Part II.] Troup: Fissihility of some Indian Woods. 
35 
force acts. Radial as compared 
with taagenfial cleavage. 
great difficulty or refused to l)e cut through at all, the wood being ulti- 
mately split only after repeated blows which gradually tore out the 
fibres in the form of rough .splinters. In such cases the primary cause 
of difficulty in splitting, however, was the crossness of the grain rather 
than the hardness of the wood. 
Text-books teU us that wood splits more easily in a radial than in a 
tangential direction. This may possibly hold 
(c) Dir<:ctIon la^ which the^ with most European woods, but the reverse is 
certainly the case as far as the great majority 
of Indian woods are concerned, judging from 
the results of the tests described in this Article, for of the 61 woods 
tested the splitting was easier along the tangential plane in 43 woods, 
and easier along the radial jdaue in 11 woods, while in the remaining 7 
woods the splitting force was identical in each plane. The results 
tabulated in the Appendix show that of the 11 woods where fissihility is 
greater in the radial direction, in every case the difference between the 
radial and tangential splitting force is less than 2 units, while of these as 
many as 9 woods show a difference of only one unit or less. Thus in no 
case is radial splitting markedly more easy than tangential splitting. 
On the other hand this difference amounts to over 10 units in nine different 
woods where the splitting force is greater in the radial than in the 
tangential direction, the difference being as much as 87 '29 units for 
Ougeinia dalhergioides, ‘62)‘o units ioi Dalbergia Oliveri, 21 units for 
Falbergia latifulia, 20 units for Banhinia reUna. and 19'33 units for 
Pterocarpus Marsupium. In the case of Dalbergia Oliveri, splitting in 
a radial direction is more than 17 times as difficult as it is in a tangential 
direction ; in Ougeinia dalbergioides it is more than 13 times, in Pterocar- 
pm Marsupium more than 12 times, in Shorea robust a more than 9 times 
and in Dalbergia latifolia 7 times, while in many other woods the diffi- 
culty of splitting radially as compared with tangentially is much more 
marked than in any of the woods where radial fission is the easier. 
Finally, if we take the average splitting force for all the 61 woods, 
we find it to be 7‘79 for radial and 2'92 for tangential splitting in the 
case of dry wood. As the woods tested may be taken to be fairly 
representative, the results prove beyond doubt that, as far as Indian 
species are concerned, wood as a general rule splits a good deal more easily 
along a tangential than along a radial plancj. It has already been 
mentioned that cross-grain is encountered during radial and not during 
