Straining our eyes to look along the reach of level railway which stretched away through the pine barren, we began to see certain ominous puffs of smoke, which might indeed proceed from some fire in the woods, but were at once set down by the men as coming from the mysterious locomotive battery which the Rebels were said to have constructed. Gradually the smoke grew denser, and appeared to be moving up along the track, keeping pace with our motion, and about two miles distant. I watched it steadily through a field-glass from our own slowly moving battery: it seemed to move when we moved and to halt when we halted. Sometimes in the dim smoke I caught a glimpse of something blacker, raised high in the air like the threatening head of some great gliding serpent. Suddenly there came a sharp puff of lighter smoke that seemed like a forked tongue, and then a hollow report, and we could see a great black projectile hurled into the air, and falling a quarter of a mile away from us, in the woods. I did not at once learn that this first shot killed two of the Maine men and wounded two more. This was fired wide, but the numerous shots which followed were admirably aimed, and seldom failed to fall or explode close to our own smaller battery. It was the first time that the men had been seriously exposed to artillery fire,--a danger more exciting to the ignorant mind than any other, as this very war has shown.[D] So I watched them anxiously. Fortunately there were deep trenches on each side the railway, with many stout projecting roots, forming very tolerable bomb-proofs for those who happened to be near them. The enemy's gun was a sixty-four-pound Blakely, as we afterward found, whose enormous projectiles moved very slowly and gave ample time to cover,--insomuch, that, while the fragments of shell fell all around and amongst us, not a man was hurt. This soon gave the men the most buoyant confidence, and they shouted with childish delight over every explosion.