February 22, 1900] 



NA TURE 



399 



diminution of activity which has occurred: The Fountain 

 Geyser, which was such a favourite that the Fountain Hotel 

 was situated at that spot, is now wholly extinct, and a very 

 inferior substitute named the Dewey Geyser has taken its place. 

 The Cascade Geyser, another favourite because of the frequency 

 of its eruptions (about every fifteen minutes), has dropped to an 

 eruption interval of once every twenty-four hours. The Grand 

 Geyser, which used to burst out once a day, was only active 

 three or four times the past season. The Beehive Geyser, active 

 in 1895, is supposed to be wholly extinct. Old Faithful seems 

 as fine as ever, but the interval of eruption is now about seventy- 

 five or eighty minutes instead of once an hour. If it is possible 

 to judge fairly of such matters, there seems to be increasing 

 activity in the ebullition of the water in that greatest of geysers, 

 the Excelsior, which leads to a feeble hope that it may possibly 

 be rejuvenated yet once again. An apparent increase in the 

 activity of the Mud Geyser has also been remarked ; but in soite 

 of these cases, on the whole it appears that a distinct decline of 

 aetivity ip taking place. 



Thk Meteorological Council have just issued a discussion of 

 the diurnal range of rain at the seven observatories in connec- 

 tion with the Meteorological Office, for the years 1871-90. The 

 tables show, inter alia: (i) the total monthly and yearly 

 amounts for each hour ; (2) the average hourly rainfall for one 

 day in each quarter, and for the whole year ; and (3) the fre- 

 quency of its occurrence for each hour, expressed in percent- 

 ages ; and the tables are accompanied by diagrams. England 

 is represented by three stations— Falmouth, Stonyhurst and 

 Kew ; Scotland by two — Glasgow and Aberdeen ; and Ireland 

 by two— Valencia and Armagh. The year, as a whole, does not 

 exhibit any well-defined distribution of quantity. The western 

 observatories show that the heaviest rains occur in the early 

 morning, and that the least rain falls in the early afternoon ; 

 while the inland and eastern observatories show that the heaviest 

 rains fall in the afternoon. The frequency with which rain 

 falls at the different hours of the day gives more regular results 

 than can be obtained from the hourly distribution. The general 

 conclusion drawn by Dr. R. H. Scott, who has carried out this 

 useful investigation, is that everywhere in the British Islands 

 the forenoon hours, from about ten o'clock, are drier than the 

 rest of the day, and that although the temperature has not then 

 nearly reached its maximum, invalids would be less likely to 

 get wet if they went out in the morning. In the neighbourhood 

 of London, however, there is very little evidence at any season 

 of the year of a maximum frequency of rain. 



A DESCRIPTION of an aluminium cable used by the Hartford 

 Electric Light Company as a three-phase line, to convey the 

 current over a distance of more than eleven miles, is given in 

 the New York Electrical Review. This is another case in 

 which aluminium has been successfully used as an electrical 

 conductor. The trial stage is now passed, and aluminium con- 

 ductors have been proved to stand the test of pr&ctical working 

 under many different conditions, and for continued periods of 

 time. The high price of copper is responsible for the increased 

 use of aluminium as a substitute for it. The difference in 

 specific gravities between copper and aluminium is as i : 3.33 

 and with a conductivity of 60 per cent, that of copper, there is 

 an actual difference in weight between an aluminium and 

 a copper line of about 50 per cent. This fact was very notice- 

 able in putting up the Hartford wire, it being very much more 

 readily handled in the stringing. An objection has been raised 

 to the use of aluminium from the fact that the diameter is I 

 necessarily increased. This is true, but in ordinary circum- 

 stances an increase of 20 per cent, in the diameter of a con- 

 ductor is not of great importance, and the objection applies only 

 NO. 1582, VOL. 61] 



to conductors that are carried in <Jucts or conduits where space 

 is necessarily limited. Official tests have been made under the 

 direction of the Hartford Electric Light Company's experts, and 

 the guarantees have been fully equalled, and in some cases 

 exceeded. The line has worked perfectly from the time the 

 generators were started, and has been accepted by the 

 company. Some of the American plants equipped with 

 aluminium wire are carrying much higher voltages than this 

 particular line, which was constructed for 20,000 volts. 



A USEFUL paper by Mr. H. N. Dickson, entitled "The 

 mean temperature of the surface waters of the sea round the 

 British coasts, and its relation to the mean temperature of the 

 air," was recently communicated to the Royal Meteorological 

 Society {Quarterly Journal, vol. xxv. No. 112). The paper 

 was based on observations taken during eighteen years, 1880-97, 

 at the instance of the Meteorological Council, with the co- 

 operation of the Coast Guard and the various Lighthouse 

 authorities. The observations, which were taken about sun- 

 rise and 4h. p.m., have been carefully sifted by Mr. Dickson, and 

 the monthly and yearly averages calculated, tabulated, and 

 plotted on small charts. The extent of the daily range appears- 

 to depend on local conditions, such as the speed and duration of 

 tidal streams, the extent of shallow water, &c. The stations on 

 the west coast give a daily mean range for the year of o°7, 

 those in the North and Irish Seas give a daily range of o°*8. 

 With regard to the yearly distribution of temperature, the 

 average at the entrance to the English Channel is about 54°, o»v 

 the south-west of Ireland 52°. The mean of 49° persists along 

 the north coast of Ireland and the west coast of Scotland to- 

 Stornoway. After leaving the Straits of Dover the mean falls 

 to 50° off Suffolk and Norfolk, declining to 48° off the coast of 

 Northumberland, and to 47° at the Orkneys and Shetlands. A 

 comparison of the mean annual temperatures of air and sea 

 shows that the mean excess of sea over air never exceeds 2° j. 

 a difference of l°7 is only reached or exceeded off the west 

 coast of Ireland, and the south-east coast of England. On the 

 south coast of Ireland, south-west of England and the extreme 

 north of Scotland, the difference is about l' ; in the Irish Sea 

 and the east coast of Scotland about o°"5, and on the east coas 

 of England still less. One important conclusion drawn by the 

 author is that the mere presence of Atlantic water is more 

 effective in depressing the summer temperature than -in raising, 

 that of the winter months. Apart from the value of the paper 

 as a contribution to climatology, it will be of special import- 

 ance in investigations connected with questions of fisheries. 



In the Physical Review for December 1899, Mr. E. H. 

 Loomis describes experiments on the freezing points of solutions, 

 conducted with the object of testing the validity of the van 't 

 Hofl constant for dilute aqueous solutions of non-electrolytesw 

 The method of determining the freezing points of dilute 

 solutions is one introduced by the author in 1893, and has beei> 

 used to find the molecular depressions of a large number of non- 

 electrolytes in aqueous solution, and it is found that the van 't 

 Hoff constant is exactly verified in all cases examined, except 

 methyl-alcohol, ethyl-alcohol and ether. The experimental 

 value is found to be I '86. 



A REPORT on units of heat, drawn up by E. Warburg for the 

 Naturforscherversammiung in Munich of September last, has 

 been reprinted by Johann Ambrosius Earth, of Leipzig. The 

 report deals with the absolute units, the erg and joule, and 

 their relations with practical units, viz. the "calories" in which 

 water at o" and at 1 5° are taken respectively as standards, and 

 the mean water-calorie between o" and 100", also the temperature 

 variations of the specific heat of water, especially in the neigh- 

 bourhood of its maximum. 



