Another mode of action in this lake is to encrust nearly all the surface with the hardened covering, while active boiling is kept up at the margin on one side only. When this ebullition becomes intense, the fusion rises on that side, while the other side is quiet. After a little, this agitated lava will rise and fall over upon the crust, pressing or breaking it down, and rolling in a fiery wave across the lake, and thus covering its whole surface with an intense boiling and surging, so fierce and so hot that the spectator withdraws from the insufferable heat to a cooler and safer position. To be struck with this heat in its intensity, is to be death-struck, and to inhale a full draught of this sulphurous acid gas in its strength would be to extinguish life. All visitors must keep on the windward side of the lake and avoid all currents of hot steam and gases.
Some visitors are too daring.
Others are too timid. And I have seen ladies tremble and almost faint on going down into the crater while yet a full mile from any visible fire. One who was in my charge was so terrified that no assurance of safety and no effort to persuade could move her. She sat down upon a rock a mile from Halemaumau, and would not move until we led her out of the crater. Others, though transfixed and awe-struck at first, become so fearless that they play with the pools and little rills of lava, dipping up specimens of it to take away.