recorded? If there be "indurated shales " above some of the 

 Palisade trap, is it not quite possible, in case of real "induration," that 

 there be another overlying unexposed bed of trap that may have caused 

 it, especially as there is other evidence of interbedded shales ? The intru- 

 sion conjecture is beset with so many serious difiiculties, and the overflow 

 theory with so few, the choice between them seems easy. A vast amount 

 of ingenuity has been expended in trying to reconcile observed facts with 

 the intrusive theory, while immensely less skill is required to show the 

 consistency of the facts with the overflow principle. 



The New Red theory, with its conjectures and arguments, both for the 

 trap and the sediments, might well be called the tennis ball of American 

 geologists, or a domestic appliance for mental gymnastics, requiring the 

 minimum of work in the field. Nevertheless the f\ibric, composed, as we 

 have just seen, in the main wholly of conjectures, based one upon 

 another, without having at the bottom one single substantiated fact, has 

 with the lapse of time become so consolidated, and in its older parts, dat- 

 ing from the early infancy of geology in America, has become so vener- 

 ated that it may now be considered to be a fuUj^ ' ' accepted fable." The 

 hand that attempts to disturb it may probably be regarded as sacrilegious ; 

 and arguments against it, though thoroughly founded on facts, will be 

 looked on with more suspicion than new conjectures would be if only 

 consonant with the old baseless ones. But however stubbornly skeptical 

 the public may be in refusing to put faith in the present conjectures, well 

 supported by many observations, instead of the old ones, supported only 



