We strolled around the east side of the lake to the north shore and for three days made our headquarters at _Reykjahlið_, Smoking-Pass, a remnant of a once prosperous farm which has been destroyed by the lava pouring from the vents of the foot hills that surround _Leirhnúkr_. English travellers of casual observation have stated that this great flood of lava came from the volcano itself but if they had taken the trouble to follow the streams of lava from the farm to their source, they would have found that a deep valley runs between these foothills and the real volcano of _Leirhnúkr_. This lava flowed during the years 1725, 1727, 1728 and 1729. _Leirhnúkr_ was active at the same time, hence their error in attributing this sheet of lava to the volcano. The volcano has enough havoc to its discredit without charging it with the crime of ruining the fertile plains at the north end of the lake. In 1729 an extensive tract of grazing and mowing land of rare fertility was overflowed by molten rock. Some branches of the stream entered the lake and quenched their ardent fires, one branch flowed to the northeast corner of the church and was arrested in its flow within two feet of the building. Here the stream divided into two arms and flowed around the edifice reuniting about sixty feet from the opposite corner, leaving the church entirely unharmed in the midst of the terrific heat of its fiery glow. Says Henderson, who mused at length over the incident,— “Who knows but the effectual earnest prayer of some pious individual, or some designs of mercy, may have been the cause fixed in the eternal purpose of Jehovah for the preservation of this edifice?” On this same farm, and at some distance from the margin of the lake, there is a deep rift in the plain, the descent into which is made with little difficulty. There is an abundance of water in the rift at a temperature of 90°F. The place is called _Stórigjá_, Large-Rift, and is a result of prehistoric earthquake action. The rift is very deep and extends up near to the hot mountain from whence issues the hot water. The water in the bed of the chasm is clear as crystal and reflects most beautifully the narrow streak of sky and the flower encrusted walls. Here the wild geranium and ferns grow abundantly, almost tropically, on the walls and in the clefts of the rocks. It was a novel experience to take a swim deep down in the crust of the earth in this hot water of emerald hue, to look up the chasm and see the towering ridges wreathed with rising steam and then to turn about and gaze towards the snow-capped peaks beyond the other end of the rift. The bath is invigorating and puts vigor and elasticity into the body to such a degree that it is noticeable for hours afterwards. It has been thought to be strongly radio-active.