2 Rey. William Scoresby on the 
within the surface of the ground, so as, except incidentally, 
to be hidden from observation. There they form a thin stra- 
tum, or sort of platform, of clusters, prisms, or needles, ver- 
tically arranged, which, springing out of the earth beneath, 
adventitiously push upwards on their summits a pellicle of 
the earth, or gravelly surface of the ground. 
Instead of attempting to generalize the phenomena, how- 
ever, which the limited nature of my observations would 
scarcely justify, it may be safer, for the sake of accuracy, 
rather to give the results of what I observed on the particu- 
lar case referred to. 
It was in the morning of the 6th of October, of the present 
year 1849, after a clear, frosty night,—leaving the ground 
thickly covered with hoar-frost, and the general surface hard 
frozen,—when my attention was directed to an unusual dis- 
turbance of some parts of the surface of a gravel-walk, on 
which I was in the habit of taking exercise. Ofttimes, in- 
deed, I had noticed the loosening of the surface of gravel- 
walks, or gravel-covered roads, by the operation of a night’s 
frost; but I had never observed the disintegration so com- 
plete, or the general surface so crisply spungy as on this oc- 
easion. The first portion examined was on a wide terrace- 
like walk, covered with fine gravel mixed with earth, which 
did not usually bind with much compactness. Being ‘ex- 
tremely pervious to water, and heavy rains having recently 
prevailed, the walk, though pleasant enough for exercise, 
contained a large quantity of moisture, and more parti- 
cularly on the side next the grass descending into the lawn, 
which was little trod upon. 
Here I observed the surface of the gravel to be raised an 
inch or two above the proper level, appearing rough, and the 
elements of which it was composed disjoined ; in some places 
the appearance was cauliflower-like ; in others more evenly 
rough, but separated by parallel curvilinear striz into corre- 
sponding ridges. Occasionally, where the gravel had not been 
raised, there were little patches of exposed ice-crystals, from 
an inch to an inch-and-a-half high, all standing, closely as- 
sociated but separate, in prisms of clustered needles, perpen- 
dicularly to the general surface of the ground. On examin- 
