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Webster 1913 Edition
Hornbook
Horn′bookˊ
,Noun.
1.
The first book for children, or that from which in former times they learned their letters and rudiments; – so called because a sheet of horn covered the small, thin board of oak, or the slip of paper, on which the alphabet, digits, and often the Lord’s Prayer, were written or printed; a primer.
“He teaches boys the hornbook.” Shak.
2.
A book containing the rudiments of any science or branch of knowledge; a manual; a handbook.
Webster 1828 Edition
Hornbook
HORN'BOOK
,Noun.