"I felt angry at having been tricked by so elaborate a story as
that which he had told me. 'I was admiring your fuller's-earth,'
said I; 'I think that I should be better able to advise you as to
your machine if I knew what the exact purpose was for which it
was used.'
"The instant that I uttered the words I regretted the rashness of
my speech. His face set hard, and a baleful light sprang up in
his grey eyes.