Marcu 31, 1904] 
NATURE 
525 
candidates for appointment to commissions will be required 
to obtain either a ‘‘ leaving ’’ certificate or a ‘‘ qualifying ”’ 
certificate. A “leaving ’’ certificate is one including the 
same subjects as a qualifying certificate, and granted by a 
recognised body to candidates not less than seventeen years 
of age who have attended three years’ continuous teaching, 
with satisfactory conduct, in a properly inspected school. 
A “qualifying ’’ certificate is one covering two classes of 
subjects. All candidates must qualify in the subjects of 
class i., viz. English, English history and geography, and 
elementary mathematics. Candidates must qualify in two 
of the subjects of class ii., viz. science, French or German, 
Latin or Greek. The expression ‘‘ science,’’ the rules state, 
means so far as a leaving certificate is concerned, ‘‘ such 
combination of experimental or natural science as the Army 
Council may approve, provided always that the sciences 
recognised shall have been taught in a sufficiently extended 
course, including a due amount of laboratory or field work.”’ 
Any leaving certificate accepted must certify that the candi- 
date has taken a sufficient course of elementary geometrical 
drawing and practical geometry, and also an elementary 
course of practical measurements. Leaving certificates will 
be accepted from the Oxford and Cambridge University 
examining bodies, the University of London, the Scottish 
Education Department, and such universities in Great 
Britain as undertake to issue_a certificate satisfying the re- 
quired conditions. The same bodies will hold examinations 
periodically at which candidates who desire to obtain 
qualifying certificates may present themselves. 
SOCIETIES AND ACADEMIES. 
Lonpon. 
Royal Society, March 3.—‘‘The Spectra of Antarian 
Stars in Relation to the Fluted Spectrum of Titanium.”’ 
By A. Fowler, A.R.C.S., F.R.A.S. 
The distinguishing feature of the spectra of the Antarian 
stars (Secchi’s third type) is the system of apparently dark 
flutings, sharp towards the violet and fading off towards 
the red end of the spectrum. The principal flutings are 
well seen in Antares, but they are more strongly developed 
in the spectra of a Herculis and o Ceti, in which stars 
additional details are also seen. These flutings have not 
hitherto received a definite chemical interpretation, and it 
has been uncertain, owing to the possibly misleading effects 
of contrast, whether the spectrum was to be regarded as 
one consisting wholly of absorption flutings fading towards 
the red, or as one partly consisting of emission flutings 
fading in the opposite direction. 
The purpose of the present communication is to state the 
nature of the evidence which indicates that the spectrum is 
essentially an absorption spectrum, and that the chief sub- 
stance concerned in the production of the flutings is 
titanium, or possibly a compound of that element with 
oxygen. 
The flutings in question come out in the are spectrum of 
titanium oxide, if the precaution be taken to provide a 
liberal supply of material and to use a very long arc, taking 
care also that the image of the ‘‘ flame ’”’ is projected on 
the slit of the spectroscope. They are also seen in the arc 
spectrum of the chloride under similar conditions. 
Numerous lines accompany the flutings produced in this 
manner, and some of the details are consequently masked 
or not recognised without careful study of the photographs. 
So far the flutings have not been very successfully produced 
in the oxyhydrogen flame; they are visible in the flame 
spectrum of the fumes from the chloride, but their observ- 
ation is difficult on account of the bright continuous spec- 
trum, The best representation of the flutings has been 
obtained by passing a spark, without jar, through the fumes 
of oxychloride which rise from the chloride of titanium on 
exposure to air. In these circumstances the lines which 
appear are not numerous, and some of the secondary flutings 
which are masked by lines in the spectrum of the flame of 
the arc are readily detected, in spite of the continuous 
spectrum which is also present. 
The wave-lengths of the heads of the principal flutings 
are 6162-5, 5604-5, 5447-0, 5241-0, 5167-5, 4955:I1, 4761-6 
and 45843, and it is found that these agree within the 
NO. 1796, VOL. 69 
possible limits of error with eight of the ten principal bands 
tecorded in the stars by Vogel and Dunér. 
The origin of the two outstanding bands at 5862 and 
6493 has not yet been ascertained, but in the case of the 
remaining flutings the evidence for titanium is enormously 
strengthened by a discussion of their structure and by ex- 
tending the comparison further into the violet. Photo- 
graphs of the stellar spectra, especially those of o Ceti and 
a Herculis, show that some of the principal flutings are 
composite, Dunér’s band 10, for example, containing, 
according to Sidgreaves, four distinct flutings separated by 
intervals of about 44 tenth-metres, each of which is weaker 
than the one which precedes it on the more refrangible 
side. A precisely similar structure is found in the case of 
the titanium flutings, and a comparison of wave-lengths 
indicates that the various components occupy the same 
positions as those in the stars, so far as the available 
measurements permit the test to be applied. 
The table of wave-lengths given in the paper shows that 
the details of the titanium flutings are reproduced with 
remarkable fidelity in the stellar spectra, and more especially 
in o Ceti. There is some uncertainty in connection with the 
complicated groups of flutings and lines extending from 
5598 to D, which need further investigation in the stellar 
spectra with instruments of greater dispersion, but the 
general agreement is such as to leave no reasonable doubt 
that titanium is the main factor in the production of the 
dark flutings which characterise the Antarian group of. 
stars. 
This explanation of the dark flutings suggests that the 
appearance of bright flutings in the Antarian spectrum 
arises chiefly from effects of contrast. It does not, of 
course, exclude the possibility of the presence of bright 
flutings, such as might be indicated by local brightenings 
which are not exactly in coincidence with the edges. of 
dark flutings. 
“An Inquiry into the Nature of the Relationship between 
Sun-spot Frequency and_ Terrestrial Magnetism.’”’ By 
C. Chree, Sc.D., LL.D., F.R.S. 
(1) The formula 
(1), 
where R is some magnetic quantity such as the amplitude of 
the diurnal oscillation of the needle, a and b constants, and 
S sun-spot frequency (after Wolf and Wolfer), was first 
applied by Wolf to the mean declination range throughout 
the year. 
The present paper is entirely devoted to the connection 
between sun-spot frequency and terrestrial magnetism. It 
deals with data from Milan (1836-1901), Greenwich (1841- 
96), Pawlowsk and Katharinenburg (1890-1900), Batavia 
(1887-98), and Mauritius (1875-90). It aims at ascertain- 
ing wherein the results in my previous paper (Phil. Trans., 
A, vol. ccii. p. 335) are peculiar to the station or period 
dealt with. 
It investigates what differences may exist between the 
sun-spot connection on ordinary days and on magnetically 
quiet days, and what differences arise when one applies (1) 
to the mean of the differences between the absolutely highest 
and lowest daily readings, instead of to the range of the 
mean diurnal inequality. It also considers various measures 
of the magnetically disturbed character of the year, and 
their relation to sun-spot frequency. 
There seems a general tendency for b/a to increase as 
we pass from a quantity, such as the range of a diurnal 
inequality, which is comparatively independent of disturb- 
ances, to a quantity such as the mean absolute daily range 
which is largely dependent on disturbances. Formula (r) 
becomes, however, less and less strictly applicable, the more 
disturbed the magnetic quantity to which it is applied. 
When we consider quantities such as the mean of the twelve 
monthly ranges (maximum and minimum for the month), or 
the annual range (maximum and minimum for the year), we 
find large differences between observed values and those 
calculated from (1). 
In the case of ranges from mean diurnal inequalities for 
the year, the agreement between observed and calculated 
values is about equally good at Pawlowsk, Katharinenburg, 
Batavia, and Kew. In the case of declination, the mean 
difference between observed and calculated values is about 
