they do not actually know of the defect to which they are subject--may
possess in every other way the keenest eyesight; and it by no means
follows that a man who is colour-blind has in any other way less
perfect eyesight than an artist or any other person whose calling
requires nicety of distinction in the matter of colours and hues.
The question occurs, To what is colour-blindness due? In certain
cases, to a want of education of the eye in this particular service;
but more generally to local causes and diseases, and to hereditary
defect. Instances occurring under the first-named class are not real
cases of colour-blindness. It is really no more true to say that a
man is colour-blind because he calls red 'green,' or blue 'yellow'
persistently, and with a perfect appreciation of the difference, simply
because he has never been taught, than it is to call a man blind who
calls an oval 'round,' because he has learned no better. But in the
other instances the colour-blindness is a true defect. In Egypt, China,
and other countries where ophthalmia is prevalent, colour-blindness
is common; and the peculiar light which exists in certain localities
where there is a large expanse of flat sandy soil, and which is known
to be very trying to the eyesight, is very often found to produce this
defect where it does not otherwise impair the vision. Hereditary cases
of colour-blindness are common. The painter Turner has been said by
some of his critics to have been colour-blind; and we believe that one
of his sisters had a defect of vision which caused her to confuse one
colour with another in such a way as to prevent her from describing
accurately a picture placed before her.
In reference to the theory that the recent disastrous railway accident
at Arlesey was owing to a mistake of the engine-driver as to the colour
of the signal displayed against him, a correspondent of the _Times_
points out that colour-blindness may be acquired. 'A few years ago,' he
says, 'I was investigating colour appreciation, and the first instance
of the acquired defect that came to my knowledge was in the person
of an engine-driver. This man confessed, after an accident through
his not distinguishing the red signal, that he had gradually lost his
colour-power, which had been perfect; and so sensible was he of his
loss and its disadvantages, that before the accident he had determined
to give up the situation. The manager of the Company, who told me the
circumstance, assured me that this driver had been carefully examined
but a few years back and passed as possessing perfect sight.'
If a person with perfect sight will look steadily for a few moments
at any object, of one of the three primary colours, whether a lamp or
anything else, and then close his eyes, and watch so to speak, with his
closed eyes, he will find the object reproduced in a kind of cloudy
representation, or rather retained on the eye; but its colour will
be changed from the _primary_ to its corresponding (complementary)
_secondary_ colour. Thus the impression of a red object will present
itself as green; yellow as purple; and blue as orange. _Vice versâ_, if
the object is one of those secondary[A] colours, the reproduction on
the retina will be of the corresponding primary colour. In this way,
it is quite possible for a man, who has been looking for any length
of time at a red light on a railway at night, to remove his eyes for
a moment or two; and, on looking again at the lamp, to find that--in
the course of the natural relief afforded by the impression on the eye
resolving itself into the secondary colour--his sight is for a moment
impeded by the floating image (now green instead of red) before his
eyes, and the actual lamp (still red) covered, as it were, by the
retained figure, so that it appears to be green. This curious effect
is no fault of vision, and might easily mislead an engine-driver who,
having first actually seen the red light, has, after withdrawing his
eyes, immediately afterwards imagined it changed to green or white,
in indication of the removal of the obstacle to the progress of his
train. In this way, by continual straining of the eye in search of
a particular signal, especially at night, with no light beyond that
of the glaring furnace of the engine--in itself detrimental to the
eyes--it is quite possible that colour-blindness may be acquired, and
that a man who was once perfectly able to distinguish the most delicate
tints may become insensible to the effects of widely different colours.
Whatever its cause, it is a fact that colour-blindness does exist to a
very considerable extent. In Egypt this is so well recognised a fact,
that engine-drivers and others employed on railways are obliged to
undergo a special examination before they are allowed to proceed to
their duties. Many curious stories are told concerning the attempts
made by men suffering under this infirmity to escape the penalty of
detection; they will often rather run the risk of bringing themselves
and others to sudden death in a collision, than lose the coveted post
by admitting their defective sight. Sometimes a man will successfully
guess at the red, white, and green lamps or flags held before him;
but, if the examiner is as astute as the examinee, he will balk his
calculations by holding out a cap, or some other article not usually
classed among the list of railway signals, and an unguarded 'Red' or
'Green' from the lips of the candidate will send him ruefully off about
his business.
Researches lately made in Sweden shew that this peculiar defect of
sight is prevalent in that country. Out of two hundred and sixty-six
men examined recently by Professor Holmgren, eighteen were found to
be colour-blind; and in our own land statistics prove that Englishmen
are not free from the infirmity. The late Professor George Wilson, who
made a special investigation into the subject in Edinburgh some years
ago, stated that out of one thousand one hundred and fifty-four persons
of various professions examined in 1852, no less than sixty-five were
colour-blind; and of these, twenty-one specially confounded red with
green. A gentleman employing a number of men, writing to the _Times_,
states that recently he directed an upholsterer to cover some article
of furniture in green leather, and that the man used a skin of bright
red leather, not knowing the difference. He could only distinguish
colours in their intensity, all appearing to him as different shades of
gray.
But instances could easily be multiplied. The practical part of
the question is its bearing on the employment of men upon whose
sight and power of distinguishing colours many lives are dependent.
Engine-drivers and signal-men, railway guards and sailors, often have
nothing but a red or green speck of light between the safety and the
death of themselves and perhaps hundreds of their fellow-creatures. How
many of the 'missing ships' that have set forth in hope, with scores or
hundreds of souls on board, and never been heard of again, have gone
to their fate through the colour-blindness of the 'look-out,' who can
tell? How many disastrous railway collisions have been owing to the
same defect on the part of the engine-driver or stoker? The necessity
of a rigid examination of all men employed on our railways, in order
to ascertain their power of distinguishing the colours of the signals
upon which so many lives depend, is being recognised by the directors
and other officials. The same precaution ought to be adopted in the
case of sailors, and not only once, but frequently. Periodical tests of
their eyesight should be made at regular intervals; for in a physical
infirmity of this kind, so apt to be overlooked and remain unrecognised
even by those who are subject to it, lurk more dangers than in the lack
of many other strictly enforced requirements.
FOOTNOTES:
[A] Secondary colours are those which are formed by the combination of
any two of the three 'primary' colours; the combinations of secondary
colours are called 'tertiary' colours.
GOLD-MINE EXPERIENCES.
I was living some years ago in one of our North American provinces,
where, for several seasons, I was employed in constructing a railway,
which at the time I write is in liquidation, and which I shall call the
Swindleville Junction, a name, I trust, sufficiently expressive. The
climate did not suit me, neither did the natives; they were much too
'smart' for my fancy, and I was pretty generally always cheated in my
dealings among them. In one instance, however, I managed to save myself
from being tricked, but I am bound to say that it was from the clutches
of a Yankee that I made my escape, for I fully believe that a native
operator would never have given me a chance.
Gold had been discovered about thirty miles from the town of Radnor,
which was my headquarters, and the miners were making much money
by crushing the quartz. Of course the country was soon inundated
by prospectors, and numerous holes were opened with varying luck.
Curiously enough, the American element did not prevail much in the
district, the fact being that the provincials are more than a match for
an American even with his own weapons.
I happened, however, to fall in with one very impressive American, a
very pleasant plausible fellow. Captain Marcus Cyrus Duckett was his
name. He was a bit of a nautical dandy in his way. Blue surtout and
yellow waistcoat, large gold, watch-guard and a Panama hat, shortish
black trousers and Wellington boots, was his usual dress; and he was
more like an English coasting skipper than an American, being bluff
and stout, with a cheery red face and jolly manner. But I soon found
out that he was as great a desperado as was ever produced, in spite of
his off-hand appearance and rattling style. He had, he said, been a
blockade-runner, and had got safely in and out of Charleston eighteen
times during the civil war; and I heard hints that his success in
that trade was due principally to the fact of his having gained much
experience by eluding British cruisers on the coast of Africa, where he
had been long employed in command of a Spanish slaver trading to Cuba.
I used to meet this character occasionally at a village called
Bleakhausen, where I had frequently to go on business, which occupied
me a few hours; and rogue although he undoubtedly was, it was pleasant
to have a chat with him and hear him relate some of his adventures.
It was a great relief also to hear something else talked than the
everlasting drawl and snivel about pitiful election squabbles and
rates of freight, or prices of salt fish and molasses, which were the
only topics ever discussed among the semi-civilised natives in these
regions. By degrees we got pretty intimate; and one day the captain
informed me that he had discovered that a gold-bearing quartz vein ran
across the country in an easterly direction, and was now profitably
worked; that it passed right through a property near the village, which
he had been lucky in getting hold of very cheap, as all the timber
worth cutting on it had been sawn up, and the place was a barren rocky
clearing, full of half-burned stumps, and almost fit for nothing.
There were, however, the remains of a water-wheel and saw-mill on the
place, and a good fall of water. On these advantages Duckett laid
great stress, as useful to drive the quartz-crushing machines which he
intended to put up. He had sunk a shaft, he said, and run a heading
for some distance into the rock, and that it was looking very well,
although it had cost him 'a power of brass.'
I took little interest in all this, as I had often before had
prospecting schemes submitted to me, and had decidedly refused to mix
myself up with them, as my own business demanded all my attention. And
so speculators had at last ceased to trouble me. One day, however,
having longer to wait than usual at Bleakhausen, my horse being much
knocked up by a long journey, the skipper asked me to go and see his
mine, to pass the time. I agreed. So we took a walk of about a couple
of miles down to it. I was rather astonished when, after a disagreeable
tramp, we came to the place. It was no myth, for there it was in full
swing. The men seemed strangers, sailors they appeared, of various
nationalities; but comfortable shanties had been put up, and everything
seemed all right. A few pieces of the stuff were put in a bag by the
captain's wish, and sent to my wagon as specimens. After this, I drove
home, thinking nothing more of the matter.
One evening, a few weeks afterwards, I was reading a newspaper account
of the gold mines in the province, when it struck me that, as I
was going to the principal town next day, I would take one of the
Bleakhausen specimens, and have it analysed, just for the fun of the
thing, and see if there actually was any gold in it. I did not say
where it came from, that being unnecessary; but in a few days I got a
flattering analysis by letter, which also contained a small piece of
gold extracted by the assayer.
The next time Duckett met me he began to speak of his affairs, and
hinted that he was getting a little crippled for cash, and that the
millwright he had employed would not proceed with the repairs of the
mill or erect crushers without a heavy advance of money; so that, as
he had run himself nearly aground, he was reluctantly thinking of
abandoning the mine altogether.
I had been thinking over this quietly for a few weeks, when one evening
I had a visit in Radnor from the captain, who was much downcast, and
told me his creditors were so pressing that he could carry on no
longer, but must sell the estate for what it would fetch, to pay them
off; and with what balance he might have, would go to sea, and leave
the natives and their mines altogether. I was sorry for the fellow.
We talked long over the matter; and it ended by my becoming owner of
the property for ten thousand dollars, paid in railway bonds, which
Duckett said he could easily negotiate in the States; and I was to
retain him as overseer till the concern was in full working order, at a
salary and percentage on the output, which he solemnly assured me was
worth four ounces a ton; equal to nearly ten pounds a ton after paying
expenses. His estimate was slightly in excess of my experimental assay,
but not much; so I was well enough pleased with my bargain.
Things were going on pretty well under this arrangement, when one night
my groom appeared with a dreadful tale of being beaten by Duckett for
having declared the mine to be a humbug, and wishing I had not been
such an ass as pay him for it, and allow myself to be swindled by a
Yankee pirate. Whereupon the enraged mariner speedily made an example
of him. I began to suspect that it was just possible that Duckett _had_
imposed on me, in which case I should cut a poor figure every way.
The first thing to do was to satisfy myself that the specimen was the
actual produce of the mine; if not, the next thing was to get my bonds
back; by fair means, if possible; if not, by _any_ means; but in any
event to get quit of the Yankee at once. About two o'clock next morning
I saddled a horse myself without disturbing any person, and rode to
the mine, which I reached about five o'clock, and awoke the men in the
shanties. They were very unwilling to let me descend, as Duckett was
not there; but after some altercation, and seeing me very determined,
they gave me a lamp, and lowered me away. I was not down five minutes
when I discovered I had been done outright; the original specimen was
dark-brown coloured, and the stuff in the mine was dark-blue, and not a
trace of gold in it. The rascal had obtained the specimens from a mine
called Mount Benger, some miles away; and had played an old and common
trick--namely, placed the gold specimens among the rubbish, and then
picked them up before my eyes. As soon as I had fully satisfied myself,
I got back to the foot of the shaft; and to my great gratification,
was, on giving the signal, hauled to the top at once, just in time to
see Captain Duckett coming up the hill.
He was in a desperate passion at not having had notice of my visit;
but it was no part of my business to quarrel with him just yet. So I
soon managed to smooth him down with a story about my being restless,
and unable to sleep in the night, and thinking a sharp ride would do
me good, &c.; and I made him even believe that I was pleased, and more
than ever satisfied with my bargain. The captain took it all most
comfortably.
I asked him to breakfast at the inn; but he declined; agreeing,
however, to come afterwards to smoke and talk over matters, which he
did. After some cheerful talk, I hit on a scheme to recover my papers.
I agreed to lay a tramway to the mill from the mine, and requested him
to find some one to furnish us with timber for it; and he was to come
to Radnor on Tuesday and tell me what he had done, and also to meet an
engineer with whom I was in treaty to do the work at the water-wheel.
I called for my horse; but just as I was going to mount, I suddenly
turned round and said: 'Oh, by the bye, captain, Davis the lawyer was
saying yesterday that those bonds are of no use to you until they are
transferred by being indorsed and signed by me. I forgot to speak
about it just now; the tramway put it out of my head; but if you like,
I'll take them in with me and get Davis to do the needful; and you can
get them on Tuesday, when you are in.'
It was a bold stroke for the recovery of my bonds, but the bait took.
'All right,' said he; 'if you'll only wait half a minute, I'll fetch
them;' and away he went, and soon came back with the parcel.
I saw at once I was certain of my game; so, as the packet was a little
bulky, and did not go easily into my pocket, I said to him never to
mind it then, but to bring it to Radnor on Tuesday, and hand it to
Davis himself, which would be the safest plan; and that I would call on
Monday, and tell the lawyer to be ready for him--to which proposal he
smilingly assented; and with that I mounted, and trotted merrily home,
sometimes in the woods almost hallooing with delight. I called for
Davis, and told him that Duckett was coming to see him on Tuesday, and
the purpose of his visit, and that he was to take his instructions, and
I would see him in the course of the day, after Duckett had been with
him.
Davis was not noted for honesty; but he was the only limb of the law in
the place, and our firm had very frequently occasion for his services,
although we knew well enough that we could trust him no farther than
we could see him, and that he would hang his best friend, if he could
make ten cents by the job. So I did not incline to let him know the
exact state of matters till I had the bonds fairly in my own hand,
when I intended to ask his professional opinion on what I was going to
do--namely, to retain possession of them myself.
On Tuesday morning I set a young English boy, called 'the Nipper,' who
was in my employment, but was personally unknown to the captain, to
look out for him when he arrived, and to watch him all day, and keep me
posted up in his movements, and above all to let me know the moment he
traced him to Davis's den. In due time he announced to me in my office,
that Captain Duckett had arrived at Davis's door, and had actually
employed my spy to hold his horse, while he went in with a brown-paper
parcel, and shortly came out again, attended to the door by old Davis;
and the latest news was that he had put up at the hotel, and was then
very busy assisting to demolish a leg of lamb and pumpkin pie. Now was
my time; so I went up to Davis, and asked him to shew me the papers. I
compared them with a note of the numbers I had in my book, found them
all correct, and tied them carefully up and put them in my pocket; and
then proceeded to unfold the transaction to the lawyer, and ask his
advice as to whether I was legally authorised, under the circumstances,
to keep possession now that I had them. Moreover I told him he should
not lose his expected fees, as I would cheerfully pay them myself.
His opinion was that the law would bear me out; but that it was a
dangerous affair, as the pirate, as he called him, was a dreadful
character, and there was no saying what he might do. I quieted his
fears a bit and gave him twenty dollars, but he was still uneasy; and
as soon as I left him, he had his horse put to his wagon and went away
to the country, leaving word that he had been suddenly called from home
and would not be back for some days.
I went to the bank and had my bundle deposited in the safe; and after
that there was nothing more to do than to have the row with the captain
over; so my mind was easy, and I went home to luncheon. When I got back
to the office, I loaded a pair of heavy double-barrelled horse-pistols
which we used when travelling with money on pay-days, and laid them
in an open drawer in my writing-table, just to be handy in case of
accidents. I had scarcely written half a page of a letter, when Captain
Marcus Cyrus made his appearance in no very pleasant temper, and with
a face as red as the rising sun. He began by abusing Davis. 'He had
been to his house, and he was gone.' Where were his bonds? Did I know
anything of them? He would do this, that, and everything; and raged
like a demon.
I let him carry on for a while, and then I opened upon him and told
him what a wretch he was, and that I had fortunately discovered him in
time; that his mine was a swindle; that I would have him apprehended
as a thief and a rogue; and that I had the bonds safely locked up,
and he would never see them again; whereupon out came his revolver,
which in truth, I wondered he had not produced before, and with many a
high-sounding phrase he ordered me to give them up at once (thinking I
had them in the office-safe), or he would riddle me with his Colt.
I did not care much for all this, as a Colt is a very inferior weapon
to a brace of double pistols carrying ounce-bullets; so I snatched my
pistols, and jumped up and closed with him in a second, with one in
each hand, fully determined if he attempted to fire, to put an end to
his rascality for ever. He seemed rather astonished at the sudden turn
matters had taken, and did not appear to relish the look of the four
ugly tubes in such close proximity to his person; so he toned down more
easily than I expected, although he continued to growl like a bear with
a sore head. Ordering him out, I escorted him to the door, and saw
him go down-stairs, putting his pistol into his pocket and slamming
the doors behind him; and I cannot say I was sorry that matters had
passed off so quietly. However, it soon appeared that I was not to be
done with my gentleman just yet; in a short time my scout came to say
that he was away. He had gone to the stables for his horse; then he
lighted a cigar, all the while raging at everybody he came alongside
of; he then went to a hardware store, where the boy learned that he
bought a couple of cold-set chipping chisels, a hammer, a crow-bar,
and some small steel quarry-wedges, with which he drove off, as if
homeward-bound.