132 



NATURE 



[June 8, 1893 



^ 



of the-country, but shallow depressions ormed over Scandinavia 

 and the Baltic, and under their influence some slight showers 

 occurred in the extretae north and north-west. At the end of 

 the week however the anticyclone temporarily shifted somewhat 

 southwards and eastwards, thunderstorms became prevalent in 

 the north, east, and south-east, and rain fell at most stations, 

 amounting to over half an inch in the north-east of Scotland, 

 but generally speaking the amounts were slight elsewhere ; on 

 Tuesday, the 6th inst., the anticyclone again embraced the 

 whole of the southern portion of our islands. During the first 

 part of the period frost occurred on the ground in many parts of 

 England ; and although the maximum temperatures have not 

 been high generally, they have at times exceeded 70° in different 

 parts of Great Britain, but in the extreme north the highest 

 readings have generally been below 60°. The Weekly Weather 

 Heport of the 3rd inst. showed that the temperature was slightly 

 below the average in some of the wheat-producing districts, and 

 rather above it in the grazing districts. Rainfall was below the 

 mean everywhere ; the deficiency since the beginning of the 

 year ranged from 2 '3 inches in the north of Scotland to 6'0 

 inches in the west of Scotland. Bright sunshine was only above 

 the average in the west of Scotland, the south-west of England, 

 and the Channel Islands. In the latter district the duration 

 was as high as 70 per cent, of the possible amount. 



The Meteorological Council have issued the fourth volume of 

 'Hourly Means of the readings obtained from the self-recording 

 instruments at their observatories for the year 1890. The tables 

 contain hourly means or totals for periods of five days, months, 

 and for the year, and, with the exception of the wind observa- 

 tions, daily values are also given. Breaks in the hourly read- 

 ings are rare, but occur at times from failure of photography, 

 stoppage of clocks, and in the case of the wet-bulb thermometer, 

 owing to frost ; such cases, however, are carefully examined and 

 the losses can usually be made good by interpolation, with a very 

 near approach to Uccuracy. 



Sir C. Todd has published the meteorological observations 

 made at the Adelaide Observatory and other places in the col- 

 ony during the year 1890. The maximum .shade temperature 

 at Adelaide was 105° on January 18, and the minimum 34°'2 

 on July 17 ; the greatest range in 24 hours was 38'''8 on January 

 4th, and the lowest temperature on grass was 25° on July 17. 

 Throughout the colony generally very oppressive weather 

 was experienced in January and February, with heavy 

 tropical rains over northern areas, and the winter also was very 

 wet. The extraordinary rainfall (especially in the first three 

 months) was the chief feature of the year, which was the wettest 

 on record, some stations having a fall of over 100 inches. 



A CORRESPONDENT calls our attention to a peculiar pheno- 

 menon witnessed at Aboyne on the morning of May 26. 

 " Stretching along the falls of Morven and Culblean, and slightly 

 below the top of the former, was a magnificent ribbon, ex- 

 hibiting the full spectrum of colours from red to violet — in 

 fact, a perfect ' rainbow,' but without the slightest curve. The 

 sun was shining brightly in the east, while it was raining on 

 Morven, which, of course, accounts for the colours ; but I am 

 unable to account for the absence of the arch." The lowest part 

 of the ribbon showed the least refrangible colours. 



A XUMBER of experiments to determine the temperature of the 

 steam arising from a boiling salt .solution have been made from 

 time to time, but the conclusions have frequently been of acon- 

 icting character. The difficulty of arriving at trustworthy results 

 lies in the fact that the walls of the steam-chamber must be 

 above 100° C, and yet below the temperature of the solution, 

 and that, at the same time, a sufficient quantity of steam must 

 escape from the solution to ensure that these walls shall have 

 no material cooling effect upon the steam. These desiderata are 



NO. 1232, VOL. 48] 



all met by an arrangement employed by Prof. Sakurai, and 

 described in the Journal of the College of Science, Imperial 

 University, Japan, vol. vi., part i. From experiments on 

 solutions of calcium chloride, sodium nitrate, and potassium 

 nitrate, it appears that the temperature of the steam escaping 

 from a boiling solution is exactly the same as that of the solution 

 itself. 



To measure the viscosity of liquids they are let flow, under 

 given conditions ofpressure and temperature, through a capillary 

 tube, and the time of passage is determined. This is rather 

 unsuitable for very viscous liquids, such as concentrated 

 glycerine ; and Herr Brodmann has devised a method ( Wied. 

 Ann.) for determining co-efficients of friction, where these 

 exceed a thousand times that of water. The liquid flows by 

 gravity through a vertical tube from a wide vessel above, filled 

 to a certain height, into a small shallow vessel below, standing on 

 one scale of a chemical balance, the other scale being weighted 

 so that it is down. A time comes when this preponderance 

 ceases. The moment of passage of a certain mark is noted, a 

 weight is added to the weight -scale, and the process is repeated. 

 The difference of time between two of these passages corresponds, 

 after some corrections, to the direction of outflow of a quantity 

 of liquid equal in mass to the added weight. 



A NOTE in jklectricite gives the substance of a letter to :he 

 Genie Civil, in which the correspondent shows that there is a 

 difference of potential between the water and gas pipes in all 

 houses, and that if one terminal of a telephone is joined, say, 

 to the water-pipe, on lightly touching the gas-pipe with the 

 other, a crackling sound is heard in the telephone indicating 

 the passage of a current. By replacing the telephone by a 

 galvanometer, it is found that the negative pole is formed by 

 the gas-pipe, and that the galvanometer deflection is permanent 

 and constant in amount during several months, though there is 

 a slight diurnal variation. The author attributes these currents 

 to a slow chemical change in the pipes, which thus form the 

 plates of a battery. However, these observations suggested 

 that the pipes must be fairly well insulated from each other, 

 and might act as conductors for telephonic communication, iind 

 he has succeeded in carrying on a conversation, without any other 

 connecting conductor between two houses at a distance of a 

 hundred metres apart. In this experiment the microphone, 

 without any induction coil, was joined to three bichromate cells. 

 It is very easy to see if the experiment will succeed, as it is only 

 necessary to set a small induction coil to work, joining its ter- 

 minals to the water and gas-pipes, then in all neighbouring 

 houses in which, on joining a telephone to the pipes, the sound 

 of the coil is heard communication is good. Even if speech 

 cannot be satisfactorily transmitted, it would be possible to 

 communicate by the ordinary Morse signals. 



A HIGHLY sensitive manometer, suitable for measuring 

 small variations of high pressures, is described by M. Villard in 

 No. 21 of the Comples Rendus. It consists of a U-tube one or 

 two mm. in diameter and about 20 cm. long, one end of 

 which leads into a closed glass cylinder about 5° ^l- '^oxa. in 

 section and 8 or 10 cm. long or longer, according to the 

 degree of sensibility required. The other end opens into 

 another wide tube ending in a narrower portion, which may be 

 bent back. A narrow copper tube fixed inside this portion by 

 about 3 cm. of marine glue forms a most efficient mouthpiece 

 and offers an almost indefinitely large resistance to the passage 

 of gaseous matter. Enough mercury is contained in the 

 U-tube to fill one of its branches. The filling is to a great 

 extent self-acting. The mouthpiece need only be coimected to 

 a compressed gas reservoir. The gas bubbles up through the 

 narrow tube and fills the cylinder at the pressure required. A 

 slight expansion subsequently enables the mercury to reenter 



