In the later cases I have mainly relied upon contemporary accounts and upon my own impressions of some of the trials at which I have been present.
My best thanks are due to all those who have given me valuable and ungrudging assistance. In particular I would mention Major Richardson, who has kindly given me a photograph of one of his trained bloodhounds and has allowed me to quote the description of an actual man hunt with bloodhounds, from his book, War, Police, and Watch Dogs; and Mademoiselle Arlette Clary (and the Daily Mirror) who have supplied me with a photograph of a Paris police dog.
I am further indebted to the late Sir Francis Galton and his publishers, Messrs. Macmillan & Co., who gave me permission to reproduce illustrations from his book on Finger Prints; and to Mr. Thorne Baker and the Daily Mirror for photographs illustrating the use of telegraphy in transmitting portraits.
The excellent drawings of the hairs of different animals were made by my friend Mr. R. M. Prideaux, and are reproduced here by the kind permission of Messrs. Scott Greenwood & Co.
Finally, I would thank the proprietors of Knowledge and the Editor, Mr. Wilfred Mark Webb, for the loan of various blocks and for permitting me to make use of material from several articles of mine on handwriting, which have appeared in that journal.
C. A. M.
White Cottage,
Amersham Common,
Buckinghamshire.