ON NEW ENGLAND EARTHQUAKES. 23 



October 20, 1870, at ll*" 25' a distinct vibration was felt from New Brunswick to 

 Iowa. The duration and direction of the shock have been variously stated, and 

 illustrate the difficulty of seismic observations, without instruments. By my own obser- 

 vations, the duration was more than a minute. I was seated at a very solid desk, and 

 when tlie shock commenced was writing, which became impossible, and on looking at my 

 watch, I found that the vibration continued sensibly 43", but died away so gradually that 

 I could not distinguish it from possible jar from passing teams. No noise could be ob- 

 served. All persons familiar with earthquakes, know the peculiar feeling of direction, 

 almost indescribable, and very various ; sometimes like a train of cars passing under a 

 bridge, but so distinct that the noise or vibration comes from a certain direction. In the 

 present case, the shock, although slight, was sufficient to move a door of my desk that 

 happened to be open, its plane in a south-south-east direction, through an arc of 4°-6° 

 repeatedly and rapidly, indicating a course of approximately, north-north-east to south- 

 south-west. An observer in the same neighborhood thought the oscillation was from 

 south-south-west to north-north-east, and the duration about 28". 



Many persons in Boston felt a slight nausea, while others did not feel the shock at all. 

 It was felt less on the new-made lands than in the ancient part of the city. In Canada 

 the eifects were more severe and walls are reported cracked, and chimneys overthrown. 

 A telegraph operator in Quebec was in the act of enquiring about the earthquake at 

 Montreal, when it was felt at the latter place. 



At Portland, Maine, glass was broken ; the shock was felt more perceptibly on the 

 ■wharves. The telegi'aph operator at Bangor reported the shock about 2" before it was 

 felt at Portland. About three hundred feet of the Ogdensburg Railroad, sixteen miles 

 from the city, settled ten feet at the time of the earthquake. 



At Bath the vibrations seemed east and west, and their dui'ation 15". 



At Bowdoin College, Brunswick, a chimney was broken ; the direction seemed north- 

 east and south-west, and the duration 30"- 40". 



Augusta, two shocks were noticed ; the duration was 25". 



Lewiston, bricks were thrown from several chimneys, and the shock lasted about 30". 



Burlington, Vermont, a distinct shock at ll"" 26' A.M. There were i-egular vibrations 

 from south to north, lasting in all about 15". 



Newburyport, Massachusetts, a slight jar was felt, which was immediately followed by 

 a heavy rumbling lasting 30", jarring buildings and ringing doorbells. It seemed to pass 

 off in a south-westerly direction. 



At Cambridge, Massachusetts, Professor Winlock, of the Observatory, considered the 

 direction of the vibrations about 10° north of east, but he judged only from the appear- 

 ance of the sides of a vessel containing milk. 



At Boston, an observer gives the time of the cessation of the shock at ll"" 25' 37'' Cam- 

 bridge mean time. 



At Springfield, three distinct shocks were noticed, of which the last was the severest, 

 lasting 7"- 8". 



At New Haven, Connecticut, and other places, there were two distinct series of vibra- 

 tions. The shock commenced at ll"" 19' 45" New Haven mean time, or 1' 45" after it 

 reached Boston, apparently. It lasted ten seconds, and the individual half vibration, 

 lasted about two-thirds of a second ; after an interval of five seconds there was another 



