32 
Indian Forest Records. 
[Yol. II. 
4. Apparatus Employed. 
The object of these tests being to obtain comparative figures showing 
the amount of force necessary to split pieces of wood of different kinds, 
an apparatus had to be devised which would effect this result. After 
various trials the apparatus depicted in Plates III and IV was construc- 
ted, the dimensions being as shown. 
The machine, which is made of sissoo wood, consists of a hammer-shaft 
(a) working on an axis [b] in a strong fixed support, and fitted at its 
other extremity with a gun-metal hammer-head (c) . This hammer-head 
is allowed to fall from a given height by its own weight on to a steel 
wedge (<^) of given dimensions ; the wedge acts perpendicularly down- 
wards and splits the block of wood [e) which is held by means of an iron 
clamping-socket (/) vertically below the wedge. The force necessary to 
split any wood specimen is measured by the member of blows required to 
drive the wedge through the wood until the expanded head of the wedge 
[h) comes in contact with the platform (/}. This figure we may term 
the relative splitting force : the fissibility of the wood is the converse 
of this force. 
From the above de.scription it is evident that the relative splitting 
force is an entirely arbitrary one, depending on the size of the wood 
specimen to be split, the weight and dimensions of the wedge, the weight 
of the hammer ami the distance through which it falls. Many prelimi- 
nary trials were made to ascertain the most suitable size of specimen, 
weight of hammer and falling distance, and the following dimensions and 
weights were ultimately adopted : — 
(1) Weight of hammer-head alone, detached . . 9 lbs. 14 oz. 
(2) Weight of hammer-head and shaft (the latter 
not being detached from the axis (4) and the 
scale-pan being placed under the hammer-head 
at a distance of 4^ inches above the platform J) . 11 2 lbs. 
(3) Weight of wedge ..... 2 lbs. 15 ozs. 
(4) Size of wood-specimen ..... Sg" X 1^* ^ la”- 
'i'he remaining dimensions necessary are given in the diagrams, the 
hammer being shown in the position to which it is raised immediately 
before being allowed to fall, an iron pin (y) preventing its being raised 
above the desired height. The hammer is repeatedly raised by hand to 
this position and allowed to fall on the wedge until the wood specimen 
is split through. 
