Transcriber's Notes

The transcriber made these changes to the text to correct obvious errors:

   1. p.   5, accomodate --> accommodate
   2. p.  39, guage --> gauge
   3. p.  46, enbankment --> embankment
   4. p.  63, tought --> tough
   5. p.  68, absorbant --> absorbent
   6. p.  73, persistant --> persistent
   7. p.  77, indispensible --> indispensable
   8. p. 119, aspealt --> asphalt
   9. p. 127, repaid --> rapid
  10. p. 130, Vetrified brick; 105 -->
                           Vitrified brick; 106
  11. p. 130, Virtical --> Vertical