190 12 



main points, in agreement; in several places, however, there are insignificant dis- 

 agreements which show that the springs have undergone some change since 1888. 

 In the following remarks concerning the individual springs, particular attention 

 has been paid to these changes, and I must refer those who desire more detailed 

 information as to the external characteristics and appearance of the s])rings, to the 

 previously mentioned treatise by Thoroddsen in the Swedish periodical "Ymer". 



No. 1 has a temperature of 11" C, instead of 64"^ according to {>. Thoroddsen. 

 In this spring the temperature is dependent on the place where the measurement 

 is taken. On the surface at several places it was only 64°, so that it is quite pos- 

 sible that the great difference in the records of temperature can be explained by 

 the fact tliat each record refers to a different place in the spring. The highest 

 temperature we found in that spring was 77°. Nr. 5 is a mud spring which throws 

 mud incessantly to a height of 1 m. The temperature was 95°. This spring seems 

 to be more active than in 1888, whereas the small mud holes No. 3 have dis- 

 appeared from the surface. Nevertheless feeble exhalations of steam through cracks 

 in the surface, indicate that the activity of the spring is continuing deep down, 

 though probably with diminished vigour. From No. 2 we took some sample 

 gases, Hveravellir No. 2. 



The springs Nos. 4- S can now practically be reckoned as extinct springs, at 

 least they remained quite inactive as long as we were at Hveravellir. No. 9 is still 

 an active spring, although its energy seems to be declining. No. 10 has also under- 

 gone some change; in 1888 it consisted of three holes; of these one has disappeared, 

 probably the most northerly. The most southerly hole is the most active, and it has 

 periodic eruptions, during which the water is thrown to the height of about 1 ft. (3 dm.). 

 In 1888 the eruptions were more frequent, and the water was then 90°— 95°, now 

 it is only 84°. Around the hole in the basin of the spring, through which the 

 gases are emitted, there was a yellow border of sulphur. We took sample gases 

 from the north-western hole, in which the temperature was 77°, — Hveravellir No. 10. 

 No. 11 has far less frequent eruptions now than in 1888; its temperature is .81°, 

 and 91° during an eruption. No. 12: the basin is generally quite dry, but occa- 

 sionally it is filled with hot water, accompanied with weak gaseous emissions. 

 The temperature was 86°, but on another occasion it was only 56° (f>. Thoroddsen 

 65°). No. 13. Eyvindarhver, seems to be unchanged, temperature 87°. Oskiirholl 

 (the roaring hill), which seemed in 188S to have become defunct, has now resumed 

 its steam exhalations, accompanied by an ear-splitting din. The steam is ejected 

 with such power, that even in a strong wind, a column of steam rises perpendi- 

 cularly for at least a metre's height (Plate 111). The steam exhalations have perio- 

 dical maxima and minima. The temperature is 91°. Blàhver is unchanged, the 

 surface temperature is the same as in 1888, viz. 82° on the east side of the basin, 

 and 76° on the west. Sample Hveravellir No. 27 is from this spring. Springs 

 Nos. 14 and 15 have about the same temperature now as in 1888, viz. 81" and 64°, 

 as compared to 82° and 67°, respectively; but the exhalations have become much 



