A heavy stratum of tarlike smoke formed above the fire as it toned down. Presently this black stratum was uplifted near the centre and then pierced with a stupendous geyser of yellow flame, which reddened as it fused and tore through the tarry smoke and then gushed astonishingly high above. A year or two prior to the fire a snow slide from the heights had smashed down into the forest. More than ten thousand trees were mowed, raked, and piled in one mountainous mass of wreckage upon some crags and in a narrow-throated gulch between them. This wood-pile made the geyser flames and a bonfire to startle even the giants. While I was trying to account for this extraordinary display, there came a series of explosions in rapid succession, ending in a violent crashing one. An ominous, elemental silence followed. All alone I had enjoyed the surprises, the threatening uncertainties, and the dangerous experiences that swiftly came with the fire-line battles of this long, smoky war; but when those awful explosions came I for a time wished that some one were with me. Had there been, I should have turned and asked, while getting a better grip on my nerves, "What on earth is that?" While the startled mountain-walls were still shuddering with the shock, an enormous agitated column of steam shot several hundred feet upward where the fiery geyser had flamed. Unable to account for these strange demonstrations, I early made my way through heat and smoke to the big bonfire. In the bottom of the gulch, beneath the bonfire, flowed a small stream; just above the bonfire this stream had been temporarily dammed by fire wreckage. On being released, the accumulated waters thus gathered had rushed down upon the red-hot rocks and cliffs and produced these explosions. In the morning light this hanging terraced garden of yesterday's forest glory was a stupendous charcoal drawing of desolation. Insects in the Forest Insects in the Forest The big trees of California are never attacked by insects. This immunity is extraordinary and may be the chief characteristic that enables these noble trees to live so long. Unfortunately it is not shared by other species. The American forests are infested with thousands of species of injurious and destructive insects. These insects, like the forest fires, annually kill numerous forest areas, and in addition leave millions of deformed and sickly trees scattered through the living forest to impair and imperil it. After some general tree studies which have occupied odd times for years and extended through the groves and forests of every State and Territory in the Union, the conclusion has been forced upon me that the forests are more widely wasted by insects than by fire.