fulcrum to rest it on. But Archimedes was weak in that
point. He ought to have known that, even if he did get such a fulcrum,
he would still have required another world as long as his lever, to
enable him to walk out to the end of it. No, by the way, he might have
walked _on_ the lever itself! That did not occur to me before. He
might even have ridden along it. Come, that's a new idea. Let me see."

In order the better to "see," Mr Tippet dropt the piece of wood from
his left hand, and pressed his fingers into both eyes, so as to shut out
all earthly objects, and enable him to take an undistracted survey of
the chambers of his mind. Returning suddenly from the investigation, he
exclaimed:

"Yes, William, I don't quite see my way to it; but I can perceive dimly
the possibility of Archimedes having so formed his lever, that a line of
rails might have been run along the upper side of it, from the fulcrum
to the other end."

"Yes, sir," exclaimed Willie, who, having become excited, was entering
eagerly into his patron's speculations, and venting an occasional remark
in the height of his enthusiasm.

"Such a thing _might_ be done," continued Mr Tippet emphatically; "a
small carriage--on the galvano-hydraulic principle, of course--might run
to and fro--"

"With passengers," suggested Willie.

"Well--with passengers," assented Mr Tippet, smiling. "Of course, the
lever would be very large--extremely large. Yes, there _might_ be
passengers."

"An' stations along the line?" said Willie.

Mr Tippet knitted his brows.

"Ye-yes--why not?" he said slowly. "Of course, the lever would be very
long, extremely long, and it might be necessary to stop the carriages on
the way out. There might be breadth sufficient on the lever to plant
small side stations."

"An' twenty minutes allowed for refreshments," suggested Willie.

"Why, as to that," said Mr Tippet, "if we stop at all, there could be
no reasonable objection to refreshments, although it is probable we
might find it difficult to get anyone sufficiently enterprising to
undertake the supply of such a line; for, you know, if the lever were to
slip at the fulcrum and fall--"

"Oh!" exclaimed Willie, "_wouldn't_ there be a smash; neither!"

"The danger of people falling off, too," continued Mr Tippet, "might be
prevented by railings run along the extreme edges of the lever."

"Yes," interrupted Willie, whose vivid imagination, unused to such
excitement, had t