managed to thrust the
doctor aside and start toward the door. His seriousness impressed me
so that I gave him a supporting arm and together we headed down the
hall, with Mrs. Drayle and the doctor following anxiously in the rear.
The laboratory was deserted and locked when we arrived. The police
evidently felt it was too uncanny an atmosphere for a prolonged wait.
Drayle opened the door, went directly to his machine, and examined it
minutely.

"'Thank the Lord that woman hit only me!' he said, and sank into a
chair. Then he asked for some brandy. Mrs. Drayle rushed off and
reappeared in a minute with a decanter and glass. Drayle helped
himself to a swallow that brought color to his cheeks and new strength
to his limbs. Immediately after he turned again to the machine. I
dragged up a chair, assisted him into it, and seated myself close by.

"I knew little enough about mechanics, but I was fascinated by the
numerous gauges that faced me on the gleaming instrument board. There
were dials with needlelike hands that registered various numbers;
spots of color appeared in narrow slots close to a solar spectrum: a
stream of graph-paper tape flowed slowly beneath a tracing-pen point
and carried away a jiggly thin line of purple ink. In a moment Drayle
was oblivious of everything but his records. I watched him copy the
indicated figures, surround them with formulas, and solve mysterious
problems with a slide-rule.

"His calculations covered a large sheet before he had finished. At
last he underscored three intricate combinations of letters and
figures and carried the answers to his private radio apparatus. This
operated on a wave length far outside the range of all others and
insured him against interference. With it he was able to speak at any
time with his assistants in Washington or Boston or with both at once.
He threw the switch that sent his call into the air. An answer came
instantly, and Drayle begin to talk to his distant lieutenants.

* * * * *

"'We've been interrupted, gentlemen,' he said, 'but I think we may
continue now. We'll reassemble in the Boston laboratory. Have you
arranged the elements? The coefficients are....' And he gave a
succession of decimals.

"A voice replied that all was ready. Drayle said 'Excellent,' went
back to his invention and twisted a black knob on the board before
him.

"With this trifling movement all hell seemed to crash about us. The
ghastly caco