16 NAL OTR 
Marcu 7, 1912 
7 
foot, would be greatly preferable, and equally that a 
gun with a larger muzzle than that employed would 
have been better. 
Tue annual general meeting of the Institute of 
Chemistry was held on March 1, Dr. George Beilby, 
F.R.S., the president, occupying the chair. During 
the course of his address the president said the fund 
for new buildings for the institute has reached S5ool., 
but 15,0001. is considered necessary for erecting a 
building suitable for the worl of the institute. 
Touching on the difficulties which confront public 
analysts and private practitioners, he referred to the 
attempts made on the part of certain local authorities 
to lower the status of the professional chemist by 
offering appointments at ridiculous remuneration. 
Enlightened municipal bodies realise that the proper 
administration of statutes, such as the Sale of Food 
and Drugs Act, cannot be expected unless they attract 
to their appointments men of competence and 
integrity, who can hold their own as responsible re- 
presentative officers of their authorities. The Act is 
as much a statute against fraud as in the interests of 
public health, and it must be understood that the 
public analyst is in no way subject to the control of 
the medical officer of health. Prof. R. Meldola, 
F.R.S., was elected as president for the ensuing year, 
and the following as vice-presidents:—Dr. G. T. 
Beilby, F.R.S., Dr. F. Clowes, Dr. G. McGowan, 
Sir Alexander Pedler, F.R.S., Dr.’ J. M. Thomson, 
F.R.S., and Sir William Tilden, F.R.S. 
Tue Bulletin of the Bureau of Standards for 
December 15, 1911, contains an account of an investi- 
gation carried out by Mr. F. W. Grover on the effect 
of temperature and frequency on the capacity and 
phase difference of a number of commercial paraffined 
paper condensers. The alternating currents used 
were supplied by special generators designed for the 
Bureau. Bridge methods were used, balance being 
indicated by a vibration galvanometer. The phase 
differences found range from 6’ to 22° of are. 
The change of capacity with frequency is large 
for low frequencies, and decreases as the frequency 
increases. The temperature coefficient of capacity is 
generally positive and of the order 1 per cent., but 
in some cases may be negative. The absorption 
appears to be represented with a fair degree of 
accuracy by Von Schweidler’s extension of Pellat’s 
theory that the dielectric displacement on the appli- 
cation of an electric field attains instantly a certain 
fraction of its final value, and then increases ex- 
ponentially to its final value. Three exponential 
terms appear to be necessary to represent the observa- 
tions. It follows from these results that paper con- 
densers cannot serve as standards of capacity, and 
should not be used in any work in which a constant 
capacity is required. 
COMMENTING on the fatal accident to Mr. Graham 
Gilmour, Engineering for March 1 considers that if 
the trussing of his machine was after the usual 
pattern in this type of machine, the provision for 
horizontal strength would not be very great, and 
NO. 2210, VOL. 89| 
failure would most likely be in this direction. The 
essential lesson in this and previous accidents appears 
to be that it is high time that the question of the 
strength of monoplane wings was gone into in a 
public manner, and that it is due to the public that 
the makers should demonstrate that they have a 
reasonable factor of safety, both vertically and hori- 
zontally, otherwise the monoplane in its present state 
will be put down as a machine in which safety has 
been so far sacrificed to the craze for ‘‘ records ”’ that 
it is not fit for practical flight. 
Turre have been several proposals within the past 
few years to construct internal-combustion air-com- 
pressors on the free-piston system, and one which has 
been made and tested by Signor Giuseppe Matricardi, 
of Pallanza, Lago Maggiore, Italy, is described in 
Engineering for March 1. A heavy piston is propelled 
from one end of a cylinder to the other end by the 
explosion of a gaseous mixture behind it. During 
its motion it expels air in front of it through a port, 
and thence through a non-return valve into a 
reservoir. Near the end of its travel the piston over- 
runs the port, and compresses into the end of the 
cylinder a fresh charge, which is exploded in its 
turn, shooting back the piston to the other end. In 
its passage the piston compresses and discharges into 
a reservoir the air in front of it, as before. It is said 
that a good efficiency and large output have been 
secured in the small machine already tested, but 
actual figures are reserved until a larger compressor, 
now under construction, is ready and tested by in- 
dependent engineers. 
We are indebted to Messrs. Cassell for a copy of 
the first part of a new issue of Kearton’s ‘ British 
Birds’ Nests.’’ The fact that bitterns nested last 
year in Norfolk is recorded. 
Tue first part of ‘‘ The Nature Book,’’ which is 
described in a subtitle as a popular description by 
pen and camera of the delights and beauties of the 
open air, has been published by Messrs. Cassell and 
Co., Ltd. The work is to be completed in thirty-six 
fortnightly parts, at 7d. net each. It is profusely 
illustrated from photographs and a series of coloured 
plates. 
THE report of the ninth meeting of the Inter- 
national Meteorological Committee, held at Berlin in 
September, 1910, and of the sixth meeting of the 
Commission for Terrestrial Magnetism and Atmo- 
spheric Electricity, which preceded it, has just been 
published as a lue-book (Meteorological Office, 
No. 208, price 3s.). 
Tue “ Classified List of Smithsonian Publications 
available for Distribution, January, 1912,’’ has been 
received from Washington. Applicants for these 
publications are requested to state the grounds of 
their requests, as the Smithsonian Institution is able 
to supply papers only as an aid to the researches in 
which applicants are especially interested. The 
papers included in the list are distributed gratis, 
except in some eases, where a small charge is made. 
eet ee 
