360 THE POPULAR SCIENCE MONTHLY. 



blasts, and that after three o'clock its motion was not interfered with, 

 would indicate that more violent disturbances took place before than 

 after that houi\ A smaller anemometer of Robinson's model was torn 

 from its fastenings between two and three o'clock, and so completely 

 demolished that no record even of the work which it had already 

 done could be obtained. This is much to be regretted, as otherwise 

 a means of verifying the extraordinary velocity registered by the 

 anemograph would have existed. Concerning the latter it should be 

 said that, regarding the smaller anemometer as a standard, it has been 

 found upon examination to somewhat ovei'-estimate the velocity of 

 very high winds, and to under-estimate those of low speed. At the 

 same time it can not be positively stated which of the two instruments 

 was in error. 



A continuous record of the direction of the wind is kept. Upon 

 examining this it is found that, during the whole of the period consid- 

 ered, the direction varied between north and west. Up to 1 a, m., of 

 the 4th, the wind was steadily from the north-northwest. From that 

 hour until -5 a. m., its fluctuations were confined between northwest 

 and west. A decided change in direction seems to have taken place 

 between the hours of two and three o'clock. 



The early part of the storm was accompanied by an unusually heavy 

 fall of rain. The violence of the wind prevented the reading of the 

 rain-gauges during the night, but when emptied at 7 a. m. they showed 

 a total of 4'66 inches, nearly all of whicb must have fallen during at 

 most two or three hours. 



It may be interesting to make some comparisons between the vio- 

 lence of this storm and that which was undoubtedly the immediate 

 cause of the destruction of the Tay Bridge, on the evening of Decem- 

 ber 28, 1879. Unfortunately, it does not appear that any very exact 

 or reliable observations of the velocity of the wind on that occasion 

 were made ; but an approximate measure of it may be obtained from 

 the testimony of several of the witnesses, who were men of consider- 

 able experience in the observation and estimation of high winds. The 

 following selections from the " Times " report of the Board of Trade 

 inquiry are of interest in this connection. Captain Scott, R. N., who 

 was superintendent of a training-ship stationed in the Tay, testifies 

 that his barometer fell from 29'60 inches at noon to 29 inches at seven 

 o'clock that being the lowest point reached. Also, that, in the navy, 

 storms were described by numbers from 1 to 12, 12 being the maxi- 

 mum. Upon that scale he would describe this storm in the Tay as 

 from 10 to 11. He had on rare occasions in China and the West Indies 

 rated storms as high as 12. 



Admiral William Heriot Maitland Dougal, who had resided at the 

 mouth of the Tay continuously for twenty-nine years, stated that his 

 barometer fell from 29*40 inches to 28*80 inches. The difference be- 

 tween these and the previous barometric heights is easily explained by 



