SCIENTIFIC news: 



[Jan. 6, 1888. 



LAKE-BALLS IN SOUTH UIST. 



ALL who delight in knowing about any new curiosity 

 will be pleased to be told of the lake-balls found in 

 the Island of South Uist. It is a remarkable fact that 

 the loch of lower Kildonan in that small island of the 

 Western Hebrides is the only loch in Scotland where the 

 balls are to be found. In that loch, however, they are 

 to be met with at the bottom in great numbers. Mr. 

 G. W. W. Barclay has been lately examining these re- 

 markable balls, and he has been told that they have 

 existed there from time immemorial. No books on the 

 Hebrides make any mention of them ; and the inhabitants 

 could give him no information on the subject. They are 

 also found in several European countries; but, as we men- 

 tioned above, nowhere else in Scotland. The question 

 naturally arises, how did these curiosities reach South 

 Uist ? The loch in which the balls are found is an 

 irregular sheet of water, less than half a mile across 

 in any direction. It lies near the west coast of the island, 

 and is connected with the sea by the so-called " river " 

 Boglass, which is a large ditch, eight feet broad and 

 three quarters of a mile in length. The whole of the 

 west side of the island is very flat, and Loch Kildonan 

 lies only a few feet above the sea level. Except where 

 the tide from the Boglass enters, the water of the loch 

 is fresh. The tide, however, makes this part brackish; 

 and it is in this place that the balls are found. Here 

 the loch is quite shallow, and the bottom seems to be 

 a mixture of sand and mud. The balls lie in a depth 

 of two to three feet, and cover areas of many square 

 yards, showing conspicuously by their dark colour 

 against the light sandy bottom. They vary in size 

 from about a quarter of an inch to four inches in dia- 

 meter. Sometimes a complete ball is found inside a 

 larger one. The balls are for the most part spherical, 

 or nearly so. Mr. Barclay was told by a clergyman, who 

 was fishing on the loch, that he had found one ball " as 

 big as a hat." A microscopic examination of the balls 

 shows that they are composed of a filamentous alga. In 

 the interior of the ball are numerous diatoms, which 

 in another form have been found of so great value in 

 the deposits of the neighbouring island of Skye for the 

 manufacture of ultra-marine and dynamite. Professor 

 Fischer, of Bern, has been able to distinguish these 

 algoid lake-balls according to the structure of the fila- 

 ments and the size of the balls. They are found in 

 Sweden, Germany, Austria, and Italy. He got one in 

 Ellesmere, in England, with filaments longer and more 

 silky than the specimens in South Uist, and of a .some- 

 what different shade of green. There is now much 

 speculation on the part of botanists and geologists as to 

 how these lake-balls got into that remote western island 

 of Scotland. Certainly it is one of the strangest among 

 modern curiosities. 



The Purity of Salt. — The fact is probably not generally 

 known that the salt mountains of Nevada, the salt island 

 in Louisiana, as well as various other deposits of salt 

 in different parts of the world, are almost absolutely pure 

 chloride of sodium. It appears that of 22 '28 per cent, of 

 salts found in Great Salt Lake, 20'i9 per cent, is pure 

 chloride of sodium, and yet many of the streams running 

 into the lake contain much larger quantities of other salts, 

 some of the water being so heavily charged with nitrates 

 and sulphates of soda and potash as to be unfit for 

 animals to drink. 



ABSTRACTS of PAPERS, LECTURES, etc. 



THE ROYAL SOCIETY. 

 At a meeting of the Royal Society on the 8th December, 

 Mr. G. J. Symons read a paper " On the Detonating 

 Bolide of November 20th, 1887." Mr. Symons said that 

 shortly after November 20th, it was generally reported 

 that an earthquake shock had been felt in the South 

 Midland counties of England, and he began to collect 

 and examine the facts. It appeared that the records 

 from Oxfordshire, and the western stations generally, 

 indicated that much louder sounds were heard there than 

 at the eastern stations — e.g., Essex and Cambridge. He 

 thought that, although the phenomenon had been almost 

 universally ascribed to an earthquake, it was more 

 probably due to a explosive bolide, and on receiving 

 from one of the local scientific societies a request for 

 assistance in tracing the shock, he suggested the 

 alternative explanation. Mr. Fordham had subsequently 

 written to say that he had already found one person who 

 saw the meteor from Hertford, which he described as 

 " a brilliantly luminous body travelling across the sky 

 from north-east to west." It was further stated that a 

 portion of the meteor was seen to fall from the main 

 body. Considering that the morning, as shown by the 

 records of the Royal Meteorological Society, was both 

 misty and cloudy, and that at time at which it appeared, 

 Sunday morning, 8- 20 a.m., there would be broad 

 daylight, it was improbable that ^ many persons saw it. 

 Judging by the description of the noise, as well as the 

 path roughly indicated by the Hertford observation, it 

 seemed likely that it exploded over the south of 

 Oxfordshire ; but further details were much wanted. 

 The meteor must apparently have been very large, as 

 the explosion was heard or felt over an area of upwards 

 of 2,000 square miles, the area being eighty-four miles 

 in length, from about south-west to north-east — i.e., from 

 the confines of Wiltshire to Newmarket, Cambridgeshire, 

 and of an average breadth of about twenty-five miles. 



ROYAL METEOROLOGICAL SOCIETY. 

 At the opening meeting, Mr. W. Ellis, F.R.A.S., presi- 

 dent, in the chair, the following papers were read : — 



(i) The Use of the Spectroscope as a Hygrometer Sim- 

 plified and Explained," by Mr. F. W. Cory. The object 

 of this paper was to suggest as simple a way as possible 

 of using the spectroscope as a hygrometer in order to 

 facilitate its introduction amongst observers as a stan- 

 dard meteorological instrument. The best form of hy- 

 grospectroscope as a recognised standard for the purpose 

 of investigating and scrutinising the changes of the three 

 parts of the spectrum mentioned, is that originally termed 

 by Mr. Rand Capron " The Rainband Spectroscope." It 

 ought to have a fixed slit, and in addition a milled wheel 

 at the side for the easier adjustment of the focus. The 

 author concluded by giving a set of hints to observers for 

 taking weather observations with a pocket spectroscope. 



(2) Rainfall on and around Table Mountain, Cape- 

 town, Cape Colony,"by Mr. J. G.Gamble,M.A. Theauthor 

 called attention to the great and, in some respects, pecu- 

 liar differences that exist between the quantity of rain 

 that is registered on and around Table Mountain. 



(3) " On the Cause of Diurnal Oscillation of the 

 barometer," by Mr. R. Lawson, LL.D. The object of 

 this paper was to show that the diurnal oscillation of the 

 barometer is mainly due to the combination of the earth's 

 rotation with its orbital motion. 



