Iceland: Horseback tours in saga land

by W. S. C. Russell

This place is marked on the map of Iceland as Geysir. The word is from the verb geysa, “to rush forth furiously, to burst out with violence.” It is not applied to all the spouting springs of boiling water as is geyser, the geological term, but is the name of the king of all the spouting springs in Iceland. Scores of these springs are located in this place but each has a special name which is appropriate to some physical peculiarity, such as Strokr, the churn, the tube where the water rises, falls and boils vigorously as the cream rose and fell with a frothy splutter in the ancient dash churn. When we think of the geysers of New Zealand, the Yellowstone National Park or any place in Iceland we must remember that they took this name from Geysir. There is only one Geysir.

The area dominated by the springs is directly at the foot of Laugarfell, indeed the south side of this mountain once formed a portion of the hot section. This portion of the mountain is void of every trace of vegetation, it is marked by ruined geyser mounds, smeared with sticky clay of many colors, punctured with tiny fumaroles whence issue wavering wands of steam, while in many places rivulets of hot water break through the pasty crust. The area of real activity is about 3,000 feet by 1,800 feet. The place is strewn with fragments of geyserite and bits of wood, straw and metal, thinly encrusted with the mineral deposit from the springs. Cast a stick, a straw or a bit of paper where the spray will fall on it and in a day it will have become petrified and cemented to the rock beneath. The entire substratum is intensely heated, the ground is in a constant tremor which often accelerates to a gentle quake. Far down below these hissing, silicious tubes there is unknown latent heat. For ages the thermal capacity of this place has been sufficient to eject untold millions of tons of superheated water, at frequent intervals, in large installments from these stupendous safety valves.

We roamed over the section several times with our attention always fixed on Geysir and ready at the slightest warning to dash madly towards it should it condescend to favor us with a manifestation of its power. In the meantime we plugged the tube of a little geyser with turf and then stood aside to listen to the heavy gurgle of reproach which rattled in its throat and to witness the vomiting of boiling water to a height of twenty-five feet. As soon as it got relief we plugged it up again and as often as we administered the turf so often did it eject it. It was midnight and Mrs. Russell had long since retired, but the weirdness of the place held sleep aloof from my eyes. In company with a German I wandered over the area again, stood on the rim of Geysir to watch our shadows in its depths hoping for the occasion to arise for us to chase those shadows headlong up the mountain slope. We returned to the little spouter and played like a couple of boys. As a parting shot we decided to give it an extra amount of turf and to ram it down the barrel with a pole. We did this with so much success that we waited long for the discharge but there was none. We had loaded it too well. The tube of our gun was too strong to burst, the wadding was packed too tightly for the powder to blow it out. Silently we sat by it for an hour when my companion said,—

“Geyser schlaft.”

To which I replied,—“Ich will schlafen.”

The day after the following it burst out with a fine jet of water at six in the morning and spouted without interruption till nine when we rode away. As we passed over the ridge we looked back and the last sight we had of this place was the top of a column of water pouring from this tube. The extra charge of turf was well worth the trouble.

Morning came but Geysir had not erupted. Its surface betrayed no signs of past disturbances and gave no promise for the future. From the neighboring farms we collected seventy pounds of bar soap which we cast into the center of the basin, where it immediately sank. We were told that during the day there would certainly be an eruption. The soap is kept here expressly for sale for this work. Ask an Icelander what the agency of the soap is and he will reply,—

“I do not know, it always does it and does it thoroughly.” I venture the following explanation. Recalling that the accepted idea of the interior of a geyser is that of a large chamber of heated rock nearly filled with water and that below the water line there is a tube which bends down then upward into a chamber in the rock. The water becomes superheated. The steam and other gases in the dome of the chamber are under terrific pressure on account of the great heat and the weight of the column of water above, (if one thinks of the geyser tube connecting the underground basin with the surface as the letter J). When the pressure in the dome over the water becomes greater than the downward force of the water in the long arm of the tube then there is an upward movement through the tube. The expanding steam throws out some of the water. This reduces the pressure on the superheated water in the basin and some of the water bursts into steam to continue the action. This process goes on till basin, tube, underground chamber and connecting tubes are empty. Distant and cooler underground waters now rush in freely to refill the system and time produces a repetition. It is easy to construct glass apparatus in the laboratory to demonstrate this phenomenon. But what of the soap? This substance is composed of materials which quickly break down into hydrocarbon gases and increase the pressure in the chamber, just like oil spurted into the superheater of a water gas machine.

Many of the boiling springs, spurting jets and fumaroles are alike in this locality but three of them deserve special notice.