Still without openly showing our connection with MacLeod, Kennedy sought out the manager of the works, and, though scores of correspondents and reporters from various newspapers had vainly applied for permission to inspect the plant, somehow we seemed to receive the freedom of the place and without exciting suspicion.  Craig’s first move was to look the plant over.  As we approached it our attention was instantly attracted to the numerous one-story galvanized-iron buildings that appeared to stretch endlessly in every direction.  They seemed to be of a temporary nature, though the power-plants, offices, and other necessary buildings were very substantially built.  The framework of the factory-buildings was nothing but wood, covered by iron sheathing, and even the sides seemed to be removable.  The floors, however, were of concrete.

“They serve their purpose well,” observed Kennedy, as we picked our way about.  “Explosions at powder-mills are frequent, anyhow.  After an explosion there is very little debris to clear away, as you may imagine.  These buildings are easily repaired or replaced, and they keep a large force of men for these purposes, as well as materials for any emergency.”

One felt instinctively the hazard of the employment.  Everywhere were signs telling what not and what to do.  One that stuck in my mind was, “It is better to be careful than sorry.”  Throughout the plant at frequent intervals were first-aid stations with kits for all sorts of accidents, including respirators, for workmen were often overcome by ether or alcohol fumes.  Everything was done to minimize the hazard, yet one could not escape the conviction that human life and limb were as much a cost of production in this industry as fuel and raw material.

Once, in our wanderings about the plant, I recall we ran across both Garretson and Jackson in one of the offices.  They did not see us, but seemed to be talking very earnestly about something.  What it was we could not guess, but this time it seemed to be Jackson who was doing most of the talking.  Kennedy watched them as they parted.

“There’s something peculiar under the surface with those people at the boarding-house,” was all he observed.  “Come; over there, about an eighth of a mile, I think I see evidences of the latest of the explosions.  Let’s look at it.”

MacLeod had evidently reasoned that, sooner of later, Kennedy would appear in this part of the grounds, and as we passed one of the shops he joined us.

“You mentioned something about rumors of poisonous gases,” hinted Craig, as we walked along.

“Yes,” assented MacLeod; “I don’t know what there is in it.  I suppose you know that there is a very poisonous gas, carbon monoxide, or carbonic oxide, formed in considerable quantity by the explosion of several of the powders commonly used in shells.  The gas has the curious power of combining with the blood and refusing to let go, thus keeping out the oxygen necessary for life.  It may be that that is what accounts for what we’ve seen—­ that it is actual poisoning to death of men not killed by the immediate explosion.”