It was based on a comparison of 17 manuscript copies.
His first manuscript copy was made in 1598, and he went on to make over a hundred further volumes.
Part of the 385th poem is also missing from all available manuscript copies.
Initially, however, he followed the usual practice of making them available in manuscript copies.
Braille is especially useful in making single manuscript copies of books.
The only manuscript copy to have survived into recent times was burnt in 1875.
No original manuscript copy of Columbus' letter is known to exist.
These were no doubt intended to be inserted into a manuscript copy of the book.
The manuscript copy is undated, but appears to be of the 17th or 18th century.
A number of works survive in manuscript copies only.
