326 



ANNUAL. REPORT SMITHSONIAN INSTITUTION, 192 8 



traverse of the ground was as likely to be successful as any other. 

 The use of the rod in medieval mining was described by many 

 authors, and they often dismissed it as futile, as Agricola (1556) 

 from mining practice and the Jesuit, A. Kircher (1678), after some 

 experimental tests. 



In the Middle Ages the rod was used for the detection of all sorts 

 of materials — water, buried treasure, landmarks, metals, and mur- 

 derers. For example, Aymar* in 1692 by the rod traced some mur- 

 derers from Lyons down the Khone Valley until one of them was 

 found at Beaucaire. The man was arrested, charged with the 



Figure 1. — Divining for metallic veins in the sixteentli century 

 Preliminary operations of the miner. Two men have divining rods 

 (A) ; one is cutting a rod, others are delving and discussing the plan 

 of operation. From De Re Metallica of Agricola. Reproduced from 

 Old Trades and New Knowledge (1026), by Sir William Bragg, K. B. 

 E., D. Sc, F. R. S., director of the Royal Institution, by kind permis- 

 sion of G. Bell & Sons (Ltd.), the publishers 



murder, and confessed. Aymar was employed in a later murder case ; 

 he was led blindfold over ground saturated with the blood of the 

 victim ; but the rod gave no indication, and he was ultimately found 

 to be a fraud. His first success was probably due to his knowing 

 who the murderers were and tracking them by ordinary means, as 

 was suggested by Ozanam and Montuela (Recreations in Mathe- 

 matics, Vol. IV, 1803, p. 263). 



The use of the rod has been generally abandoned except for water, 

 though it has been extensively employed in America in the search 



