202 EXAMINATION OF DRIFT. 
ee 
on the face at which the men are at work, and when last visited the 
beds occurred in the following order :— 
Top soil and gravel.. ate Sh ae -. 9 feet. 
Red sand, with thin seams of drift coal. se oi -» 18 inches, 
Band drift coal ee ne as a4 55 6G oi VLE Bae 
Greysand .. ee ee ze ee oe A. TA 
Gravel .. é 46 As Ac =- Ae oct Julies 
Coarse sand .. ae no ae 50 oa as & Gee 
Gravel, with drift coal aa ae on a ae aie. Eee 
Sand .. ae aie oe a aie os oon Lae 
Band drift coal . aia of si 54 GA a ° 30 bam 
Fine dard a4 A as ne os. baie 
Gravel, with drift coal in large pieces ac 3 54 337 18 
The beds of sand in this section thin dat into the pelts of gravel 
towards the south, so that the latter beds are some inches thicker on the 
north side than on the south side of the cutting. 
The whole locality abounds in pebbles of igneous rocks, but by far 
the most abundant are those of quartzite, and many of these are from 
6in. to 8in. diameter. Striated pebbles have not yet been found, nor do 
the boulders examined appear to have any striations; the underlying 
formations are the coal measures, and coal crops out in the immediate 
neighbourhood. The nearest localities for basalt are Pouk Hill (one and 
a half miles due north), and Rowley Hill (five miles south); and for 
quartzite, the Lickey Hills (twelve miles south). 
These cuttings cannot fail to give instructive information to anyone 
making a careful examination, and this should be done at once by who- 
ever desires to do so, as the line is being rapidly proceeded with, and the 
sides are smoothed down and the boulders cleared away as the work goes 
on, so that the aspect of the deposit is rapidly changed. Anyone, there- 
fore, who is interested in the subject, and has opportunity to visit the 
spot frequently, would be enabled to report upon it more completely and 
to greater advantage; and I commend this locality, as one well worth 
reporting upon, to those who may be examining the drift deposits of the 
district. 
THE AUDIOMETER. 
BY WRIGHT WILSON, F.L.S., HON. SURGEON TO THE BIRMINGHAM AND 
MIDLAND COUNTIES EAR AND THROAT INFIRMARY, ETC. 
Recently I had the pleasure of introducing this instrument to the 
notice of the Birmingham and Midland Institute Scientific Society. It 
is the latest outcome of those wonderful inventions—the telephone and 
microphone. The apparatus was contrived by Professor Hughes in the 
course of experiments made by him in electric induction, as recently 
described by him to the Royal Society. It consists of a battery, a micro- 
phone, two primary coils, a secondary coil, and a telephone. The 
secondary coil is movable on a boxwood bar ; at one end is fixed the large 
primary coil, which contains 100 metres of insulated wire; at the other 
end is the small primary coil, having only six metres of wire. The 
secondary or induction coil has 100 metres of wire. The horizontal bar 
on which it slides is graduated into 200 parts; this is the reading scale 
