CAMBRIDGE, MASS. — One of the two highest priced lots at CRN Auction’s October 1 sale was expected to be just that: Childe Hassam’s impressionistic landscape of a tidal dam and bridge in Cos Cob, Conn., brought $45,140. The pastel on paper painting was signed and dated 1902 and had a long record of exhibitions going back to 1927. The next highest result was a surprise. Selling for $29,280, and far exceeding the estimate, was a large Japanese articulated iron snake, circa 1900. Made of more than 250 small plates, the snake was longer than 7 feet and could be arranged in any position. It was made by a technique known as Jizai Okimono, which goes back to the Seventeenth Century. A carved and painted spoon by Paul Gauguin, which finished at $15,860, rounded out the top three items. All prices quoted include the buyer’s premium; a full report will follow.