"Well, the doctor said it was and so did some of the fellows," said Arthur; "so we cannot say anything."

"Did they tell you about this gully?" asked Jack, who had gone ahead a few paces, and paused in front of a deep gully stretching right across their path, and presenting an obstacle which there seemed to be no way of getting over.

The gully was quite wide in front of them, and to the left extended into the woods as far as they could see, while on the right it presently ended at a great ma.s.s of ledge rock, which towered well above their heads, and was crowned with trees, some of them very big, while at different points, as far as the bottom, there were trees of various sizes growing from crevices in the rock.

"H'm! I guess they did not know about this," muttered Percival. "This gully can be bridged all right, and it will be a nice job for us; just the sort I like, but in the meantime, how are we going to get over and go on with our exploring?"

"You ought to know that," laughed Billy Manners. "You are an engineer, you know. A little thing like that ought not to bother you."

"Well, it does all the same," said Percival with some impatience, as Billy took the black box from under his arm. "What are you going to do now, you funny fellow?"

"Take a picture of that ledge," said Billy, looking around for a flat rock or a stump upon which to place his box.

"Wait a minute till we get back," said Blaisdell, who had joined Jack at the gully. "It looks to me as if there was a cave down there. There is some sort of an opening at the bottom of the ledge, seems to me."

"Yes, so there is. I never noticed it before. How are you going to get a picture, Billy? That is no camera you have. Where is your lens?"

"Haven't any! I can take a picture without a lens, only it will require more time to make the exposure."

"Take a photograph without a lens?" said Percival in a tone of doubt, mixed with scorn. "You must be crazy!"

Several of the boys thought the same as d.i.c.k, and laughed heartily at what they considered one of Billy's harum scarum schemes.

"Go ahead and laugh, boys," said the good-natured fellow, as he placed his small square box on top of a flat rock he had found, and pointed it toward the ledge at the foot of which Blaisdell had discovered his supposed cave entrance. "I know something that you fellows do not, and I am going to get a picture. The light is fine, for it just sifts nicely through the trees, and the sun is quite high enough yet."

"Yes, but Billy, if you have no lens nor shutter, how are you going to take a photograph?" asked Blaisdell. "That doesn't look like anything but a square box."

"That is all it is, but it is a camera just the same. Did you never hear tell of a pinhole camera, my boy?"

"No, I did not. What is it?"

"I have a plate in this box, and it is set at what they call a universal focus. That is, I can take a picture of something not too close, and one at a distance. The box is lined with black paper, and in front there is a very small hole, now covered by a flap of the same stuff. This hole will admit the light fast enough, and yet not too fast, and as my plate is sensitized, I can get a picture even if I have no lens. Did you ever see a 'camera obscura,' as they call them?"

"Oh, you mean one of those things that take a panoramic view of the beach and everything in sight? People get shown up sometimes when they don't know it."

"Yes, that's the thing. You don't get a real photograph there, but you see everything shown up on a table, as the thing at the top revolves.

Well, I will get a picture with my pinhole camera even if I have no lens. Why, they used to sell these things, maybe they do yet."

"Why, yes, seems to me I have seen something about them in the advertis.e.m.e.nts."

"No doubt," and Billy, having seen that his out-of-the-way camera was perfectly level, carefully removed the black flap from the tiny hole in the front of the box and said:

"That's all right. You fellows cannot get in front of it, and so there will be no harm done. It will take some time to get a picture, but I will have it all the same. The light is fine and I can afford to wait."

"There's a cave down there all right, d.i.c.k," said Jack. "Don't you think so?"

"Yes, it looks like a cave," said Percival. "How would you like to go down and explore it?"

"All right, if we can manage it. Got a light? We can make torches I suppose. There is plenty of pine wood about. Anyhow, I have my pocket flash with me."

"You fellows can go down there if you like," laughed Arthur, "but none of it for me."

"Or for me either," said Harry.

"Come on, d.i.c.k," said Jack. "Here is a good place to get down, I think."

The two boys supplied themselves with stout sticks with which to aid them in getting down, and then began to make the descent, the other boys sitting or standing around.

Step by step, from rock to rock, and from one tree root to another the two chums made their way down into the gully and toward the hole in the face of the ledge, which they could at length see was of considerable depth, and high enough for them to pa.s.s through without stooping.

They finally reached the bottom, and then were not far from the hole into which they made their way, finding that it extended for some distance at an incline part of the way, and then on a level, as it seemed.

"There are lots of these holes in the Hudson valley," said Jack, "and sometimes they are interesting, while at other times they are nothing but holes, don't go very far, and have nothing in them after all."

"You don't expect stalact.i.tes or anything of that sort, do you, Jack?"

asked d.i.c.k.

"No, for this is not a limestone region, like that in Kentucky or in Virginia, where there are some of the famous caves. However, it will be worth our while to go down here, I think, or I would not have undertaken it. We do not need to go very far. This place may be known, although the people in the woods hereabout don't take much stock in such things, as they say and think tourists and summer boarders who want to explore them just a lot of crazy fools."

"It's an easy thing to call a man a fool because he can understand or like things that you don't," laughed d.i.c.k.

The boys at length got so far into the hole in the rocks that they had to make use of Jack's pocket electric torch, and they proceeded, still on a down grade, and finding the way a bit rough in spots, but at last finding it better traveling and more level.

They had turned somewhat, and looking back, could not see the entrance where they had come in, nor the gully beyond, nor any light, Percival saying with a bit of a shudder:

"H'm! it is a bit creepy in here, isn't it, Jack?"

"Oh, I don't know," laughed Jack. "I think other people have been here before us, d.i.c.k. I can see black spots on the rock overhead, as if smoke from torches had made them. Then the rock under our feet is worn somewhat. Some one has been in here before, although not recently."

"H'm! you notice everything, as Ken Blaisdell said just now," laughed Percival. "Does anything escape your notice?"

"Well, d.i.c.k, I have had to keep my eyes about me pretty much all of my life in order to make my way, and I suppose it has got to be a habit, but am I any more observant than most boys? They say that little children notice everything, certainly a good deal more than their parents like, sometimes. Perhaps I have not gotten over my childish habits."

"Oh, I don't believe you were one of those young nuisances that call attention to everything, the grandmother's wig, the maiden aunt's false teeth and the like," chuckled Percival. "Yes, I think you are particularly observant and--h.e.l.lo! what's that?" as a dull sound broke upon their ears.

"It might be thunder," said Jack. "It sounds somewhere behind us. That's all right. This place begins to look interesting, d.i.c.k. Suppose we go on."

The floor of the cave was quite level here, and the place wider and higher than before, so that it was really much more a cave than a mere hole in the ground, and the boys pushed on, having plenty of light from Jack's torch, and being in no danger of stumbling or falling.

They pushed on for a few hundred feet, and then came upon a narrow pa.s.sage where they at first thought the cave ended.

Jack flashed his light ahead of him, and saw that there was evidently a chamber beyond the pa.s.sage, and in a few moments they came out in it, and, to the amazement of both, saw a rude table and a bench, and on the floor some old clothes, a black mask or two, some burglars' tools and a coa.r.s.e sack.

"h.e.l.lo! here's a discovery, Jack," cried Percival. "I shouldn't wonder if this was some more of the plunder taken by the man with the white mustache and his accomplices."

"It certainly looks like it," said Jack, examining the sack and finding nothing in it; "but it strikes me that I can see a light ahead of us.

Suppose we go on."

"All right," agreed d.i.c.k, and Jack led the way forward.