What makes this book ultra rare: - Two printing errors. found only in copies printed early in the first press run. (see photos): - First, on page 157 "Percy" is misspelled "Perry" - Second, the large "2" is missing from the spine of the dust jacket. - Both errors were corrected early in the first printing of the first American Edition. On the copyright page, two full number lines starting with "1 "and ending in zero respectively and the number 37 together indicate a first printing ..and the words ''First American Edition'' tell us what this is a first printing of.