t to the light as you
suggest, _the film upon development would have come out black! But it is
quite transparent!_" I replied in triumph.

My retort floored the Court. We were dipping into matters about which
they were completely ignorant. There was a hurried whispering and then
the Chairman commented:

"We'll soon prove that you are wrong!"

Proceedings were suspended. A clerk left the room to return a little
later with a civilian who proved to be a photographer in Wesel.

The problem was presented to him, but I saw at once that he knew nothing
whatever about the chemistry of photography. He was turned over to me
for cross-examination, and within three minutes I had so pulverised his
statements that he was quite bewildered, and he left the Tribunal with
his photographic reputation sadly shattered.

Another witness was summoned, the Court being determined to get at the
bottom of the problem which had been raised. They certainly recognised
the significance of my contention. This time it was a military officer.
He was examined by the Court, and then I was given the liberty to
cross-examine. My very first question was adequate to satisfy myself
that he knew even less about the subject than the previous witness. But
he was nervously anxious not to betray his ignorance. He had been called
in as an expert and fervently desired to maintain this reputation. He
did so by acquiescing in every statement which I put to him concerning
the action of light upon nitrate of silver.

"Now," I asked emphatically, when I had completely caught him, "under
these circumstances, and according to what you have been explaining to
the court, the second half of this film which is transparent has never
been exposed?"

"It has not."

His negative was so emphatic as to convince the Court. I had scored the
crucial point and felt, now my supreme difficulty had been subjugated so
conclusively, that all was plain sailing. It was only too evident that
everything had turned upon that short length of unexposed film, and I
felt devoutly thankful to Providence that the light had not accidentally
penetrated to the sensitised surface. Had the unexposed section been
black my fate would have been irrevocably sealed.

Now I was asked to present my defence.

"Can you give us a complete and detailed narrative of your journey, say
from the time you left Brighton by the 5.10 p.m. train, on Saturday,
August 1, up to your arrest."

I nodded affirmatively.