[CHAPTER XVIII]
A NEW THEORY
“Those robbers probably came in a light, rubber-tired rig, left it somewhere around the corner, got into the bank, did the job and drove away again,” was the opinion of Mr. Thompson, as he crawled out of the roof scuttle, followed by the boys.
“But how did they get to the roof?” asked Ned. “You’ve got to explain that.”
“Easy enough,” spoke the policeman. “You see this bank is in a row, with several other buildings, all about the same height. They could have climbed up the fire escapes, or they could have used a ladder. I’m inclined to the latter theory myself, for the fire escapes are on the front of the buildings, and if they went up them they’d be seen, whereas they could put a ladder up in back.”
The boys looked about them, and Bob took a couple of snap shots, including one of his two chums and the officer as they stood near the opened scuttle. As Mr. Thompson had said there was not much to see. The roof was a long one, extending over several buildings, and being flat, and covered with a composition of tar and gravel, alternating with tin on some of the structures, made quite a place to stroll about.
Jerry walked a little away from Ned and Bob, who were listening to Mr. Thompson’s explanation of how Detective Blake had discovered the finger marks in the dust around the scuttle rim, and had thus made his discovery.
“Blake thinks the scuttle was left unhooked, or else that the thieves reached in with a bent wire, and lifted the hook from the catch,” said the policeman.
The tall lad was walking over a stretch of tin roof, on a building two or three doors from the looted bank. There had been rain two days previous, followed by a brisk wind, which dried out the dust, and there was now quite a coating of the latter on the tin. There was also something else, and as Jerry caught sight of several marks in the dirt-coating he uttered an exclamation.