Can you imagine the type of research those authors in that time had to do? It was mostly from journals written by explorers, farmers, hunters, merchants etc. By our standards Life was hard back them - but it was also much simpler.
An avid reader of his time!
Yes - an avid reader and a researcher when we did not have google. People had to actually ready source manuscripts and journals to get information. Wynn did a wonderful job of describing the Mastiff.
This book is too big to preview so you have to download to read it.