The Conversion and Characteristics of Colony Timber. 297 



saws. However, if the cost of new teeth for cutting a given quantity of 

 timber be reckoned against the work done by a new solid tooth saw 

 before it is discarded, figures would be found in favour of the latter. The 

 class known as the solid plate tooth, with an average hook on the teeth 

 and just enough to get a good grip of the wood, should be used as a 

 matter of choice when a circular is required. 



The Log Band Saw. 



This saw is undoubtedly a fine invention and highly suitable for the 

 soft North American timbers. The question whether the vertical or 

 horizontal log band saw is the more useful and quicker is still, however, 

 a subject of controversy. I believe there are four of this type of saw in 

 the colony, of which only one is constantly at work. It is, however, to 

 my way of thinking, unsuited for sawing our timbers. In our hardwoods, 

 which are generally required in long lengths, the saw does not and 

 cannot work effectively at the required high speed, especially as the bulk 

 of our timber is cut green. Running for a greater length than 16ft. with 

 the high tension necessary for cutting hardwood, the great friction is 

 prolonged and coupled with vibration of the band crystallization is set 

 up. The crabwood logs at present procured for conversion are very small, 

 from 8" x 8" to 20" x 20", this latter size but seldom, so the necessary 

 power to run the saw is practically wasted on such small sizes, whereas 

 with very little more power a 30" log could be put through and at the 

 end of the day a fair footage would be shown as sawn. Even with crab- 

 wood I have seeu the sawyer cooling oft' the saw with water on account 

 of the high friction set up. A trifle more set on the teeth may overcome 

 the friction trouble, but such horrid hard knots are frequently met with 

 when breaking down greenheart timber that there is great liability of 

 snapping your band if the kerf is increased. Fortunately, the mill I am 

 now running has no log band saw, and I should not recommend it under 

 present conditions. 



The Log Frame Saw. 



Up to the present time the log frame saw has proved itself the 

 most effective for conversion of the timbers of British Guiana, and, like 

 most things, it has both its good and bad points, but with proper handling 

 from four hundred and fifty to five hundred and fifty lineal feet of logs 

 can be sawn in a working day of 9£ hours. 



The overhead direct driven vertical log frame saw is highly suited 

 for the manufacture of boards, planks and scantlings from our hardwoods 

 and gives no trouble whatever during operation. One requires, however, 

 to be very careful about the gauges of frame saws or webs, as they are 

 technically termed, also set of teeth for soft, hard and gummy timbers, 

 and more particularly that the correct hook on teeth and sufficient gullet 

 are provided to permit the dust to recede and thus entirely free the point 

 of tooth for cutting on the downward stroke. 



Operating Costs. 



It might have been interesting to have given details of operating- 

 costs but for obvious reasons this is not advisable. 



