484 
NATURE 
[SEPTEMBER 14, 1899 
Kladno collieries. The importance of the brown coal mines of 
the Teplitz district is shown by the fact that last year they pro- 
duced no less than 15,044,563 tons, and afforded employment to 
25,212 workmen. 
Tue reports which the 7z#es correspondent at St. Johns has 
received from the members of the Peary Polar expedition, who 
have returned in the steamer Windward, are disappointing. 
Grinnell Land was explored to its western extremity last 
autumn; the north remains to be explored. Next spring, 
Lieut. Peary will undertake the three years’ further prosecution 
of his quest for the pole, Captain Sverdrup, in the Fram, 
wintered fifty miles south of the Wnxdward, in latitude 79°. 
The work of the expedition has so far been unimportant. 
Tue Danish Greenland expedition, under Lieut. Amstrup, 
has returned to Mandal, after a year’s absence, and reports that 
no trace was found of Herr Andrée and his companions. A 
Reuter telegram states that the Swedish search expedition under 
Dr. Nathorst, which has just arrived at Malmo, brings af€similar 
report. The expedition explored Kaiser Franz joseph Fiord, 
on the east coast of Greenland, and there discovered a whole 
series of new inlets, the position of which was mapped. An 
especially interesting ethnographical collection relating to the 
now extinct Eskimo population was secured in that region. 
THE forty-fourth annual exhibition of the Royal Photographic 
Society, which will he held at the Gallery of the Royal Society 
of Painters in Water Colours, is now in course of preparation, 
and will be opened to the public on Monday, September 25, 
On Saturday, the 23rd, there will 
be a private view for members, exhibitors, and their friends, and 
in the evening there will be a conversazione, when the President, 
the Earl of Crawford, K.T., will receive the members and the 
other guests of the Society. 
for a period of seven weeks. 
A CONGRESS of the Royal Institute of Public Health will be 
held at Blackpool on September 21-28. 
A GouRSE of twelve free lectures on the ‘‘ Pleistocene Mam- 
malia” will be delivered by Dr. R. H. Traquair, F,R.S., in the 
Lecture Theatre of the Museum of Practical Geology, Jermyn 
Street, S.W., on Mondays, Wednesdays and Fridays, at 5 
p-m., beginning Monday, October 2, and ending Friday, 
October 27. 
THE committee appointed by the American Chemical Society 
to consider the means by which the Society could hasten the 
adoption of uniform systems of graduation, definite limits of 
accuracy, and standard methods for using all forms of measuring 
instruments employed in chemical laboratories have, we learn 
from Sczence, made the following recommendations :—(1) That 
the American Chemical Society, in a manner consistent with its 
constitution and bye-laws, ask the U.S. Office of Weights and 
Measures to adopt regulations for the verification of volumetric 
apparatus which shall be similar in purpose and scope to the 
regulations of the Kaiserliche Normal-Aichungs-Commission, 
after due consideration of the criticisms to which the latter have 
(2) That the U.S. Office of Weights and 
Measures be asked to give special consideration to the question 
of a standard temperature or temperatures to be adopted for the 
graduation of volumetric apparatus, and to obtain as far as prac- 
ticable an expression of opinion from American chemists on this 
(3) That the U.S. Office of Weights and Measures be 
to submit its regulations to the American Chemical 
Society, or a duly appointed committee thereof, for suggestions 
before final adoption by that office. (4) That the international 
(5) That the litre 
been subjected. 
point. 
asked 
kilogram be adopted as the standard mass. 
NO. 1559, VOL. 60] 
as defined by the International Committee on Weights and 
Measures be adopted; viz. the volume of the mass of a kilo- 
gram of pure water at the temperature of maximum density and 
under a pressure of 760 mm, of mercury. (6) That all density 
determinations be referred to water at its maximum density and 
under a pressure of 760 mm, of mercury. (7) That all temper- 
atures be expressed in terms of the hydrogen thermometer of the 
International Bureau of Weights and Measures. (8) That ifany 
question arise as to the interpretation of the above definitions 
the decision and standards of the U.S. Office of Standard 
Weights and Measures shall be accepted by the Society as final. 
Tue Rev. J. M. Bacon contributes to Good Words a general 
account of his experiments on the audibility of sound in air. 
It is well known that the report of the explosion of a large 
meteor may be heard over a great area, although the air at the 
point where the explosion occurs must be extremely attenuated. 
Mr. Bacon has endeavoured to imitate the meteoritic explosions 
to some extent by electrically firing Tonite cartridges suspended 
below a balloon. An ascent was made, and cartridges were 
fired at intervals, the altitude of the balloon ranging from 2000 
to 3000 feet. The reports were heard by many observers in the 
parts of London over which the balloon passed, and some in- 
teresting conclusions were derived from these observations. In 
the balloon itself careful readings were taken of the interval of 
the return of the echo from the earth, and the height the balloon 
had ascended, while the actual locality over which each cartridge 
was fired was also noted. From the results obtained, it ap- 
peared that there were no aérial echoes, as in Prof. Tyndall’s 
experiments, and that in all cases the reports in their double 
journey did not travel as quickly as the estimated speed of 
sound on the earth. ‘*In consequence of these unexpected re- 
cords,” says Mr. Bacon, ‘‘ another ascent was carried out shortly 
afterwards from the Crystal Palace when the air was in a 
totally different condition, and the altitude reached considerably 
higher. On that day a strange thing happened. The afternoon 
was an universal drizzle, and the Palace towers had their heads 
nearly shrouded in the low-lying clouds. On rising the balloon 
at once made for the west, and entering the cloud shortly re- 
appeared above in glorious sunshine. So for nearly two hours, 
when, once again descending through the clouds, we found 
ourselves still going west, but dead over the middle of the river 
below the fort at Gravesend! All unsuspected by the voyagers, 
a wind was blowing above the cloud-layer diametrically opposite 
to that on earth, but causing no impediment to sound thereby. 
The actual results obtained on the last occasion entirely con- 
firmed those of the former experiment, and differed only in the 
fact that the reports were apparently heard over a much larger 
range of country, extending well into the neighbouring counties, 
and that the reverberations following them, as heard from above, 
were yet more prolonged than before, sometimes indeed still 
lingering on after an interval of thirty seconds.” 
THE Danish Meteorological Office has just published a valu- 
able excerpt paper from its Aarbog, giving the meteorological 
means and extremes for the Faroe, Iceland and Greenland. At 
Thorshavn (Faroe) the mean monthly values of air temperature 
during twenty-five years vary from 37°°8 in January and March 
to 51°74 in July. The absolute maximum was 70°'2, and the 
minimum 11°*r. The mean annual rainfall was 63°3 inches, and 
the greatest fall in twenty-four hours 2°5 inches. For Iceland 
mean temperature values are given for nineteen years at fifteen 
stations ; the lowest yearly mean is 30°°6 at Moedrudal, and the 
highest, 41°°o at Vestmannoe, At Stykkisholm the absolute 
maximum during twenty-two years was 73°°2 in July, and the 
minimum — 14°°8 in January. The meanannual rainfall was 24°9 
inches, and the greatest fall in twenty-four hours 2'04 inches. 
For Greenland four stations are given; at the most northern 
