_Anomalies in the above Measurements._--If the movements of the ground followed the law of simple harmonic motion, any two of the four elements (period, amplitude, maximum velocity, and maximum acceleration) would suffice to determine the others (p. 4). Applying the usual formulæ to the quantities obtained at Gauhati--namely, 8 feet per second for the maximum velocity and 12 feet per second per second for the maximum acceleration, it follows that the amplitude would be 5 feet and the period 4 seconds--values, which are evidently inadmissible. Or, taking the maximum vertical component at 32 feet per second per second, the corresponding values would be 2 feet and 1-1/2 seconds, that of the amplitude being still too great. Again, at Rambrai, the maximum velocity was found to exceed 16 feet per second. The other elements are unknown, but, if the amplitude were one foot, Mr. Oldham shows that the maximum acceleration would be 256 feet per second per second; or, taking the amplitude at the impossible amount of two feet, that the maximum acceleration would be 128 feet per second per second. It follows, therefore, that only part of the high velocities at Rambrai and elsewhere can be due to the elastic waves provoked by the initial disturbances. The remaining portion must be attributed to a bodily displacement of the earth's crust within the epicentral area--a displacement of which the fault-scarps and other distortions of that region furnish ample evidence. SOUND-PHENOMENA. In the epicentral area, the sound that accompanied the earthquake was remarkable for its extraordinary loudness. At Shillong, the crash of houses falling within thirty yards was completely drowned by the roar of the earthquake. The sound was generally compared to distant thunder, the passage of a train or cart, etc.; but, whatever the type may be, it always implies a sound of deep pitch, close to the lower limit of audibility--a continuous rumbling or rattling noise, as a rule gradually becoming louder and then dying away. There was the usual conflict in the evidence of different observers due to the depth of the sound. In Calcutta, which lies well within the sound-area, some persons asserted that they heard a rumbling noise; others were positive that the only noise was that caused by falling buildings and furniture. Some, again, noticed that the shock was preceded by a loud roar; while others were certain that there was no sound of any kind until the earthquake had become severe.