Periodical Literature. 495 



MENSURATION, FINANCE AND MANAGEMENT. 



According to Forstamtsassessor Wild, of 

 New Lindenhardt (Ober Franken) the existing 



Self-recording self-recording calipers have not found 

 Caliper. entrance into general use because they are 



too complicated and hence get easily out of 

 order. The reason for their complication 

 he finds in the fact that they have counting register, which re- 

 quire not only a large number of wheels but as many springs, so 

 that for a caliper with 30 diameter graduations 90 wheels and 90 

 springs are required, if constructed for one species only, and 

 three times as many for three species. The inventor overcomes 

 the difficulty by substituting for the counting apparatus an ar- 

 rangement in which small steel balls, for different species of 

 different size, register the number of trees of different diameter 

 and can be sorted afterwards by size (species) and counted. 



To do this the moveable arm at its base has attached receptacles 

 for the balls, as many as species to be measured, each recep- 

 tacle being provided with a press button to release balls and let 

 them fall into another receptacle which is divided into as many 

 compartments as their diameter graduations, the proper com- 

 partment being automatically presented for the ball to fall into. 

 To sort the balls sieves of different size are used, and to count 

 them they are measured by 25s in cartridge-like boxes, which 

 operations require a few minutes only. The ball supply recep- 

 tacles must, of course, be marked for the species they represent; 

 the smallest caliber for the most frequent species, and, of course, 

 for use with a single species only one supply receptacle is needed. 

 The weight when loaded is less than four pounds ; the construc- 

 tion is sim.ple, and the instrument works in any kind of weather. 



So far the instrument is not 3^et manufactured generally, in- 

 deed, not yet patented. The inventor invites correspondence as 

 regards furnishing instruments. 



Bine Sclhstregistrirekluppe fiir meltrere Holsarten. Forstwissenschaft- 

 liches Centralblatt. June, 191 1, pp. 305-308. 



