application was that I was seized with an illness. For some months I
had incessant headache; my hair became dried up, then turned grey, and
finally came off. Weighing myself shortly after my recovery, at the
age of fifteen, I found that I just balanced fifty-six pounds. I took
up mensuration, then astronomy, working at them slowly, but giving the
bulk of my spare time to chemistry.

"In the year 1869, when I was sixteen years old, I came across Cuthbert
Bede's book, entitled 'Photographic Pleasures.' It is an amusing book,
giving an account of the rise and progress of photography, and at the
same time having a good-natured laugh at it. I read the book
carefully, and took up photography as an amusement, using some
apparatus which belonged to my father, who had at one time dabbled in
the art. I was soon able to take fair photographs. I then decided to
try photography as a business. I was apprenticed to a photographer,
and spent four years with him--one year at Northallerton, and three at
Darlington. When my employer removed to Darlington, I joined the
School of Art there.

"Having read an account of the experiments of M. E. Becquerel, a French
savant, on photographing in the colours of nature, my curiosity was
awakened. I carefully repeated his experiments, and convinced myself
that he was correct. I continued my experiments in heliochromy for a
period of about two years, during which time I made many photographs in
colours, and discovered a method of developing the coloured image,
which enabled me to shorten the exposure to one-fortieth of the
previously-required time. During these experiments, I came upon some
curious results, which, I think, might puzzle our scientific men to
account for. For instance, I proved the existence of black light, or
rays of such a nature as to turn the rose-coloured surface of the
sensitive-plate black--that is, rays reflected from the black paint of
drapery, produced black in the picture, and not the effect of darkness.
I was, like Becquerel, unable to fix the coloured image without
destroying the colours; though the plates would keep a long while in
the dark, and could be examined in a subdued, though not in a strong
light. The coloured image was faint, but the colours came out with
great truth and delicacy.

"I began to attend the School of Art at Darlington on the 6th of March,
1872. I found, on attempting to draw, that I had naturally a correct
eye and hand; and I made