1920] CURRENT LITERATURE 



1 59 



as rosewood, some as black as ebony, while others have a lighter color. Species 

 of Casuarina also yield hard wood of various colors, some looking like oak 

 already fumed. 



The hardness and weight of Eucalyptus timbers are due to the predomi- 

 nance of thick-walled fibers. In some of the extremely hard woods of the 

 genus the vessels are almost entirely blocked by tyloses. The figure in the 

 wood is not due to large rays, as in oaks, but to the fact that fibers and wood 

 elements run in waves. In color, this single genus furnishes perfect imitations 

 of maple, locust, cherry, mahogany, and rosewood; while the timber, as 

 hard and strong as any of these, takes a magnificent polish. 



The taxonomic sequence follows that of Bentham and Hooker. In each 

 case there is a systematic diagnosis, with geographical range, and a descrip- 

 tion of the timber and its uses. Local names are given in addition to the 

 scientific names. The rank in a scale of hardness and the weight per cubic 

 foot are also given, and some of this information is summed up in a table 

 according to hardness: extremely hard, very hard, hard, and moderate. In 

 most cases photomicrographs illustrate transverse, longitudinal radial, and 

 longitudinal tangential sections, which not only show the structure but also 

 indicate the strength, hardness, and weight of the wood. 



An unusual feature is a table of combustibility. Since wood in Australia 

 is used to a considerable extent in railroad bridges and in shipbuilding, resist- 

 ance to fire is a very desirable quality. By means of a "xylopyre" the time 

 required to burn up a piece of wood of a definite size was determined with 

 great accuracy. These tests show that many of the Australian woods are 

 remarkably resistant to fire. In this quality Eucalyptus Fletcher i easily 

 heads the list, with 19 minutes required to burn the test piece; next comes 

 Syncarpia laurifolia, with 12 minutes; then Casuarina torulosa, with 8 minutes; 

 followed by many species of Eucalyptus ranging from 7 minutes down to 

 3 minutes. The significance is evident when we note that in the same test 

 our Pseudotsuga Douglasii has a time limit of 4 minutes, Quercus alba 3 minutes, 

 Juglans sp., Fagus sylvatica, and Sequoia sempervirens less than 3 minutes. 



A striking feature of the work, and one most likely to give it immediate 

 practical importance, is a series of 126 magnificent plates in color, illustrating 

 the natural appearance of the wood. These plates, together with the photo- 

 graphs of various articles, inside furnishings, buildings, etc., prove the variety 

 and value of the Australian hardwoods. 



The timely warnings, calling attention to the desirability of sane lumbering 

 methods and the necessity for reforestation, should be heeded while the timber 

 supply is still abundant.— C. J. Chamberlain. 



NOTES FOR STUDENTS 



Form and growth of trees, — In 1913 the Schnyder von Wartensee Foun- 

 dation opened a prize competition of three years' duration "to stimulate 

 new investigations upon the growth in thickness of trees." First prizes 



