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qnnrters office at Calcutta, the total would amount to more than a hundred yearly, and these 

 would all have to be tested, named, arranged, and reported upon. 



. Z. Testing of timber. 



The log that furnishes the specimens of wood for a wood-collection, should also furnish 

 the material for the testiug of tlie timber. It is, of course, only intended to obtain a general 

 knowledge of the timber, and therefore the tests cannot be carried out on sueli a large scale 

 as is done in the ordnance and other departments. In testing wood nothing should, however, 

 be left to arbitrary and individual views, but everything should be based as far as possible 

 upon actual experiments, carried on according to a uniform and rational plan, from which 

 alone positive results can be expected, wiiich will not only be valuable to the experimen- 

 ter himself, but also to the general public. The first requirement, therefore, is a strictly 

 uniform system over the whole country by which a clear and satisfactory comparison of the 

 various woods of India could be made. 



It is highly desirable that for testing the breaking weight* and elasticity etc. of wood, a 

 sort of construction should be devised ou which only pieces of wood of exactly the same 

 size and shape, could be used, and which at the same time would be self-working, thus pre- 

 venting abnormalities caused by awkward handling. I think that a four-eornered staff of 

 wood, half a square inch thick by 2 feet long, might be made the normal basis. Five such 

 sticks would be equal to -j'jth of a cubic foot, which would simplify the arithmetical calculations 

 connected with tlie testing of the timber. But should future experiments shew that the thick- 

 ness of the staff is not in proportion to its length, and that it breaks too soon, a staflP 1 inch 

 square might be used, five of which would equal 15th of a cubic foot.f In this case, however, 

 the construction to be used for testing timbers would have to be made stronger in proportion. 



In the annexed sketch I have attempted to give an idea of how such a wood-tester 

 should be constructed, so as to give the most reliable results. I have to introduce two kinds, 

 based upon two different principles : the one might be designated the quadrant wood-tester, 

 and the other the pendant wood-tester. 



1. The quadra)it wood-tenter (fig. I). This wood-tester chiefly consists of a box (A.) of 

 hard wood, into which fits a drawer of utensils (B). C is a board, fastened with hinges to the 

 box, which can be folded up : it serves to bear the counter weights ( W) which will prevent the 

 tester from turning over by the weight ou the opposite side. D is supposed to be a patent- 

 lever, but this might be replaced by a common steel-yard. E represents the wood-expander. 

 F is the projection of the wood-tester itself with the piece of wood on it which is to be experi- 

 mented upon. 



Fig. II. shows the front elevation of the wood-tester, with the arrangement of its difier- 

 ent parts : a is a pole on which the piece of wood is fastened by means of a screw (a (i) ; b 

 is the central pole, on which the priucipal weight of the piece rests, the upper inner part of this 

 pole is rounded off convexedly, in order to allow the piece to move freely and without un- 

 equal pressure ; c is a brass quadrant, fastened to the central pole by means of a brass cross- 

 bar (c c) which strengthens the resistance of the weights employed in the process of testing. 

 This quadrant is hollow and receives into its body a brass solid moveable circle segmentj 

 {d d), of which fig. II. Nos. 1, 2, and 3 give three sections at different heights (No. 1 repre- 

 sents the uppermost end, and shews the manner in which the staff is inserted. No. 2 repi-esents 

 the same after the removal of the cross-bar, which keeps together the outer body of the circle- 

 segment, and No. 3 the upper piece with an indicating needle, J shewing how it fits into the 

 outer body and also the toothed inner ledge from the side). The inner ledge of this circle- 

 segment is toothed, and these teeth play into those of a toothed wheel {d) furnished with a 

 revolving brass or iron handle. 



The manner in which the weights should be applied, is shewn at e. and can easily be 

 understood without a description. The piece to be tested is always supposed to protrude so 

 much from the scaled brass-quadrant that its downward movement is not impeded when it 

 gradually shortens itself by bending under the strain of the weiglits attached to it. 



The flask for the reception of small shot should be of very strong leather, so as to pre- 

 vent its breaking in case of a sudden rupture, and its neck should be very narrow (as indi- 

 cated in the fig. by dots), as it will prevent the contents falling out in case the staff under 

 experiment should break unexpectedly. Instead of the shots and weights, water might be used, 

 but in this case the flask would have to be made of tin and furnished with a clear and pel- 

 lucid stripe of mica with a scale on it, indicating the weight according to the height of the 



* It is worthjf of consideration whether the breaking weight of the sapwood and of the heartwood should 

 be tested. The strength of the heaitwood, liowever, represents the positive strength of the timber, and is of more 

 importance to ascertain for building purposes, than that of the sapwood, which at least, as long as as it is connect- 

 ed with the log itself, exercises possibly but a passive resistance. 



t At the same time I think it would be very useful to have each of the 5 staffs experimented upon, so as to 

 obtain the extremes of the breaking weight. 



;|; This cii'cle segment might also be constructed on the principle of a chain as indicated at e. e. 



