P. [490]. 'it' changed to 'it's'.

P. [542]. 'main ained' changed to 'maintained'.

P. [550]. 'of' added in 'of the Alps'.

P. [610]. 'de-defeated' changed to 'defeated'.

P, [611]. 'instal' changed to 'install'.

P. [611]. Added missing page number '174'.

Fixed various punctuation.