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ee 
SEPTEMBER 18, 1913] 
calendar by the Protestants in Switzerland. Practical 
convenience forced them to follow the. Gregorian 
calendar in the main, though not until the end of 
the seventeenth century, and even then one difference 
was maintained. This arose from basing the calcula- 
tion of the Easter full moon on the Rudolfine Tables 
instead of the Gregorian Epact. The first discrepancy 
occurred in the year 1724, when the Gregorian full 
moon fell on Sunday, April 9, while the Tables gave 
the day preceding. The question was referred for 
decision to the Protestant Conference at Ratisbon early 
in 1723, and the Basel authorities sought the advice 
of John Bernoulli. The replies are reproduced in full. 
In the result Easter was celebrated by Catholics and 
Protestants on successive Sundays in 1724 and again 
in 1744. Agreement was finally brought about by 
an order of Frederic the Great in 1776 on the basis of 
the Gregorian calendar. The desirability of a fixed 
Easter has been commonly felt from the time of the 
Gregorian reform, and it was the last act of Father 
Denza, late director of the Vatican Observatory, to 
prepare a memorandum on the subject for Pope Leo 
XIII. His proposal was to adopt the third Sunday 
following the vernal equinox, which would limit Easter 
between April 4 and 11. 
Tue Director-General of Observatories (India) has 
issued a memorandum dated August 9 on the monsoon 
conditions prevailing during June and July, with 
anticipations for August and September. From the 
recent data regarding the conditions most likely to be 
of influence, and which are stated in detail, the un- 
favourable factors appear to predominate slightly. But 
the inferences drawn are (a) that the total rainfall of 
the months in question will probably be normal or in 
slight defect, (b) that in north-west India the mon- 
soon is not likely to be affected prejudicially by snow- 
fall. (The fall of temperature and dry north-westerly 
winds that usually follow widespread and heavy snow- 
fall have not been experienced.) The above forecast 
aerees practically with that issued on June 8 (NaturE, 
August 7). 
Dr. Nits Exkuortm has contributed an important 
article on the weather in the North Sea during the 
first half of June, 1911, illustrated by synoptic charts, 
to No. 64 of the Occasional Publications issued under 
the authority of the International Council for the 
Study of the Sea. The period is chosen because the 
council had then six hydrographical expeditions 
stationed in that sea. The author prefaces his inquiry 
by a careful historical summary of the development of 
meteorology and its methods from the invention of 
the barometer to the present time, and with a descrip- 
tion of barometric changes and their relation to wind 
and weather, in which we were pleased to see that the 
valuable pioneer work of Admiral FitzRoy, the first 
chief of the Meteorological Office, is duly recognised. 
Tne author explains that the difficulties with which 
modern conceptions of cyclones and anticyclones have 
to contend led him to supplement the usual isobaric 
charts by plotting the + differences of barometric 
readings since the last observation, and thus con- 
structing “‘isallobars,”’ or lines of equal differences. 
He remarks, inter alia, that a close study of the move- 
NO. 2290, VOL. 92| 
NATURE 
85 
ments of the isallobars shows that pressure changes 
are the primary, and cyclonic and anticyclonic whirls 
the secondary phenomena. The charts for the North 
Sea for the above period and two other cases are 
| discussed upon those principles. 
Dr. H. GEIGER, of the Reichsanstalt, who four 
years ago, in conjunction with Prof. Rutherford, 
devised a method of counting the number of a particles 
emitted by a radio-active body, has now, according to 
a communication from the Reichsanstalt, succeeded 
in perfecting a very simple method which allows both 
the « and 8 particles to be counted. The 
a or 6B rays are allowed to enter a short metal 
cylinder 2 cm. diameter, by a small hole in the base. 
Through an ebonite block which closes the other end 
of the cylinder a sharp pointed rod projects into the 
cylinder to within o-8 cm. of the base. The cylinder 
is raised to about 1200 volts, and the pointed rod is 
connected to a string electrometer provided with a 
high-resistance leak. The entry of either an « or a 
8 particle into the cylinder causes a spark to pass 
between point and cylinder, and the electrometer of 
10 cm, capacity acquires a charge corresponding to 
10-20 volts. The throws of the electrometer are 
recorded photographically, and the results obtained are 
in agreement with those calculated from ionisation 
observations in the case of the polonium preparation 
used in the observations. 
Engineering for September 5 contains an illustrated 
account of the Sulzer-Diesel locomotive built by 
Messrs. Sulzer Brothers at Winterthur, in the early 
part of this year, and supplied to the Prusso-Hessian 
State Railway, Berlin. This is the first locomotive 
fitted with Diesel engines, and is designed for fast 
traffic. The length over-all is 54-5 ft., and the weight 
in working order is 95 tons. The main engines are 
of the reversible two-cycle type, single-acting, having 
two pairs of cylinders inclined at go° to each other. 
The pistons are 15 in. diameter by 21-7 in. stroke. 
Running at 304 revolutions per minute, a speed of 
sixty-two miles per hour is obtained. The auxiliary 
machinery required is of a somewhat complicated 
character. Trials have been made, and show that the 
engine is adaptable to a wide range of work. It is 
reported that the change from air to oil-fuel is accom- 
plished without trouble at a speed of about six miles 
per hour, and that the reversing arrangements were 
equally successful. 
Engineering of the same date has an article dealing 
with problems of the internal-combustion locomotive, 
in which further reference is made to the Sulzer- 
Diesel locomotive. Our contemporary considers that 
any locomotive engineer reading the full description 
of this engine would be somewhat appalled at the 
extraordinary amount of machinery the type involves. 
The main engine requires another engine, of one- 
quarter or one-fifth of its power, to make it start at 
all. The second engine, also of Diesel type, requires 
similar provision in the way of air and circulating- 
water supply, &c., to the main engines, involving 
pumps for the supply of starting air, scavenging air, 
injection air, fuel to each cylinder, jacket water, circu- 
lating water for pistons, and for lubrication of bear- 
