TRANSACTIONS OF THE SECTIONS. 77 



appearance ; often so extremely fragile, as to crumble on being handled, and occa- 

 sionally forming mere coatings of the most delicate description, on vegetable or 

 bony matter — nay, even upon portions of clothing material, or scraps of writing or 

 printed paper. 



Both of the Strokrs differ from the Geyser in being mere round holes or pipes, 

 neither funnel-shaped at their orifices nor raised above the surface of the ground. 

 They likewise differ from it in the fact that they afford no premonitory symptom of 

 a coming eruption — no previous warning, but all at once dart into the atmosphere 

 with extreme violence. The depth of the Strokr approximates to that of the Great 

 Geyser — being, according to our measurement, 87 i feet, but the diameter of its pipe 

 is rather under 9 feet. 



Shortly after our arrival, the guides cut about a barrowful of turf, which they 

 threw into this Strokr. This at first apparently stopped the violent ebullition which 

 can be seen always going forward in this remarkable spring at the depth of 10 or 

 12 feet, but in the course of ten minutes it began to roar, and then we had an 

 instantaneous and truly magnificent eruption. The water did not appear in a column, 

 as most fountains do, but in a continued intermittent series of many jets all at one 

 moment, having different forces, and unitedly presenting one grand pyramidal jet 

 d'eauofthe most symmetrical and graceful description. Calculating from a little 

 distance in proportion to the figures standing by it, we were satisfied that some of 

 the principal ejections on this occasion — and there were fully thirty of them, lasting 

 in all about ten minutes — must have been from 90 to 100 feet in height, and darkened 

 as the water naturally appeared from the turf thrown into it, the effect was exceed- 

 ingly striking. About twelve hours afterwards we repeated the dose, but the Strokr 

 would not act until it received a double allowance, and then it did so much to 

 the same effect as previously, throwing up stones and portions of the turf to its 

 highest elevation. Three times subsequently during our short stay it erupted spon- 

 taneously, but on none of the occasions was it so fine as when provoked by our 

 feeding it with turf. The Little Strokr is very violent and very noisy. Its eruptions 

 are feathery and extremely beautiful, although it rarely rises above 30 feet, and 

 from the less regular form of its orifice, is not so symmetrical as its larger namesake. 



The action of these hot springs during eruption is not that of a mass of water 

 driven up in column, as the description and drawings of most previous visitors 

 would lead one to expect. The old print pubhshed by Sir John Stanley so far back 

 as 1789 comes nearer to what we witnessed than anything bearing more recent date. 

 Instead of a column, it is rather that of a multitude of jets possessing different in- 

 tensities, all working simultaneously ; so that, whilst a few of them rise perpendicu- 

 larly and attain the highest elevation, others having less power apparently stop short, 

 and others again, being slightly inclined, are thrown out somewhat obliquely — all 

 this, be it remembered, at one and the same moment, the jets intermitting, altering, 

 and repeating their action with the utmost rapidity, and affording to an onlooker, 

 on a quiet day, one of the most sublime and magnificent objects in nature. No 

 doubt the ejection from the orifice of the pipe takes place in a columnar mass. This 

 we distinctly observed it did at the Great Geyser, to the height of 10 to 15 feet above 

 the rim of the cup ; but being accompanied, as these eruptions of boiling water 

 naturally are, by vast volumes of steam, and withal so rapidly changelul in their 

 movements, it is not easy to ascertain exactly what goes on near the orifice at the 

 moment of propulsion. But under no circumstance did this column, as it issued 

 10 feet diameter from the mouth of the pipe, remain long in that form. It surged 

 outwards, and was in.mediately forced up in jets, which, rising abruptly above the 

 volumes of steam, broke in the most graceful feathery masses in every direction. 

 Stones thrown in, and particularly the masses of turf with which we supplied the 

 Strokr, were driven out to the highest extremity of these jets, some of them falling 

 outwards, and others dropping into the vortex, and being a second or a third time 

 driven into the atmosphere. How all this takes place — the structure of the ma- 

 chinery which causes such magnificent action — or, in fact, what goes on underground, 

 it is not my province to speculate upon. 



I close these remarks by noticing a few of the recent changes which are observable 

 in this locality. Sir John Stanley in 1789 found the pipe of the Geyser 61 feet deep, 

 and 8^ in diameter. The funnel, or basin, as he terms it, is stated at that period to 

 have been 8 feet in depth and 60 feet in diameter. "Both of these," he says, "have 



