48 Correspondence. [January, 
the height of the second-floor windows. A cat which was walking 
in the garden made a sudden leap upwards, as if in the hope of 
seizing them, though her spring did not of course carry her one- 
tenth part of the height that would have been requisite. 
We generally suppose that every animal has a practical know- 
ledge of the extent of its own powers, without which, indeed, it 
would fare badly either in capturing prey or avoiding its enemies. 
Moreover, we feel warranted in concluding that it knows the 
powers of its enemies. Thus both cats and birds know that 
dogs cannot climb, and when in a tree exhibit perfeift unconcern. 
But the cat in question, though of mature age, seemed as little 
able to judge of distance as is an infant when it grasps at the 
moon. 
The only other conceivable interpretation of the leap is that 
Puss was excited out of her sober judgment at the mere sight of 
sparrows. 
Another case of apparent feline stupidity may often be ob- 
served : — If a canary, or other small bird, is set in its cage near 
a window, a cat will often post herself on the ledge outside and 
stare for an hour, if not driven away, frightening the bird almost 
to death. Now surely every cat must have learnt, from its own 
individual experience, that glass if pervious to light is not so to 
cats. 
It seems to me that the great difficulty we encounter in studying 
the intelligence of animals is their extreme inconsistency, or, I 
might perhaps better say, the mixture of rationality and irration- 
ality which they exhibit. — I am, &c., 
H. S. 
[Perhaps to higher beings human condudt might exhibit the 
same medley of wisdom and folly which we think we find in the 
lower animals. — E d. J. S.] 
EARTHQUAKES AND ELECTRICITY. 
To the Editor of the Journal of Science. 
Sir, — I would take this opportunity of referring to an article in 
your December issue on “ Earthquakes,” &c. In this it is stated 
— “ It is now well established that in India, at all events, earth- 
quakes are almost always accompanied by furious storms of 
thunder,” &c. Now I have had personal experience of three 
earthquakes, my wife of one, and my sister (now with me) of 
two, all independently of the others. Neither thunder, lightning, 
