not trust
either of them alone, but together they are invincible. Good-night,
children. I wish you success, Dick," as he turned away.

Seaton took a lover's leave of Dorothy, and went into the lawyer's
study, taking an envelope from his pocket.

"Mr. Vaneman," he said in a low voice, "we think the Steel crowd is
still camping on our trail. We are ready for them, with a lot of stuff
that they never heard of, but in case anything goes wrong, Martin has
written between the lines of this legal form, in invisible ink A-36,
exactly how to get possession of all our notes and plans, so that the
company can go ahead with everything. With those directions any chemist
can find and use the stuff safely. Please put this envelope in the
safest place you can think of, and then forget it unless they get both
Crane and me. There's about one chance in a million of their doing that,
but Mart doesn't gamble on even that chance."

"He is right, Dick. I believe that you can outwit them in any situation,
but I will keep this paper where no one except myself can ever see it,
nevertheless. Good-night, son, and good luck."

"The same to you, sir, and thank you. Good-night."

+--------------------------------------+
| |
| _The author of this story, being a |
| chemist of high standing and an |
| excellent mathematician, gives us a |
| rare gem in this interplanetary |
| tale. For one thing, he suggests an |
| interesting use of the action of |
| acceleration. In this instalment it |
| is made to take the place of gravity |
| when the interplanetary vehicle is |
| out in open space. In order to get |
| the gravity effect, a positive or |
| negative acceleration could be given |
| out. |
| |
| This instalment retains its easy |
| flow of language and continues to |
| develop surprise episodes with a |
| remarkable degree of realism._ |
| |
+--------------------------------------+

CHAPTER VIII

Indirect Action

The afternoon following the homecoming of the Skylark, Seaton and
Dorothy returned from a long horseback ride in the park. After Seaton
had mounted his motorcycle Dorothy turned toward a bench in the shade of
an old elm to watch a game of te