385
face of the ground, and, where there is much water, the dimensions are increasedto 1' 6" x 1' 4".
“ For the smaller drains, excavations are made 2and 10 inches to 1 foot wide; at the bottom ofthem stones are placed with the edges leaning againsteach other, so as to form an arched way for thewater to run through, and they are filled in, towithin about 1 foot from the surface, with loosestones, broken to about 3 inches cube.
“ These drains are placed in ordinary ground about18 feet apart, but in very wet ground not more than15 feet, sufficient fall being given to prevent the water from lodging in them; theyare led into the main drains as shewn below.
4 ft. to an inch.
Fig. 8.—Section through a b, fig. 9.
Fig. 9.
SMALLER
CRAINS
Scale 50 feet to an inch.
“ The expense and mode of operation will of course vary according to the descrip-tion of country, the system shewn above being adopted in ground where there is asupply of stone raised in the excavations which is nearly sufficient for filling in thedrains.” R. J. N.
E.
ELECTRICITY—as in various degrees called into existence on any change inthe mechanical or chemical construction of bodies: and the object of all electricapparatus (other than those for scientific investigation) is to obtain control over itsdirection when developed by natural causes, or over its action when producedartificially.