1042* Memoir on Indian Earthquakes. [No. 144. 



menon, in many houses a very distinct motion was communicated to 

 the oil in the wall-shades ; the girandoles and lamps were seen to swing, 

 and even the mirrors (such as were fastened at the upper extremity 

 with a cord) were observed to vibrate towards the wall. In a room on 

 the central floor of one of the turrets of the lower Orphan School at 

 Howrah, (which is a very old and infirm building,) the force of the un- 

 dulations was so considerable, that a couch on which a person happen- 

 ed to be reclining was moved on its castors at the first shock to the 

 distance of nearly a foot from its original position close to the wall, 

 and was again thrown back to its place by the returning succession. 

 To some persons the vibration appeared to be accompanied by a noise 

 which they describe as resembling the sound of muffled bells. 



" Reports from various stations in the lower parts of Bengal, as 

 far up as Moorshedabad, mention the occurrence of a similar pheno- 

 menon, nearly about the same hour. By a letter from Ramnagur, the 

 vibration is stated to have been felt there at half-past seven, and to 

 have continued for an unusually long time." 



No farther notice of Earthquakes in the Delta of the Ganges occurs 

 until the year 1829, when on the 18th September, at a little past 7 

 a. m., two shocks which are described as having been " very strong," 

 were experienced at Calcutta. I have found only a very brief notice 

 of these shocks, and beyond the fact, that the movement of the earth 

 during their continuance was vertical, or " up and down," I find nothing 

 else of interest recorded. 



Another long interval of quiescence occurs, and it is not until the 

 11th November 1842, that we have any other Earthquakes at Calcutta, 

 or in its vicinity. On that day at nearly half-past 9 p. m., an Earth- 

 quake was experienced throughout the Delta of the Ganges, which from 

 the published accounts would appear to have been the most severe felt 

 within the previous twenty-five years. All particulars connected with 

 this shock have been given in ample detail in the first part of this 

 memoir, and I need not therefore dwell long upon it here. It was a 

 shock evidently originating within the Gangetic Delta, not communi- 

 cated from any other tract : it was felt very feebly indeed at the north- 

 ern extremity of the Arracan region, and not at all, that I am aware 

 of, at any of our stations along that coast: its intensity diminished 

 perceptibly in its course from the vicinity of Calcutta, in all directions, 

 and even had we no other grounds for establishing the Delta of the 

 Ganges as an independent Earthquake tract, this shock alone would I 

 think be sufficient to warrant our doing so. The point where the dis- 

 turbing forces act is in the immediate vicinity of Calcutta, since it is 

 there that the intensity of the recorded shocks has always been greatest. 

 It is possible, however, that had we equally good intelligence from 

 other localities in the Delta, it would appear that the vicinity of 

 Calcutta was not the only centre of disturbance, and as observers and 

 observations are multiplied, a wider range may perhaps be given to the 

 forces in aetion. 



