NATURAL HISTORY NOTES. 
25 
Safety Stage for the Microscope.— At the meeting of the Royal 
Microscopical Society on November 14th, Mr. Stewart exhibited a 
safety stage which he had invented, chiefly to meet the want which 
is sometimes felt in exhibiting a perhaps valuable slide to a class 
of students, or other inexperienced persons, who are very apt to 
break the cover-glass by racking the objective down upon it. A piece 
of wood rather wider than an ordinary glass slide has a hole cut in the 
centre large enough to admit the light to the object. Between this 
hole and the sides of the piece of wood two small strips of wood are 
fixed, and on the top of each of these is a thin strip of brass, rather 
longer than the strip of wood, so as to overhang at each end. A 
couple of india-rubber rings are then passed, one round each pair of 
projecting ends, and between these, suspended in a kind of hammock, 
is placed the slide which it is desired to protect. If then the ob¬ 
jective is brought down upon the cover-glass, the india-rubber springs 
yield to the pressure, and the object is saved from destruction. 
Ice-grooved Boulders.— The curious phenomenon of ice-grooves 
passing round the corners of boulders, mentioned by Mr. W. J. 
Harrison in the December number of the “ Midland Naturalist,” as 
having been observed in the basalt boulders of the Rowley Hills by 
Dr. Crosskey, reminded me of something similar that came under my 
own notice while rambling on the south coast of the Isle of Man 
during a holiday visit in the summer of 1875. It was just south of 
Port St. Mary, where the extremity of a blunted spur of coast is 
fringed for about half-a-mile with Lower Carboniferous Limestone. 
At one spot the sea was quietly removing the stiff brown boulder clay 
that hid the limestone in some places from view. A miniature 
promontory of limestone, two or three feet in length, that had 
recently been uncovered by the waves, attracted my attention on 
account of some ice-scratches that I thought I could detect on it. 
The little projecting rock rose into a peak or crest down the middle, 
and the ice-scratches and grooves passed right over the smoothed and 
polished ridge from one side to the other, or in an east and westerly 
direction, and parallel with the coast-line, instead of away from it, as 
one would have expected. How to account for these scratches by the 
action of floating ice was long a problem to me, for I had not yet 
learnt that most of these striations on rocks had been produced by the 
action of land-ice or glaciers. Of course if this rib of polished and 
scratched limestone came to be torn up and broken into boulders by 
the action of the waves, some of these boulders would present the 
curious phenomenon noticed by Dr. Crosskey of striae passing un¬ 
interruptedly across the corners from one face to another. I am glad 
Mr. Harrison was so thoughtful as to mention the matter in the 
pages of the “Midland Naturalist,” as otherwise I should have 
heard nothing about it. It seems to me rather a misfortune that 
such papers are not either distributed more widely among the Societies 
in the Union or reprinted in this magazine. Such papers as 
Dr. Crosskey’s are of absorbing interest to most geologists.— 
J. Shipman, Nottingham. 
