948 A FESTIVAL OF GNATS. 
On watching one of the columns closely, it was apparent that all the 
gnats had their heads one way, facing the breeze, which, however, was a 
very light one. It was a calm evening; what air-current there was came 
from the south-east. It seemed to be sufficient occasionally to press 
back the column a few inches from its normal position, and whenever 
this happened the whole body of gnats jerked themselves forward again 
with one perfectly synchronous impulse. How this was accomplished it 
is difficult to understand. But in fact their whole manceuvres were 
mysterious, and suggested a variety of questions. 
What do these little creatures do during the day, and what do 
they feed upon ? 
What was the object of their evening exercises? They were in 
constant motion, but seemed never to jostle one another. 
Why on that particular night did they arrange themselves in vertical 
columns, with such a general uniformity of shape and size? 
How, in their rapid and perpetual motion, were they able to 
maintain their formation with such precision that at a short distance 
the columns seemed quite stationary ? 
How did they contrive to keep such perfect time in their sudden 
leaps against the wind ? 
Many of the phenomena of insect life seem to suggest that these 
little animals have some sense—perhaps several senses—quite unknown 
to us vertebrates. May there not be other “gateways of knowledge” 
besides the five by which it enters our fortified brains? Why not an 
electric sense, which should vibrate to electric currents, as the ear to 
sound or the eye to light? 
AN EXCURSION TO FROGHALL, CALDON LOW, 
AND ALTON.* 
BY JAMES SHIPMAN. 
It was seven o’clock in the morning of the 5th of last October, and 
a somewhat cheerless grey mist hung low overhead, as a small party of 
the Natural Science Section of the Nottingham Literary and Philo- 
sophical Society steamed out of the Midland Station on a visit to the 
famous ironworks at Froghall, the limestone quarries at Caldon Low, 
and to lovely Alton—the last geological excursion of the season. Anyone 
but the most astute meteorologist, and one conversant with the sudden 
atmospherical changes of the last two years, would have predicted 
something more substantial than mist. As it was, however, we were 
all destined to be agreeably surprised by the bright day that was in store 
for us. The charmingly picturesque valley of the Churnet about Alton, 
up which we glided as we approached our destination, was not seen to 
much advantage under the circumstances. But there was still the steep 
* Read before the Natural Science Section of the Nottingham Literary and 
Philosophical Society, Dec. 20th, 1878. 
