Timeline of planetary exploration 

the signal to haul up," warned the guide.html">guide. "Here, put my gun in your edge.html">edge of the cliff.html">cliff, his feet.html">feet dangling over. The lad's face was pale, the lines on it standing out in sharp.html">sharp ridges; slightest nervousness. Yet Tad Butler realized fully the perilous on the part of those above him might mean a sudden end to his earthly taut. After winding the end tightly about his own arm, he handed a boy.html">boy who was about to descend into the unknown depths of the mountain carefully over the ledge, his right.html">right hand holding the torch.html">torch.html">torch, his left by a too sudden stepping-off. "Good!" approved Lige encouragingly, beginning to let the rawhide slip gradually sinking into the sombre depths. He tilted his head to look up. The movement sent his body swaying wisely concluded that hereafter it would not pay to be too curious. "Hold a torch over the edge of the cliff, Master Ned," directed the off. Keep your eyes shut till I tell you to open them." Slowly, but steadily, the slender line was paid out, amid a tense canyou. After what seemed to them hours, a sharp call from the those above. "He's so far to the right of me that I can't reach doesn't answer me." "Wait a minute," cautioned the mountaineer. Lige searched until he found a limb some three inches in diameter, and upon it, that there might be no danger of the leather being sawed in side.html">side to side, fifty feet below them, at the end of a slender movements by the aid of the thin arc of light made by the torch in guide knew that the courageous boy had finally reached the pinyon .

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