760 KANSAS CITY REVIEW OF SCIENCE. 
the one the farthest west will first experience an east wind on the approach of a 
storm-area, 
" A good hearing day is a sign of wet ; 
Much sound in the air is a sign of rain." 
Why ? Is it not because in a rainy time, the air moves in different currents 
with different densities, on account of which the vibrations are not readily trans- 
mitted upward, but are confined to the lower stratum of air ? The lower stratum 
would not be altogether unlike a drain-tile tube through which a mere whisper 
can be heard fifty yards. I would not consider Tyndall's theory that audibility 
was due to the homogeneity of the atmosphere, but to the reverse, unless we 
are to understand the word horizontal before homogeneity. 
The sound of thunder and of the firing of heavy cannon is not conveyed so 
much through the atmosphere as through the very crust of the earth, and hence 
the proverb applies less to sounds of this character, than to others of less inten- 
sity. 
In Mr. Scott's discussion of the above named paper, he said that no one 
had as yet been able to forecast the amount of rain that would fall at a given 
place on a given day, and that inability to do so was apparently owing to ignor- 
ance of the conditions of the upper atmosphere. Now it must be conceded that 
for any area, say for 500 square miles, having equal length and breadth, in a 
level country like northern lUinois, the conditions of the upper air must be uni- 
form in clear weather, and yet a storm may occur in one portion of such an area, 
and rain fall to a depth of two or three inches, while other parts are for the time 
rainless. Hence it would seem that our abiUty to foretell the amount of daily 
rainfall would not be enhanced by knowing the conditions of the upper air. 
Mr. Abercromby states that the ice-film which forms the cloud in which the 
halo is formed is only produced in front o{ cyclones or thunder-storms, and for 
that reason is a sign of rain. The fact is, the halo is formed whenever the rays 
of the sun or moon are intercepted by the ice-film and may be de/ore the storm- 
cloud, after it, or a thousand miles from it. Almost any of the cirri or cirro- 
strati will exhibit the halo, its brightness depending upon the number form, ar- 
rangement and movement of the frost-crystals composing the cloud. 
" Anvil clouds are very likely to be followed by a gale of wind." Now 
what are meant by " anvil clouds" ? I am sure I do not know. There are 
frequently seen in summer along the horizon, clouds the shape of which very 
perfectly represents the form of an anvil, and these are probably referred to. 
These clouds are small thunder-showers from fifty to one hundred and fifty miles 
distant and deserve especial study. One may learn by watching these clouds 
how the "horn" of the anvil always points forward, and how lifter dark the 
lightning will gild, not this part, but the rear and sides of the cloud, and also, 
by assuming the distance, we may tell the velocity of the storm. When one sees 
a cloud of this type he may know of a certainly that the storm, or more properly 
shower, will not pass over his locality, since it takes the direction that the anvil 
