258 REPORTS ON THE STATE OF SCIENCE.—1914. 
the mistaking of the colour ofa light. The Manager of the Hull Steam 
Trawlers’ Mutual Insurance and Protection Co., Ltd., who in 12 years 
has had to deal with an average of 100 collisions a year, knows of 
only four cases in which any question of defective vision has arisen. 
Two of these cases were in elderly men, and in the other two the 
witness considered the danger was caused by excessive smoking.’ 
Clause 17.—' The Board of Trade casualty returns, which include 
collisions to foreign ships on or near the coast of the United Kingdom 
and of British Possessions, show no case in which a sea casualty has 
been attributed to the defective vision either of an officer or a look-out 
man; but they show that since the adoption of the 1894 sight tests 
there have been reported on the average each year 100 collisions 
attributed to bad look-out and 429 strandings attributed to causes con- 
nected with navigation and seamanship. The strandings resulting 
from bad look-out are not shown separately. From these returns it is 
not possible to arrive at any reliable estimate of the total number that 
might have been occasioned by the defective vision of the officer in 
charge or of the man on the look-out. Further, the returns, as they 
do not distinguish the vessels commanded by officers who have passed 
the 1894 sight test, afford only a general basis of determining how far 
the existing system has been successful in eliminating dangerously 
defective men; but they do show that amongst the vessels registered in 
the United Kingdom the total number of collisions attributable to bad 
look-out and of strandings attributable to all causes relating to naviga- 
tion and seamanship is less than 500 a year. The Board of Trade has 
no record of the actual number of voyages made by British vessels, but 
on a rough estimate that number cannot be less than 300,000 a year.’ 
Clause 18.-—‘ There appears to be no evidence showing conclusively 
that defective vision has caused any appreciable number of accidents at 
sea, although we do not think that it necessarily follows from this that 
the present method, even where it has been employed, has been success- 
ful in excluding all dangerous persons from the Mercantile Marine, or 
that no accidents have been caused in this way, since it has not been 
the practice, in conducting inquiries into the causes of casualties, to 
test the vision of persons implicated: We think it regrettable that 
effect has not been given to the recommendation as to the testing of 
witnesses contained in the report of the committee of the Royal Society 
in 1894, and we desire to repeat that recommendation—that in case 
of judicial inquiries as to collisions or accidents witnesses giving 
evidence as to the nature or position of coloured Signals and lights 
should be themselves tested for colour and form vision. 
Sir Norman Hill, who signed the Minority Report, states that ‘ 
the absence of all evidence of any single casualty resulting from defec- 
tive form vision I am opposed to the retention of the new standard 
under which 10 per cént. of the candidates who have for many years 
proved their competency would have been excluded from the service.’ 
Mr. Nettleship, however, one of the members, since the publication of 
the Report, made a collection of the cases in which disaster at sea or 
land seemed to be actually or potentially due to these causes, and was 
in communication with the writer in regard to the details of a number 
