518 FOOTE— FACTORS IN THE [April 25, 



accountably reduced, some of the shortage is considered in the ex- 

 change vahie given to such falls. 



2. The Group Weight. — A modification of the admittedly im- 

 perfect Rose-Tschermak-Brezina group classification, is used, show- 

 ing each group weight. 



3. The Number of Owners. — Wiilfing acknowledges the unre- 

 liability of this factor, in that some owners have not enough to part 

 with any and should therefore not be included. However he in- 

 cludes all owners as of equal importance in his formula for finding 

 the value of a fall, arguing that when divided among many holders, 

 it is less desirable in other eyes. 



The following variable factors, which he excludes, are then re- 

 ferred to as not being computable or as of insufiicient weight to be 

 utilized in working out the formula: (4) Material which may be 

 found in the future and thus raise certain group-weights, especially 

 of the rarer groups, when new individuals of such are found, (5) the 

 original cost of collecting specimens, (6) state of preservation, 

 (7) historical interest, (8) if seen to fall, the meteorite is valued 

 higher, especially in the case of nine irons so distinguished. The 

 wisdom of doubling his valuation of these nine falls, or making even 

 a greater increase, is left by Wiilfing as an open question. Con- 

 cerning the stones, he states that there is generally no difference in 

 value between the few not seen to fall and those seen to fall. 



The author here begins a mathematical inquiry into the relative 

 value of the three factors chosen; Group Weight (G), Present 

 Known Weight (A^), and the Number of Owners (B). Following 

 a long analysis with numerous allowances and exceptions, he estab- 

 lishes the exchange value ( IV) in the formula, 



IV = 



VGNB 



Four tables follow for estimating the value of new meteorites: the 

 first is for meteorites having from i to 3 owners ; the second 4 to 8 

 owners; the third 9 to 20; the fourth table being for those of 21 or 

 more owners. The group weight is given vertically and the locality 

 weight horizontally. At the intersection of these lines is a numeral 

 indicating the exchange value per gram, taking the value of Canyon 



