Transcriber's Note

A duplicate heading "INDEX" has been removed from the text.

The following apparent printing errors have been corrected:

Punctuation in the index has been regularised.

The following printed erratum has been incorporated into the text:

Erratum.

p. 48, l. 18, for those, read that.

The following possible errors have been left as printed:

Index entries for U and V were printed in reverse order.

There are many inconsistencies in the text, including:

In addition, upper and lower case and small capitals are used for compass directions. The table of Siamese years on p. 251 uses apostrophes inconsistently.