198 



NATURE 



[January 2, 1896 



Last winter the whole of the lake was frozen over, for [the 

 first time since 1814. One fine afternoon, when the air was 

 still, I was skating in the neighbourhood of Shande's Castle, 

 when these mystical guns boomed forth their reports every five 

 or six minutes. On the last day of the skating, when thousands 

 of people from Belfast and elsewhere were assembled in Antrim 

 Bay, there were two fearful boomings, that startled every one 

 near me. They seemed to think some dreadful catastrophe 

 had occurred, as the sounds appeared to proceed from not more 

 than half a mile away. I never before heard them so near. 

 The ice in Antrim Bay remained as it was, but I afterwards 

 learned that it was then breaking up six miles away, but with no 

 alarming sounds. Last February, when the ice of Lough Neagh 

 was breaking up, a strange occurrence took place at Ardmore. 

 A great ridge of ice, a mile and a half long, and 10 feet high, 

 and 15 feet at the base, was formed along the shore during 

 three days. There was a dead calm at the time, so that the 

 ice was not thrown up by the waves. The ice along this part 

 of the shore, for a third of a mile out, was intact ; the ridge 

 must have consisted of ice brought from a considerable distance, 

 and forced under the shore ice, which was raised every few 

 yards into small archways, and then shot out from beneath to 

 the height previously specified. The pieces of ice were from 

 half a*" yard square to bits of an ounce in weight, all mingled 

 in the huge mass. Such a sight had not occurred since 18 14, 

 when, as I learned from a member of my congregation, who 

 had seen it in that year, the water of the lake could not be seen 



tide was quite out. So the " very suggestive coincidence" be- 

 tween the Bays of Bengal and Morcambe loses point ! Further, 

 it is seldom that the waves break at all, or even " curl over " on' 

 the shores of Morecambe Bay, where it is flat ; but the water 

 simply overflows the banks of the channel of the river Kent,, 

 whose course is followed by the tidal wave. There are lime- 

 stone quarries at or near Arnside, Silverdale, Warton, Carnforth 

 and Berwick. O. Firth. 



Hawthorn House, Baildon, Yorks. 



Charles Darwin, in his " Naturalist's Voyage round the 

 World" (new edition, 1890, p. 346), describes some curious 

 earth-sounds heard in Northern Chile ; he also gives references 

 to Seetzen and Ehrenberg as authorities for the occurrence of 

 similar sounds on Mount Sinai, near the Red Sea. 



It is stated that the phenomenon is caused by sand in 

 motion. William Stoney. 



Civil Service Club, Capetown, December 4, 1895. 



The Merjelen Lake. 



The annexed illustration is reproduced from a photograph 

 taken by me on August 16, 1890, when the lake was empty. 

 How long it had been so, or how long it continued, I cannot 

 say. So far as my memory serves me, there was no water what- 

 ever in it, and I distinctly recollect noticing the icebergs lying 



from the shore-road on account of this icy obstacle. There are 

 currents in Lough Neagh, but I am not aware of any strong 

 enough to produce such an effect. W. S. Smith. 



Postcript. — ^In my former letter, an extract was given from 

 Major Head's work, published some fifty years ago, and on again 

 referring to it, I find the following passage: — "The cold in- 

 creased to a very low temperature, the effect of which upon the 

 extended sheet of ice that covered the bay, was remarkable. It 

 cracked and split from one end to the other with a noise that 

 might have been mistaken for distant artillery." This explains 

 the sound to some extent in winter, but Mr. Smith says that the 

 cannon-like sounds may be heard at any time of the year. This 

 requires explanation. C. T. 



In your issue of November 14 last. Prof. McKenny Hughes 

 appears to favour the idea that the curious sounds heard near the 

 shores of Morecambe Bay, are due to the waves breaking ' ' on 

 the long, flat shore " thereof. I heard these sounds on Saturday, 

 December 21, and could trace them to blasting operations near 

 Carnforth. I heard them between 9.15 and 9.30 a.m., and the 



NO. 1366. VOL. 53] 



high and dry on the bottom. I walked along what had been the 

 margin of the lake on my way to the Aletsch glacier, which I 

 ascended to the Concordia Hut. I hope the photograph may be 

 of interest to Dr. Preller, and others who know the lake. 



Greenwood Pim. 

 Co. Dublin, December 19, 1895. 



The Metric System. 



I NOTE a call from Mr. John W. Evans, in Nature for 

 December 5, 1895, for the use of the metric system in meteoro- 

 logy. If this means the substitution of the metre for the yard, 

 there can be no serious objection except this. In meteorological 

 studies 'Oi" of air pressure is an extremely convenient limit, and 

 in most inquiries only two figures are needed. On the other 

 hand a millimetre ("04 inch) is altogether too large a limit, and 

 one-tenth m.m. is too small. The labour of writing, averaging, 

 and studying with the metric scale will be at least one-third 

 greater than with the common inch scale to the same degree of 

 accuracy. It is a very great pity that the French, in looking 



