De Witt's Base Ball Umpire's
Guide
A scanned copy of Henry Chadwick's 1875 reference book
Source:  
http://vbba.org/pmwiki/uploads/Education/dewitt_umpire_guide_1875.pdf  

Although much of the material in this book reflects the rules and
customs of the game of the mid 1870s, it still gives us an insight
into the thoughts and ideas of one of the most influential men in
the history of the game.    
Clicking the link below should open up a PDF file on
this website.  If it doesn't work, please go to the source
on the VBBA website.  Thank you.
.