442 
NATURE 
[Marcr 31, 1923 
Research Items. 
ARCHHOLOGICAL EXPLORATION AT ZIMBABWE.—A | 
noteworthy contribution to the discussion of the 
origin and date of the Zimbabwe ruins appears in the 
recently issued vol. xx. of the Proceedings of the 
Rhodesian Scientific Association in the form of a 
communication from Mr. H. R. Douslin, lately 
Director of Public Works, on “‘ Recent Explorations 
at Zimbabwe.” Mr. Douslin has excavated the ruins 
on two occasions. In 1909 the trench made by Dr. 
Randall-MaclIver in 1905 was carried down to solid 
rock by a pit under the wall of the Temple. The 
base of the foundations was reached at about 2 ft. 
and the rock at about 1o ft. below surface level. 
Only broken pottery, of a type common to all the 
ruins and similar to that made by natives to-day, 
was found. In 1915 excavations were carried out 
inside the wall of the Acropolis, which it is assumed 
was built before the Temple, and a large part of the 
red-earth filling was removed. The original entrance 
was discovered—a passage many feet below what is 
considered to be the original foundation of the wall 
on the western side. It ended against a dead wall 
of the internal red-earth filling. This filling, on 
which many of the internal walls are built, would 
therefore appear to be of more recent origin than the 
main outer wall. Solid rock was reached at about 
ten feet below present surface level, where the old 
dwellings were found. Their workmanship is 
superior to that of present-day natives and of a 
character unknown to them. The finds included 
two finely ornamented copper bands, an iron shackle, 
assegais, fragments of a soapstone bowl, and the 
usual Kaffr beads and pottery. No gold was found, 
and the author points out that the gold ornaments, 
etc., for which the greatest antiquity has been 
claimed, were found on or near the surface ten feet 
above the original occupation level. 


SOCIAL SIGNIFICANCE OF U.S. ARMY INTELLIGENCE 
Tests.—Prof. P. E. Davidson discusses in the 
Scientific Monthly (February 1923) some of the 
generalisations which have been drawn from the 
now well-known American Army intelligence tests. 
These tests, originally applied in order to differentiate 
men for army posts, disclosed the unwelcome fact 
that large numbers of the population ranked very 
low in innate intelligence. Some writers have 
concluded from this that the traditional democratic 
ideal must be renounced, as only a gifted few are 
capable of ruling. The writer of the article believes, 
however, that three assumptions have to be made 
if such conclusions are sound: (i.) that the army 
draft was truly representative of the American 
population in general; (ii.) that the tests were 
really tests of native ability and not of educational 
advantages; (iii.) that the native intellect in 
question is so general as to condition social success 
of any significant kind. He gives reasons for dis- 
puting each of these assumptions, and shows that 
large numbers of the more intelligent members of 
the community were unrepresented, that the tests 
made heavy demands on language knowledge, and 
that many factors other than native ability help 
to determine a man’s social position. While agree- 
ing that the gifted minority should have every 
possible advantage, he disputes the belief that these 
alone should be trained, while large numbers are to 
be denied training because of an arbitrarily imputed 

stupidity. The article gives a salutary and timely 
check to the ardent enthusiasts who would impute 
to tests more than they can legitimately bear. It 
is frequently the social applications of scientific 
research that are unscientific. 
NO. 2787, VOL. 111] 
EFFICIENCY IN FINE LINEN WEAVING.—A report 
on fine linen weaving has been prepared by Mr. 
H. C. Weston on behalf of the Industrial Fatigue 
Research Board (Report No. 20, ‘““A Study of 
Efficiency in Fine Linen Weaving,’ Textile Series 
No. 5, H.M.S.O., 1922, 1s. 6d. net). The investiga- 
tion was undertaken for the purpose of enabling a 
comparison to be made between the conditions of 
work and efficiency in linen-weaving sheds and in 
cotton-weaving sheds, the latter having previously 
been investigated. The output from each of forty 
looms was recorded, hourly readings of the wet- 
and dry-bulb temperatures were taken, and the 
amount of time noted during which artificial light 
was used. A detailed description of the nature of — 
the weaving process is given and the general condi- 
tions of the sheds. Tables showing the hourly, 
diurnal, daily and weekly variations of efficiency 
and temperature are appended. The writer con- 
cludes that there is evidence to show that the eco- 
nomic limit of temperature for fine linen weaving is 
reached when the wet-bulb temperature exceeds 
73° F. Up to this limit increase of temperature 
results in increase of productive efficiency, but 
beyond it efficiency falls owing to the discomfort 
and fatigue of the workers. He also shows that the 
use of artificial light reduces efficiency approximately 
by 11 per cent. of its normal daylight value. A 
similar result was reported in a previous investigation 
made by the Industrial Fatigue Research Board 
into silk-weaving. These results are not unworthy 
of consideration in discussions of daylight saving. 
THE DISTRIBUTION OF MEGALITHIC MONUMENTS 
IN ENGLAND AND WateEs.—In the Proceedings of 
the Manchester Literary and Philosophical Society 
(vol. Ixv. No. 13) Mr. W. J. Perry supplies some 
further arguments in support of his theory that 
megalithic monuments were the work of a race of 
miners engaged in the search for precious metals and 
other valuables. This he holds to be established in 
the cases of Cornwall, Devonshire, Wales, Derby- 
shire, Northumberland, and Cumberland. The diffi- 
culty remains regarding those in Dorset, Wilts, and 
Oxford, including Stonehenge and Avebury. The 
explanation is that this latter series is situated on 
the Upper Chalk flint-bearing formation. “ Flint 
implements,” he remarks, “are found in all parts 
of the country, even in places far away from the 
source of the material. Sir John Evans mentions 
particularly Devon and Cornwall as regions where 
there is an abundance of flint implements and flakes, 
and these counties have no flint-bearing formations, 
though in some places there are some on the surfaces. 
These would not be nearly so good for the purpose 
as those from the chalk regions of Wilts and Dorset. 
We have thus the remarkable fact that flint imple- 
ments are found all over the country, and that the 
builders of megaliths, including long barrows, have 
chosen out those very portions of the chalk country 
which produce flints.”” 
DISTRIBUTION OF ORGANISMS IN CULTURE MEDIA.— 
As a rule the accuracy of biometrical determinations 
must be ascertained empirically from a statistical 
study of the observations; in certain cases, as has 
been shown in the theory of hemocytometer counts, 
the law of variation may be calculated, and the 
accuracy known with precision, provided the tech- 
nique of the counting process is effectively perfect. 
A study of the extensive bacterial count data 
accumulated at Rothamsted by Cutler and Thornton, 
using Thornton’s agar medium, indicated that the 
