February 8, 1900] 



NATURE 



353 



history of photography. Our readers may remember that a 

 proposal has been made, and has received some support, to 

 restore the chancel of Lacock Church, Wiltshire, as a memorial 

 to Fox Talbot. There is, at present, no other monumental 

 record of him than a short inscription on his gravestone in the 

 Lacock cemetery. Subscriptions in aid of the proposed 

 memorial, the cost of which is estimated at looo/, should be 

 sent to Mr. C. H. Talbot, The Abbey, Lacock, Chippenham, 

 or to the Fox Talbot Memorial Fund, Capital and Counties 

 Bank, Chippenham. 



The proposal to generate electricity on the Canadian side of 

 the Niagara and to sell electric power on the American 

 side, has caused a flutter of excitement among American elec- 

 tricians. The New York Electrical Review states that the 

 (juestion has been raised whether foreign-made electricity is not 

 subject to a duty of ten per cent ad valorem as an " unenu- 

 merated manufactured article." This question has produced a 

 flood of debate, and while it is purely hypothetical as yet, the 

 Merchants' Exchange of Buffalo and the Niagara Falls Power 

 Company, have gone so far as to pass resolutions opposing such 

 taxation. Those who desire discrimination in favour of home- 

 made electricity argue that electric power is a vendable and 

 valuable product of manufacture ; that it can be measured easily 

 and accurately, and that foreign-made electricity should pay duty 

 equally with foreign-made cloth or wine. Those who believe 

 in free trade in electricity point out that it is not an article, that 

 it is not valuable or sold or saleable, that it has no power to do 

 work, but only serves as a means of transmitting power, and that 

 it is utterly impossible to import it because it instantly returns 

 to its source. 



An address which Dr. H. R. Mill delivered before the Royal 

 t Geographical Society on Monday last, and which will no doubt 

 appear in due course in the Geographical Journal, should be 

 brought before the attention of every local scientific society. 

 The subject was the geography of south-west Sussex, and the 

 object was to show how the geological and topographical 

 structures, the meteorological conditions, agricultural products, 

 industries, and distribution of population are related to one 

 another. With the Ordnance Survey maps as a basis, the dis- 

 trict was subjected to minute geographical analysis, and many 

 interesting connections were brought out. (jeologically, the area 

 examined is made up of the low-lying Tertiary clays, marls, 

 sands, and pebble-beds on the coast, the chalk forming the 

 South Downs a few miles behind, and_the Greensand and Weald 

 Clay north of it. As an example of the different characteristics 

 and productive capacities of these three divisions, the following 

 taimlar statement is instructive :— 



The numbers are only approximate, but they serve to 

 exhibit the chief differences between the three areas. 

 The comparison suggests that, in this case at all events, the 

 geology of the district is the controlling influence, but Dr. Mill 

 pointed out that just as striking differences could be found in 

 areas of a single geological formation, and that it was the 

 function of geography to discover the causes, geological or 

 otherwise, which produced them. His survey was a model 



NO. r5<0, VOL. 6'] 



which should inspire others to inquire into the causes of the 

 relations between) the natural and economic conditions of their 

 own districts, and thus provide material with which to construct 

 a geography of the British Isles on scientific lines. 



A .MEMOIR on the Geology of Belford, Holy Island, and the 

 Fame Islands, by Mr. William Gunn, has just been issued by 

 the Geological Survey. The region is one with which the late 

 George Tate, of Alnwick, for long was intimately associatedi 

 until his death in 1871. The work of the Geological Survey 

 was for the most part carried on subsequently, but there 

 has unfortunately been considerable delay in the publication 

 of the memoir. It deals mainly with rocks of Lower Car- 

 boniferous age, and contains a full account of the various coal- 

 seams which have been worked in that series. Lists of 

 Carboniferous fossils are given, and there are notes on the 

 Whin Sill and on the Glacial and post-Glacial deposits. 



One of the most gigantic sanitary works of the day was 

 brought into operation at the beginning of January, when the 

 water was turned into the great drainage canal through which 

 in future the sewage of Chicago is to flow instead of into Lake 

 Michigan, the source from which the city's water supply is 

 drawn. This canal has been seven years in construction, and 

 has cost about 6,000,000/. It is 29 miles in length, and has 

 been excavated through glacial drift and solid rock, the width 

 at the bottom through the rock being 160 feet and the depth 

 22 feet. The flow of water through the canal is to be regulated 

 to 300,000 cubic feet a minute, and the volume of sewage will 

 be 4,200 feet a minute. The constant depth of water in the 

 canal is to be 22 feet, and the rate of flow is to be regulated so 

 as not to exceed one mile an hour, and it has been constructed 

 with the intention that it shall hereafter be used as a ship canal, 

 rendering navigation possible from Lake Michigan, by way 61 

 the lUinois and Mississippi rivers, to the Gulf of Mexico. The 

 watershed of this part of America is situated at the head of 

 Lake Michigan, the water from which ultimately flows down 

 the Saint Lawrence, and that to the south of the Lake by the 

 Mississippi to the Gulf of Mexico. This diversion of the water 

 and the question as to what effect it may have in lowering the 

 level of the lake and so affecting the navigation and other water 

 rights have been the subject of considerable discussion and iiv- 

 vestigation. The general opinion arrived at is that the quantity 

 of water flowing down the canal cannot lower the water in 

 Lake Michigan more than three inches. 



The passage of electricity through rarefied gases forms the 

 subject of a paper by M. E. Bouty in the Journal de Physiijire 

 for January. The author differs from Prof. J. J. Thomson's 

 view (1893) that rarefied gases behave like electrolytes, and in 

 this connection arrives by a different method at conclusions 

 agreeing with those of E. Wiedemann. According to M. Bouty 

 the conductivity of the gas is related in some manner to its 

 luminosity. In studying the electrical properties of gases we 

 have to consider (i) the dielectric equilibrium in the case of 

 fields of force of less than a certain critical intensity ; (2) the 

 modifications produced by electric discharges due to a field ex- 

 ceeding the critical intensity ; (3) the determination of the limits 

 separating the two phenomena. The last of these points forms 

 the subject of M. Bouty's present investigations. 



The Summary of the Weekly Weather Report, showing the 

 rainfall and mean temperature for the year 1899, and for thirty- 

 four years, 1S66 to 1899, has recently been published by the 

 Meteorological Council. The principal features during last 

 year have been the small amount of rain in the summer months, 

 and the high temperature that l.as persistently i-revailed in most 

 districts throughout the year. Over the British Isles generally, 



