Juty 4, 1912] 
NATURE 
453 
in the age of Aspelut, about B.c. 7oo. In this 
period Egyptian influences predominated in art, as 
witness the small objects found in the Lion Temple 
and the building of the Temple of Isis. The Sun 
Temple must also be assigned to this period, as 
well as the foundations of the Temple of Ammon 
on the outskirts of the city. In the second period, 
which archeology assigns to 300 B.C., the 
Egyptian motives gave way entirely to Greek, 
as witness a small cameo of galloping horses found 
last year, and the semi-classical statues and general 
design of the baths just described. This result 
would seem to accord entirely with what is told 
of Ergamenes by Diodorus. The third period 
begins, apparently, with the Christian era, and 
seems, so far as it has been developed, to have 
been dominated rather by Roman ideals, and it 
lasted, so far as determined, down to the middle 
of the 4th century, A.p., when there is a historical 
account of the invasion of a King of Axum. 
The following axial bearings to magnetic north 
supplement those given by Prof. Garstang in his 
“Meroé,” p. 26, n. 9 :— 
Royal Palace ... 294, 17° E. 
Do. sco, 2ORM eee 
Frescoed Hall... 292, 25° 30’ E. 
Prostyle Temple 97, 29° E. 
Royal Baths ... 195,),0.-1 
(East Wall) Beg 8 
Royal City  ...  290,) 
(Main N.W. Wall) 
The magnetic deviation on December 27, 1910, 
was determined by observation of Betelgeuse and 
e Pegasi as follows :— 
Axis of Temple of Ammon, 260. 
True Bearing : 
Magnetic Bearing : 
294° 3° 51°90") 
297 
The latitude and longitude of a point in this axis 
on the east wall of the Royal City are as 
follows :— 
Lat. 16° 57’) 
Long. 33° 42'J 
COMMITTEE ON SIGHT TESTS FOR 
SEAMEN.? 
pH Departmental Committee appointed by the 
Board of Trade, in June, 1910, has reported 
at considerable length on the questions submitted 
to it, and has, it may be hoped, brought the 
controversy concerning them to a conclusion. 
The Committee was appointed 
“to inquire what degree of colour-blindness or de- 
fective form vision in persons holding responsible 
positions at sea causes them to be incompetent to 
discharge their duties, and to advise whether any 
and, if so, what alterations are desirable in the Board 
of Trade sight tests at present in force for persons 
serving or intending to serve in the Merchant Service 
or in fishing vessels, or in the way in which these 
tests are applied.” 
The Royal Society was represented on the Com- 
mittee by Lord Rayleigh and by Profs. Gotch, 
Poynting, Rucker, and Starling, or, after the 
beginning of 1911, by Prof. Sherrington in the 
place of Prof. Starling; and the Committee 
I Report of the Departmental Committee on Sight Tests. (London: 
Wyman.) Price 44d. 
NO. 2227, vol. 89] 
examined a large number of men of science, of 
ophthalmic surgeons, and of practical seamen, and 
conducted a large number of experiments, some of 
them at Shoeburyness, where distant lights could 
be observed, and the essential conditions of actual 
service be reproduced. 
The Committee obtained the assistance of colour- 
blind persons in these experiments, and profited 
by their mistakes; and it heard the evidence, and 
examined the apparatus, of Dr. Edridge Green 
and other gentlemen. Finally, in the wool test 
for colour vision, it recommends the substitution 
of a dark brown skein for the red one hitherto 
employed, and, in the conduct of the test, the 
division of the whole collection of skeins into as 
many groups as there are test skeins. Each group 
should be composed of a fixed number of skeins 
which resemble the test skein, and a fixed number 
of those which colour-blind persons are liable to 
cenfuse with it; and candidates should be required 
to divide each group into two parts, those which 
resemble the test skein, and those which do not. 
As an addition to the test thus modified, the 
Committee recommends the use of a lantern de- 
signed for the purpose, and capable of showing 
either a single light, through a circular opening 
of o'2 inch in diameter, or two lights, through 
holes each o’o2 inch in diameter, and separated by 
a distance of one inch. This lantern is placed at 
the level of the candidate’s eyes, and the candidate 
and examiners stand alongside of it, and observe 
the lights as reflected in a plane mirror ten feet 
from the lamp. At this distance the angular mag- 
nitude of the large aperture is equal to that of 
a ship’s light at 200 yards, and the angular mag- 
nitude of the two smaller apertures corresponds 
to that of a ship’s lights at 2000 yards. These 
are sufficient to test imperfect vision, but are well 
within the limits of visibility of normal persons. 
The Committee recommends that both this 
lantern and the modified wool test should be used 
in examining the colour vision of all candidates, 
and believes that it would be unnecessary to re- 
examine for colour vision any person who had 
passed them. It also recommends that the more 
rigid test for form vision ordered by the Board 
of Trade to come into operation in 1914 should be 
adhered to, that any officer holding a certificate 
whose visual acuteness in the better eye has fallen 
below half normal should be considered incom- 
petent, and that steps be taken to impress upon 
parents and guardians, and upon shipowners 
taking apprentices, the desirability of submitting 
boys to an expert examination before they adopt 
the sea as a profession. ; 
A highly important further recommendation is 
that, whenever judicial inquiries into the causes of 
shipping casualties are being held, witnesses who 
give evidence as to the nature and position of 
coloured signals or lights should always be tested 
for colour and form vision. The report is signed 
bv all the Commissioners, but Sir Norman Hill 
appends a memorandum dissenting from certain 
portions of the recommendations with regard to 
form vision. 
