A. a Twining on the Earthquake of October, 1870. 53 



pot of the disturbance. The subject, in this view of it, merits 

 inore extended investigation, and it is hoped that the state- 

 Qcnt here brought out will induce new communications relative 



the facts. 



The interpretation of Mr. McCord's interesting statements 

 elative to the telegraphic communication, seems to be as fol- 

 ows : He occupied the last eight seconds of the motion at Que- 

 )ef with a question put to Montreal That question, together 



•1 tlie answer "no," I find by careful trial at the American 



1 _iapli office, require not less than eighteen seconds fo] 



less than forty-two seconds between the end of the message and 

 c)f the tremors at Quebec, and the end of the same at Montreal, 

 ninety-six miles distant in longitude, and one hundred and fifty- 

 nine m a Kne K 51° E., and which in the table above had been 

 and still remains credited with the empirical interv-al of thirty- 

 nine seconds, — showing a near accordance between these and 

 the other facts, and 137 miles per minute of east-and-west pro- 



Again, the Montreal "no" was given just as the tremors there 

 began, and after— say six seconds after— the end of the shock 

 at Quebec ; that is to say, the beginning traversed from city to 

 city in some six seconds more than the duration of the shock. 

 Consequently the latter, in consistency with the above, must 

 have continued about thirty -six seconds, in place of the twenty- 

 six seconds ascertained at'New Haven. Still again, the shock 

 at Montreal began with the "no," which may have occupied 

 four seconds. Then there were fifteen seconds of interv-al ; 

 then eight of reply ; then nine to ten of estimated continuance ; 

 in all thirty-six or thirty-seven seconds for the duration of the 

 shock. The principal movement at Montreal did not come till 

 at least fifteen seconds after the beginning ; and the testimony 

 of the Eichmond operator shows that the violence of the shock 

 there had passed, while the tremors at Quebec were still in 

 faint continuance. Finally, it will be observed that the time 

 of occurrence stated by Mr. McCord and others— although not 

 confirmed by his comparison with any standard time-piece— 

 tends to represent the actual occurrence at Quebec to have been 

 before the empirical time of column 5 in the table, instead of 

 1"' 16* later, as shown in column 7. 



