"This," continued Edmund, unabashed, "is more dreadful than Roger
Bacon's powder;" and pulling out a short, stout iron canister, he
poured some crystals into a hole. "Look and behold," he added. "I
invoke no saints, nor do I seek the aid of any deity, but see;" and
rolling some of the crystals tightly up in some parchment, he dropped
it into the midst of the fire.

For a few moments nothing was seen or heard of it, and the onlookers
were smiling to each other when the wonderful crystals began to
splutter and fizz, till the packet suddenly exploded with a loud
report, rattling the bottles and jars together, while the rumbling
report rolled up the long subterranean passage.

"Ha!" exclaimed Edmund, triumphantly. "You shudder at the sight; that
is nothing, I can do infinitely more than that. I will do it with more
crystals now."

"Nay, we are convinced of thy prowess; when the fumes have cleared
away, show us this engine," replied Manners. "It is full of wheels;
show us their purpose."

"That shook this chamber," Edmund replied, "but this could well nigh
shatter it."

"Great man, we acknowledge thy mighty genius," responded Sir Ronald.
"Reveal the limit of thy powers."

"I will," said Edmund, enthusiastically, "I will."

All his reserve was worn off now, and he expatiated at length upon the