Miscellaneous Intelligence. 44] 
3. Charcoal having the solidity and texture of mineral coal fo 
under pressure.—We have received from Mr. Robert Safely, of Cohoes, 
- Y., an account of the conversion of a portion of the wooden ste 
a ee iu Tad Sass oP eet bee i 
texture and appearance ordinary mineral coal, along with a specimen of 
the coal. The step was of oak, and about 10 inches through ; and when 
ing clogged with dirt. Mr. Safely states further that the fall of water 
to which the wood was subjected when it was converted into coal, was 
exactly 25 feet; and as the diameter of the wheel is 5 feet 7 inches, the 
pressure on the wheel would be measured by a column 5 ft. 7 in. in di- 
. ameter and 25 ft. high, less what is due to the water striking the bucket 
P at a small angle to the plane of the wheel. The gearing, wheel, shaft, 
: ete. weigh about 3 tons, which would give for the pressure upon the step, 
if the whole weight of the water was reckoned, about 20 ton 
4. On the field of Vision in Man; by F. Foucovu.—Mr. Foucou gives 
the following results of his measurements of the amplitude of the field 
‘ of vision in the case of two persons, Mr. Leboucher and Mr. Puchot 
Mr. Lesoucuer. Mr, Pucuor. 
i Right eye. Left eye. Righteye. Left we 
: Superior limit of the field, 68° 12! 63° 14% F 5 
° 
3 Inferior limit “ fc oe 74° 41’ 16° 46’ 44° 
3 Internal limit « 60° 5/ 67° 25’ 59° 54’ 64° 
External limit “ 101° 23° 97° 03’ 107° 52/ 99° 
Horizontal diameter of field, 138° 9/ 137° 55’ 129° 34” 128° 
Vertical - 161°28’ 164° 287 167° 46’ 163° 
The following conclusions are stated : 
That in the same individuals, the field of vision has approximately 
the same breadth in the two eyes along the same diameter, while the 
: horizontal and vertical diameters in the same eye differ widely. 
That in both eyes, in the case of both persons examined, the angle for 
. the outer limit of visibility is greater than a right angle, so that a ray of 
: light making an obtuse angle with the axis of the eye can nevertheless 
duce an image on the retina. 
That the angular limits of vision are not the same in different persons ; 
this difference for the superior limit of visibility amounts to 10° at least, 
but is almost nothing for the inferior limit; for the outer limit it may be 
6°; for the inner but slight. 
Au. Jour. Scr.—Secoxp Sens, Vou. XXXVIII, No. 114—Nov., 1864. 
