340 Forestry Quarterly. 



it. Several such grubbers are in the market (see notice of Web- 

 ber's grubber on p. 109 of this volume). The praises of Kahler's 

 grubber are sung by Geist, who accentuates that the superior soil 

 preparation is cheaper than older methods which entail repair- 

 planting and loss of increment. 



The cost of plowing furrows with this instrument is $3.60, and 

 at most $4 per acre (10,000 yards. 20 inches wide and deep), to 

 which from 60 cents to $1.50 must be added for harrowing by 

 harrow or hand. But the result in the stand of the sowings is 

 phenomenal, especially in dry humus. 



Two furrow sowings, the one made by the old-fashioned plows, 

 the other by the grubber, succumbed to unusual drouth ; in the first 

 case $10 had to be spent to secure planting plots ; in the latter case 

 no expense for soil preparation was needed. The cost of the im- 

 plement is about $300. 



Zur Kiefernnachzucht, etc., Tiefe Wiihllockerung. Zeitschrift fur Forst- 

 u. Jagdwesen. May, 1900, pp. 333-337. 



MENSURATION, FINANCE, MANAGEMENT. 



It has been asserted by various writers that 

 Value the unit value of work wood — hardwoods 



Increment. in all practical sizes, conifers within certain 



limits — rises in proportion to diameter — 

 (that is, wherever price is an expression of value, as inGermany. 

 Rev.), — so that e. g. for beech, the following arithmetic progres- 

 sion may be found : 



Schubert has investigated this law of the parallelism of price 

 and diameter, expressed by the equation y = ax, i. e., progress in 

 straight lines, for various species on the basis of data from several 

 limited localities. He finds that as a matter of fact, price increase 

 in oak and beech from 8 to 24 inches diameter moves practically in 

 a straight line, with only one exception. With beech, the lines 

 ascend at the ratio of a — \, with oak the appreciation is more 

 rapid, namely at the'ratio of a = 1, or even = i£, i. e., increase of 

 diameter increases value disproportionately. 



Quite different is the relation in spruce and fir. While here too, 



