SCIENCE. 



FRIDAY, JANUARY 22, 1886. 



COMMENT AND CRITICISM. 

 Dr. Persifor Frazer of Philadelphia has re- 

 cently applied composite photography to test- 

 ing the genuineness of signatures. He first ob- 

 tained by composite photography a standard 

 signature, and then he compared this with the 

 signature in dispute. In the case of the composites 

 of the heads on coins, or of portraits, it is tacitly 

 assumed that the variation observed is due to a 

 difference of the subject at different times, or to 

 the different impression which the same subject 

 makes on different artists. In the case of hand- 

 writing, however, the will-power of the writer 

 attempts to reproduce exactly a certain combina- 

 tion of symbols in the same order as that usually 

 performed ; but the accidental physical obstacles 

 or mental influences render this impossible. A 

 priori, it would seem likely that a composite of 

 a larger number of signatures would show an 

 individuality little less distinct than the race, 

 family, or pathological characteristics which thus 

 far it has been the aim of those who have used 

 this method to portray. In point of fact it turns 

 out to be the case ; but what was not foreseen is 

 equally true ; viz., that the very variations which 

 appear on the plate, either as very faint lines or 

 as blurs, furnish the most valuable aid in deter- 

 mining whether- or not two pieces of writing are 

 by the same hand. On examining carefully each 

 letter of a composite made from a large number 

 of signatures, it is found that the variations in 

 writing a letter at different times, are confined to 

 certain of its parts, and are not distributed equally 

 over the entire field. Thus not only is there more 

 uniformity in letters and parts of letters which lie 

 close to the line, but in the upper loops, dots, and 

 crosses, the tendency in all cases thus far ex- 

 amined is towards variation in one, or at most 

 two, directions ; and these are restricted more 

 than one would suppose, who regards without 

 critical analysis the writings from which the com- 

 posites were made. It would be premature at this 

 time to say with what certainty one might tell, 

 after an extensive experience of the use of this 

 sort of analysis, that two writings were or were 



No. 155. — 1S86. 



not by the same hand. But the great gain, after 

 all, is not altogether in the certainty which the 

 method renders possible (though this cannot be 

 ignored), but in the fact that it removes the judg- 

 ment on affairs as delicate and often as important 

 as the identification of handwriting from the pos- 

 sible bias of personal expert opinion, and allows 

 the testimony of the photograph to be weighed by 

 judge and jury like any other testimony. So far 

 as Dr. Frazer has yet been able to observe, it is im- 

 possible to write naturally the signature, or even 

 the hand, of any other person, without showing- 

 numerous discrepancies with the composite plate. 

 The essential requisites to making the plate are of 

 course as many signatures as possible, about which 

 there can be no suspicion. In order to make the 

 letters overlap as much as possible, it is some- 

 times found necessary to photograph them at dif- 

 ferent distances from the camera. It is a curious 

 fact, that, when a man is obliged to restrict his 

 whole signature to a space less than that to which 

 he is accustomed, he will insensibly make a change, 

 which is usually a close approximation to a re- 

 duced scale. 



In the number of Science for last week we 

 noticed the railroad running across the deserts 

 of Asia towards Merv and Bokhara. This week 

 we wish to call attention to the first well-devel- 

 oped plan for the construction of a railway con- 

 necting the interior of Africa with the Atlantic 

 Ocean. On the 23d of December, 1885, an agree- 

 ment was made at Brussels, between the inde- 

 pendent state of Kongo, and delegates from the 

 Kongo railway company of Manchester, granting 

 to this company the right to construct a railway 

 to connect the upper and lower Kongo. The 

 delegates of the English company were Messrs. 

 Hutton, M.P., president of Manchester chamber 

 of commerce ; Mackinnon, director of the British- 

 Indian steam navigation company ; and Stanley. 

 The directors of the railway company are the 

 three delegates before mentioned ; and Messrs. 

 Adamson, president of the ship-canal to connect 

 Manchester with Liverpool ; Jacob Bright ; Lord 

 Egerton ; Sir James Ferguson, M.P., and former 

 governor of Bombay ; W. H. Houldsworth. M.P. ; 

 and H. M. Steinthal of Manchester. The capital 



