Cut Wood Research Articles

The Hillsborough, New Brunswick, mastodon and comments on other Pleistocene mastodon fossils from Nova Scotia

This is the first detailed description of the remains of a young adult American mastodon (Mammut americanum) found in 1936 in peaty silt and clay underlying till in gypsum karst near Hillsborough, New Brunswick. It documents 312 fossils comprising a partial skull with molar teeth and tusks, a neck vertebra, and much of the right postcranial skeleton. An individual age of 15 – 18 years and a weight of 8.3 t are estimated for this mastodon. Associated spheroids, containing cut wood fragments and an unusually high clay content, are interpreted to be mastodon coprolites. Radiocarbon ages are 13 600 ± 200 (bone), 37 200 ± 1 310 (coprolite wood), 51 500 ± 1 270 (coprolite carbonate cement), and >43 000 BP (peat). Pollen in the coprolites and associated sediment indicates a coniferous forest. Nine other mastodon fossils from Nova Scotia include a femur from Middle River, which dates 31 300 ± 500 BP and contains pollen representing boreal forest – tundra, and three molars from offshore Georges Bank. All ages are judged minimal: the older four are at or near the limit of the method; the younger is likely incorrect because of preservative contamination. Associated pollen assemblages correlate with late last interglacial age deposits in the region and differ from possible Middle Wisconsinan age deposits. The fossils are regarded as a single group and are assigned to a cool phase of the Sangamonian interglaciation, probably oxygen-isotope substage 5a, prior to Wisconsinan glaciation.

Physical workload, perceived exertion, and output of cut wood as related to age in motor-manual cutting.

Physical workload, output of cut wood, and perceived exertion were studied among 15 younger (mean age 29 years) and 16 older (mean age 59 years) lumberjacks, using a chainsaw and paid on a piece-rate basis. Oxygen consumption was measured with portable equipment, while heart rate was measured telemetrically. The oxygen consumption for all working phases was 1.8 +/- 0.2 l/min (means +/- SD) (younger) and 1.5 +/- 0.2 l/min (older), which corresponded to 49 +/- 4% and 53 +/- 7% of maximal oxygen consumption estimated in ergometer bicycle exercise test. A negative relationship was found between relative oxygen consumption at work and maximal oxygen consumption (ml/kg/min). Mean heart rates for all working phases were 138 +/- 10 beats/min (younger) and 126 +/- 17 (older). The heart rate differed between the working phases, and was significantly higher for both groups during bunching than during the other operations. The output of cut wood did not differ significantly between the groups. Slight but significantly relationships were found between output of cut wood and maximal oxygen consumption (ml/kg/min) and oxygen consumption (ml/kg/min) during work. Rating of perceived exertion (RPE) and simultaneous heart rate recordings during cycle tests and field studies showed significant correlations between heart rate and RPE values during cycling in both groups. RPE values and heart rate in the field showed a slight correlation (younger) and not at all (older).

Extractive forest resources of the Tana River national primate reserve, Kenya

Plant uses by the Pokomo and their influence on riverine forest structure and composition are examined in the Tana River National Primate Reserve, Kenya. Of a total 98 plant species identified with one or more uses, 15 are used as food, 34 for construction material, 43 for technology, 23 for remedy, 2 for commerce, and 20 for other uses. The mean basal area of cut wood is 3.21 m2/ha, mostly from palms (1.96 m2/ha) and understory trees (1.20 m2/ha). Measured impacts on forest structure include the loss of large trees for canoes or beehives, lowered palm heights, and tree coppicing. Accessibility explains much of the spatial pattern of use. Extraction activities do not reduce forest area, and causal effects on productivity are complicated by the heterogeneous environment and past disturbances. In view of regional pressures on forests and cultural traditions, limited resource extraction offers incentives for local stewardship of a unique ecosystem.

Some Aspects of Mealybug Behaviour in Relation to the Efficiency of Measures for the Control of Virus Diseases of Cacao in the Gold Coast

Mealybug populations (Pseudococcus njalensis Laing) originally present in piles of slash infected with the virus of swollen shoot of cacao are usually small. It is suggested that many of the insects leave the trees at an early stage in the development of infection.Slash piles offer conditions which induce mealybugs to remain within them. The piling of infected slash retards the rate of wilting of the cut wood and consequently retards the rate of migration of the mealybug population. The construction of piles protects the mealybugs from direct insolation and rainfall and leads to the persistence of the population on the cut wood. The colonies which survive the longest are those in the lower part of the heaps where death and desiccation of the material is most delayed.Mealybugs continue to live and to reproduce within heaps of slash for as long as nine weeks or more. Reproduction of the mealybugs is stimulated as the tissues of the felled trees become wilted and the resulting first-instar nymphs contribute numerous participants to such migration as does occur. There is evidence from laboratory experiments that these insects are not potential vectors.The concentrating of mealybugs in slash piles produces no increase in the population of Coccinellid or Cecidomyiid larvae within the piles.Mealybugs are capable of walking quite rapidly for long distances over smooth surfaces. They become incapable of movement when starved for a few days and the majority die within a week. A soil surface seriously impedes the progress of mealybugs which leave the slash heaps and this effect is more marked with the nymphal stages. Even on clean-weeded soil the rate of travel is slow and few. if any, insects can travel over appreciable distances in the period during which the virus may persist within them. Results of preliminary experiments were confirmed by the use of insects labelled with radioactive phosphorus.Some of the ants, which become associated with slash piles and which remain in attendance of the residual mealybug population, carry mealybugs, but the number of insects transported in this way is of little practical significance.The establishment of migrating mealybugs on seedlings and mature cacao is poor even in the presence of their attendant ants.All these factors make the possibility of infecting healthy trees from infected slash extremely remote. There is accordingly no reason to believe that the efficiency of “ cutting out ” is seriously reduced by the movement of vectors from the infected trees which are cut out.Without the co-operation of farmers in supporting the removal of contact trees no further recommendations can be advanced to improve the present method of control of swollen shoot.

Some Observations on Raised Grain

Abstract Woodworkers and finishers are confronted with certain difficulties classed under the category of “raised grain” which, so far, have resisted satisfactory solution. This paper describes some observations on raised grain that may lead to a better understanding of the problems and which may suggest approaches toward overcoming them. Casual investigations made of raised grain suggest some remedial measures, and indicate that there is a large field for research connected with the surfacing of lumber, both as to the cause of the objectionable features encountered and methods of overcoming them. A microscopical study of the way that present-day woodworking tools and machinery cut wood and the development of new equipment which would give more nearly ideal results seem to offer possibilities which would go a long way in improving wood products or reducing their costs.

Curved Knives

IT may interest your correspondent, Dr. Otis T. Mason, to know that the curved “drawing-knife” described by him has representatives in Western (British) India. The Kolis (fishing races) of the Bombay coast wore lately, and some still wear, knives made by local blacksmiths, of which the blade, 2 to 3 inches long, was shaped and edged like that of an English gardener's knife. There was no hilt, but a tang curved reversely to the blade, ending in a little curl. The whole figure was that of a manuscript capital S, with the lower curve heavily drawn and a fine finish at the top. Through the curl was passed a soft lanyard, and the whole worn round the neck, the knife hanging like a locket a little below the collar-bone. The way in which a man, holding the thin tang between the thumb and forefinger, or between two finger-knuckles, would cut anything, from a cable to a fish's head, was the more wonderful, as he would often prefer bringing his breast near the object to unslinging his knife. These knives are now passing out of use, displaced by old English and German clasp-knife blades, still without the hilts. The form must be very ancient, as bronze knives or razors of much the same shape are figured in most books about the European Bronze Age, and in Du Chaillu's “Viking Age.” I am inclined to suspect a flint origin for this form of tool. Flint flakes in Western India, from Sind to the Konkan, often show a curved inner edge with traces of use. And if any one tries to cut wood with a hiltless flake of the sort, he will find the inner edge the most efficient. The Indian farrier's “drawing-knife” is shaped like a sickle, squarely truncated to avoid the chance of injuring the horse's foot (just as the English farrier's knife is turned to one side for the same reason). Its hilt is a mere roll of coarse tape, but the grip of the hand is often that shown in Dr. Otis Mason's illustration.