86 4 



THE POPULAR SCIENCE MONTHLY. 



ments ; that officers affected in their vision 

 be given shore employment ; and that certain 

 specified improvements be introduced into 

 the method of testing for defects of vision. 



The way changes are produced in the 

 configuration of the country in a region of 

 lakes by the action of the water is illustrated 

 in a recent lecture by R. H. Mill. Taking- 

 certain English and Scotch lakes, Loch Tay 

 has been gradually silted up during the last 

 thirty years ; a stony peninsula is building 

 up at the foot of Ullswater ; the rush of the 

 waves is slowly eating away the eastern 

 shore of Windermere; the affluent rivers are 

 filling Haweswater with stones and rubbish, 

 and a delta has been formed which nearly 

 cuts the lake in two a process which has 

 been completed in certain lakes that are 

 specified. The famous floating island of 

 Derwentwater is probably a piece of the 

 moat of waterweed that covers the floor of 

 some parts of the lake, raised to the surface 

 by the gas given off by its own decompo- 

 sition. 



Thoreau says in his Early Spring in 

 Massachusetts, speaking of a class of books 

 which have not yet gone out of fashion : 

 " A good book is not made in the cheap and 

 offhand manner of many of our scientific re- 

 ports, ushered in by the message of the 

 President communicating it to Congress, and 

 the order of Congress that many thousand 

 copies be printed with the letters of instruc- 

 tion from the Secretary of the Interior (or 

 rather exterior), the bulk of the book being 

 a journal of a picnic or sporting expedition 

 by a brevet lieutenant-colonel, illustrated by 

 photographs of the traveler's footsteps 

 across the plains, and an admirable engrav- 

 ing of his native village as it appeared on his 

 leaving it, and followed by an appendix on 

 the paleontology of the route by a distin- 

 guished savant who was not there ; the last 

 illustrated by very finely executed engrav- 

 ings of some old broken shells picked up on 

 the road." 



Of a limited study of dietaries, mostly 

 in New England, acknowledged to be imper- 

 fect, the results, as summarized by Prof. W. 

 0. Atwater, decidedly confirm the general 

 impression of hygienists that our diet is one- 

 sided and that we eat too much. The food 

 which we actually eat, leaving out of account 

 that which we throw away, has relatively too 

 little protein and too much fat, starch, and 

 sugar. This is due partly to our large con- 

 sumption of sugar and partly to our use of 

 fat meats. The rejection of so much of the 

 fat of meat at the market and on our plates 

 at the table is not mere willfulness. It is in 

 obedience to Nature's protest against a one- 

 sided and excessive diet. How much harm 

 is done to health by our one-sided and excess- 

 ive diet no one can say. Physicians tell us 

 that it is very great. 



A successful demonstration was given 

 in April to a meeting of medical men in 

 London by Mr. S. Schontheil, of the most 

 modern and scientific method of training the 

 deaf and dumb so as to enable them to use 

 articulate speech and give them a full com- 

 mand of language. Several pupils were in- 

 troduced who were subjected, with highly 

 satisfactory results, to exercises in pronun- 

 ciation, lip-reading, dictation, recitation, read- 

 ing, and answering miscellaneous questions. 



It is now generally recognized in Great 

 Britain, ex-President Teall, of the Geological 

 Section of the British Association, says, that 

 there is no important difference in structure 

 or composition between the rhyolites, ande- 

 sites, and basalts of the Palaeozoic and of the 

 Tertiary periods. Identity of structure and 

 composition in this case implies identity in 

 the physical conditions under which the 

 rocks were produced. Hence we may sum 

 up the case of the bearing of volcanic rocks 

 on the theory that, so long as observations 

 are confined to a limited area, doubts may 

 arise as to the truth of the uniformitarian 

 view, but these doubts gradually fall away as 

 the area of observations is extended. There 

 are still some outstanding difficulties, but, as 

 many similar ones have been overcome in the 

 past, it is improbable that those that remain 

 will prove formidable. 



OBITUARY NOTES. 



The death of Prof. Valentine Ball, of 

 Dublin, is a serious loss to the scientific 

 circles of that town. He contributed much 

 to the literature on precious stones, and pub- 

 lished several books of travels. Although 

 of fine physique, he died at the age of only 

 fifty-one. 



The death is announced of Prof. Baillon, 

 Director of the Botanical Laboratory of the 

 faculty of medicine at the Sorbonne. He 

 was one of the most distinguished of the 

 Erench botanists and a very prolific writer. 

 He was born at Calais, November 30, 1827. 



Dr. Friedrich Tietjen died on June 21, 

 1895. He was Professor of Astronomy at 

 Berlin University and editor of the Astrono- 

 mischen Jahrbuch. He was born in 1834. 

 His most important labors lie in the region 

 of astronomical computation. 



Dr. FRiEnRicn Wilhelm Gustav Sporer, 

 chief observer in the Astrophysical Observa- 

 tory at Potsdam, died on the 7th of July of 

 heart disease. He was born in Berlin, Oc- 

 tober 23, 1822. He took his degree from 

 the Berlin University in 1843. He did a 

 large amount of valuable astronomical work, 

 being especially interested in sun spots, his 

 work on these making his name known to 

 the scientific world. 



