National Geographic : 1940 Jun
WHERE HOT POOLS SEETHE AND GEYSERS S;OUT i auuonai kieograpnic societyy ol'(lacnromne y IdlWin I.. \\ lslert A HUNDRED ANI) FIFTY FEET OR MORE RISES OLD FAITHFUL IN ROBES OF STEAM Queen of the Yellowstone is this wonderful geyser, which has been erupting night and day, winter and summer, ever since its discovery in 1870. To the millions who have watched Old Faithful shoot forth her ten to twelve thousand gallons of scalding water on an average of every 661 minutes, her regularity is a byword. But you can't actually " set your watch by Old Faithful." On occasion she has waited 82 minutes or has beaten the gun by nearly half an hour. Eruptions last about four minutes.