“That’s right,” said his chum.  “It will be a new experience for us.  Not quite so much jungle, I hope, as the dose we had of it when we went after the wild animals.”

“No, and I’m glad of it,” responded Joe.  “That was a little too much at times.  Yet there is plenty of jungle in Panama.”

“I suppose so.  Well, suppose we go up on deck for a breath of air.”

They had taken a steamer that went directly to Colon, making but one stop, at San Juan, Porto Rico.  A number of tourists were aboard, and there were one or two “personally conducted” parties, so the vessel was rather lively, with so many young people.

In the days that followed Joe and Blake made the acquaintance of a number of persons, in whom they were more or less interested.  When it became known that the boys were moving picture operators the interest in them increased, and one lively young lady wanted Blake to get out his camera and take some moving pictures of the ship’s company.  But he explained, that, though he might take the pictures on board the steamer, he had no facilities for developing or printing the positives, or projecting them after they were made.

In the previous books of this series is described in detail the mechanical process of how moving pictures are made, and to those volumes curious readers are referred.

The process is an intricate one, though much simplified from what it was at first, and it is well worth studying.

On and on swept the Gatun, carrying our friends to the wonderland of that great “ditch” which has become one of the marvels of the world.  Occasionally there were storms to interrupt the otherwise placid voyage, but there was only short discomfort.

Mr. Alcando was eager to reach the scene of operations, and after his first enthusiasm concerning the voyage had worn off he insisted on talking about the detailed and technical parts of moving picture work to Joe and Blake, who were glad to give him the benefit of their information.

“Well, you haven’t seen anything more suspicious about him; have you?” asked Joe of his chum when they were together in the stateroom one evening, the Spaniard being on deck.

“No, I can’t say that I have.  I guess I did let my imagination run away with me.  But say, Joe, what sort of a watch have you that ticks so loudly?”

“Watch!  That isn’t my watch!” exclaimed his chum.

“Listen!” ordered Blake.  “Don’t you hear a ticking?”

They both stood at attention.

“I do hear something like a clock,” admitted Joe.  “But I don’t see any.  I didn’t know there was one in this stateroom.”

“There isn’t, either,” said Joe, with a glance about.  “But I surely do hear something.”

“Maybe it’s your own watch working overtime.”

“Mine doesn’t tick as loud as that,” and Blake pulled out his timepiece.  Even with it out of his pocket the beat of the balance wheel could not be heard until one held it to his ear.