JuLy 17, 1902] 
NATURE 
287 
representing deities and saints. The whole of the relievo work 
had originally been coloured, and there were fresco paintings 
besides. The excavations of these relievos proved no easy task, 
as the structures threatened to collapse when the sand was 
removed. Yet Dr. Stein succeeded in clearing ninety-one large 
and numerous small relievos. Photos were taken of the larger 
relievos, while the smaller ones were taken to England. In 
style and details of execution the Rawak sculptures resemble the 
Greeco-Buddhist sculptures of the Peshawar Valley and the 
neighbouring regions. Chinese copper coins, found among the 
rains, proved to be coins of the Han dynasty. As the rule of 
the kings of this dynasty covers the period of 25-220 A.D., and 
some of their coins are known to have been current until the close 
of the fourth century, we have thus a chronological limit, to 
which the Rawak sculptures may safely be referred. 
Finally, we must at least touch upon one negative, though 
none the less important, result of Dr. Stein’s journey of explora- 
tion. During his last eight days’ stay at Khotan he succeeded 
in clearing up the doubts he had long entertained concerning the 
genuineness of certain very puzzling manuscripts and blockprints 
‘in unknown characters” which had for some years past been 
purchased from Khotan and added to the ‘‘ British Collection of 
Central-Asian Antiquities ” in Calcutta. With the help of the 
Chinese authorities he got hold of the very man—one Islam 
Akhin—from whom most of these documents had been bought. 
The man was brought before Dr. Stein, who forced from him, in 
the course.of a prolonged cross-examination, an open confession 
of his manufacture of ‘‘old books.” Dr. Stein has shown that 
it is easy to distinguish the forgeries from genuine old manu- 
scripts, and there is no fear that any scholar will, in future, be 
deceived into trying to decipher the “‘ unknown characters” of 
Khotan manuscripts. 
This brief sketch will suffice to give an idea of the singular 
importance of the discoveries made by Dr. Stein. But the 
costly treasures brought by him from Chinese Turkestan will 
require the most careful examination and study to be made 
fruitful for further research, and who could be better fitted for 
this task than the happy discoverer himself? While con- 
gratulating both the Indian Government and Dr. Stein on the 
brilliant discoveries made in Central Asia, we can only express 
our sincerest hope that the authorities of the India Office may 
see their way to grant Dr. Stein the leisure required for com- 
pleting the work so happily begun, in order that the present 
‘* Preliminary Report’? may soon be followed by a Detailed 
Report of Dr. Stein’s tried workmanship. 
M. WINTERNITZ. 
UNIVERSITY AND EDUCATIONAL 
INTELLIGENCE. 
THE authorities of Reading College have received an intima- 
tion that the Treasury recommends the advancement of the 
College to the list of University Colleges, with a Government 
grant of 1000/. a year for five years. The grant will be subject 
to the Treasury audit, but local subscribers have assured the 
necessary income. 
Pror. HEWLETT, director of the Department of General 
Pathology and Bacteriology at King’s College, London, has 
arranged a vacation course in practical and clinical bacteriology 
to commence Wednesday, August 6, and end Saturday, August 
16. The course will consist of lectures, demonstrations and 
practical work; in the latter, the members of the class will 
make for themselves permanent preparations of the chief 
pathogenic micro-organisms and will carry out the principal 
manipulations employed in bacteriological investigations. 
A MEETING of numerous representatives of primary, second- 
ary (including technical) and other branches of education was 
recently held at the Municipal School of Technology, Man- 
chester, to consider whether arrangements should be made for 
a conference of science teachers in the north of England on 
the lines of those established by the Technical Education 
Board of the London County Council, which have been held in 
London during the Christmas vacation for some years past. 
The proposal to hold similar conferences in the north of 
England was unanimously adopted, and a committee formed to 
make the necessary arrangements. The first conference will 
be held on Friday and Saturday, January 2 and 3, 1903, at 
Manchester. 
NO. 1707, VOL. 66] 
A tist of requirements and courses at the Clarkson Memorial 
School of Technology, Potsdam, New York State, has been 
received. The institution was founded in 1895 to provide 
technological education of college standard, and is a constituent 
college of the University of the State of New York. It is of 
interest to note that the regular courses of work extend over 
four years and that satisfactory evidence of thorough preparation 
must be given by students who wish to enter the college. 
Now that the London polytechnics are part of the University 
of London, efforts should be made to introduce or extend the 
same kind of regulations as to systematic work and preliminary 
studies. 
HiTHERYO none of the technical institutes has been specially 
organised for the optical trades, though optical classes have been 
held in several of them, notably in the Northampton Institute in 
Clerkenwell. But the optical trades appear to have awakened to 
the need of specialised instruction of the highest kind for the 
young men in their industry, and a movement to create a real 
Optical Institute is on foot. ‘The Optical Society has approached 
the Technical Education Board of the London County Council 
to urge upon it the creation of such an establishment. If the 
Techn ical Education Board could see its way to organise and 
equip a special technical school in optics, and endow it with 
a grant of 3000/. or 4ooo/. a year, we might expect great things 
for the future of the optical trades. When it is remembered 
how greatly the electrical industries of Great Britain have bene- 
fited by the electrical teaching and the electrical laboratories 
established twenty years ago by the City and Guilds Institute, 
one wonders why similar optical laboratories, properly equipped 
for the teaching of technical optics, have not been long ago 
organised. The present movement is a sign that England is 
waking up. 
SOCIETIES AND ACADEMIES. 
LONDON. 
Royal Society, February 13.—‘‘ The Refractive Indices of 
Fluorite, Quartz and Calcite.” By J. William Gifford. Com- 
municated by Prof. Silvanus P. Thompson, F.R.S. 
Tables are given of the refractive indices of the above sub- 
stances for twenty-six wave-lengths, from wave-length 7950 
Rb to wave-length 1852 Al inclusive at 15° C., and of the tem- 
perature refraction coefficients. To ensure accuracy a new 
method of observation was adopted. The prisms were polished 
on three sides, and deviations were measured at each of the 
three angles. The indices were calculated by the formula 
= sin 4(D + 60°)/sin 30°. 
The difference of the angles of the prisms from 60° were in 
each case less than 4 seconds of arc. When this is the case 
the error introduced is less than 0’0000001 in the index. It is 
not, therefore, necessary to measure the angles with accuracy. 
Some of the rays from the collimator are reflected from the 
base of the prism and enter the telescope. The image of the 
slit thus obtained coincides with the refracted image only when 
minimum deviation is reached. In cutting the goniometer 
circle a burr is thrown up by the engraving tool on each side of 
every division. By two small electric lamps behind the reading 
microscope either or both burrs are made to appear as fine white 
lines. With the help of quartz fibres measurements are made on 
these and the mean taken. A correction is made for the error 
of the reading microscope, and special precautions have been 
taken to ensure the optical correctness of the prisms. An exact 
copy of the original measurements for line C fluorite is given. 
An approximate estimate of the total error gave for the 119 
indices in the table, 
33 less than... 0°0000023 
39 » 0°0000034 
31 “A =i 00000084 
I5 more than ... 070000084 
I only as great as but } .. 
not more than... { ° eS 
Some indices for left-handed quartz are given, and a rough 
determination of the specific gravities of right and left quartz. 
The partial and proportional dispersions of fluorite, quartz and 
calcite for the visual spectrum and their lens combinations are 
also given, together with a list of focal lengths for unity and a 
table of curves for the whole spectrum with ordinates for a 
mean focal length of six thousand nine hundred and eighty- 
five millimetres, 
