National Geographic : 1939 Oct
516 THE NATIONAL GEOGRAPHIC MAGAZINE Photograph by Jean Verhoogen LAVA SHEETS BUILD UP A TORTOISE-SHELL BACK FOR NYAMLAGIRA The lava, exceedingly fluid, spreads out thinly. The sheets pile up on each other as they cool, assuming a peculiar shape. This type is known to geologists as a "shield volcano" (page 526). Photograph by G. Michel A ONE-MAN "BUTTERFLY NET" BRINGS IN PLENTY OF FISH ON LAKE KIVU Suddenly applying pressure on the ends of the two poles, the fisherman raises the submerged net in a jiffy, trapping all the fish between the mesh and the surface of the water.