Boothbay Harbor Memorial Library was more crowded with book lovers than usual on Thursday, Aug. 22 when it hosted Ken Gloss of Brattle Book Shop and PBS’ “Antiques Roadshow.”

Gloss was there to lecture about rare books, but his style was less lecture and more wit as he recounted interesting and funny stories from his many years operating Boston’s Brattle Book Shop.

The bookshop dates to 1825 and was owned and operated by his father, George, from 1949 until his death in 1985. Ken Gloss has been in the business for more than 40 years, providing information to those wishing to buy or sell books.

His expertise is well known to “Antiques Roadshow” viewers. He became one of its regular appraisers in its fifth season and offered to provide appraisals for those who brought a book to the event.

Gloss started his talk by asking, “What is a valuable old book?” and answering, “It depends on the book.” Not every old book is valuable, he said, and handed around a page from a book published in the 1490s. “What was a dull, uninteresting book in the 1500s is still a dull, uninteresting book now.”

He spoke about first editions and explained the elements that give a book its value. Significance from a historical, scientific, or literary standpoint is important, Gloss advised. Condition plays a role, too, and a paper dust jacket can add value.

Since “a lot of collecting is prestige,” a book signed by the author can be more valuable than one without a signature, Gloss said.  And some signatures are extremely valuable. Gloss told the guests that, since J.D. Salinger rarely signed a book, his signature on a copy of “The Catcher in the Rye” can add thousands to the value.   

Anticipating a question from attendees, he asked: “What book would I most like to find?” and answered with one word: “Tamerlane.” The 1827 poem is in a pamphlet written by Edgar Allen Poe. There are few original copies and the last one was found in a box of old books 20 years ago by an antiques dealer who sold it for more than $100,000.

Gloss said the fun of collecting is in learning about the item and he is often asked to visit homes to provide estimates. Gloss held up a family Bible one guest provided. “The Bible is the most commonly printed book of all time,” Gloss told the crowd. “We get hundreds of calls about Bibles each week. And in almost all cases, the value of it is in the significance to the family, not as a rare or historical book.”

Guests queued for appraisals of their own books after Gloss ended his talk. Among the books he saw were a few in the $300-$500 range. Hear more of his stories in his podcast “Brattlecast” at https://podcasts.apple.com/us/podcast/brattlecast-a-firsthand-look-at-secondhand-books/id1295728623

The podcasts are also available on iTunes or from Google Play. For more information about rare books, Gloss can be reached at Brattle Book Shop, (617) 542-0210 or (800) 447-9595.