It was Burke's Peerage.

She had looked into it because of the story of Edryn, finding many mottoes as interesting as the one in the great amber window on the stairs.

Now she turned to the B's and rapidly scanned the columns till she came to the Berkeleys.

For generations there had been an Evelyn in the family.

What a long, long time they had had to shape their lives by their motto, and grow worthy of their family traditions! No wonder that Evelyn had that air of gentle breeding and calm poise like Madam Chartley's.
Mary had already on a previous occasion looked in vain for the name of Ware, and when she failed to find it, consoled herself with the thought that for three hundred years it had been handed down with honour in the annals of New England.