COMETASY INFLUENCES. 



for the comet in 1680, is shaken by more recent calculations, 

 which give to that body * an elliptic orbit in which the period is 

 8813 years. 



15. The probability of the terrestrial equilibrium being 

 injuriously deranged by the near approach of a comet, which, 

 nevertheless, does not actually come in contact with the earth, is 

 reduced to nothing by the established fact that the masses of 

 these bodies generally are so utterly insignificant that none of 

 them has ever yet produced by its proximity the slightest sensible 

 deviation from its customary path in the smallest body of the 

 solar system. 



16. Notwithstanding the many arguments which we have here 

 developed against the probability of any fatal influence exerted by 

 comets upon our planet, it must not be concealed that high 

 authorities have regarded such influences and effects as not impos- 

 sible. Thus Laplace, referring to the possible collision of a solid 

 comet with the earth, says: "It is easy to foresee the effects of 

 such an eventuality : the earth's axis and rotation changed : the 

 waters of the seas and oceans deserting their beds, and rushing 

 towards the new equator : the chief part of the human race and 

 inferior animals drowned in an universal deluge, or destroyed by 

 the violence of the collision : whole species annihilated : all 

 monuments of human industry overturned ! " Notwithstanding 

 the many and obvious evidences against the geological phenomena 

 having been produced by such a cause, Laplace did not reject it, 

 probably because the phenomena were not so fully known at the 

 time he wrote as they are at present. " We see then," he 

 observed, "why the ocean deserted the most lofty mountains, on 

 which it left, however, incontestable evidence of its presence. We 

 see why the animals and plants of the tropics may have existed in 

 the higher latitudes, where their relics and footsteps are still seen. 

 In fine, it explains the recent date of the present races, whose 

 earliest monuments do not go further back than about 3000 years. 

 The human race, reduced to a small group of individuals, in a 

 deplorable condition, occupied exclusively in providing for their 

 physical wants, must necessarily have lost the remembrances and 

 records of all the sciences and arts ; and when later, new wants 

 were created by the progress of civilisation, all was to be recom- 

 menced as if no previous progress had been made, and as if man 

 had been then for the first time placed upon the earth." 



17. Having disposed of the question of the physical influences 

 imputed to comets, we shall conclude this notice by a brief state- 

 ment of one of the most extraordinary and unexplained phenomena 



* Lardner's " Handbook of Natural Philosophy and Astronomy." (3072). 

 94 



