The Steamship Authority is installing an authentic steamship whistle above the wheelhouse of the ferry Martha's Vineyard this week. Beginning a few days from now, whenever the ferry sails to or from her slips in Vineyard Haven and Oak Bluffs — and perhaps on other ceremonial occasions, as her captains see fit — she will sound a mighty, arresting blast over the waters of Vineyard and Nantucket sounds.

One week ago, the boat line conducted a test of the whistle at its maintenance facility in Fairhaven. Manufactured by the Crosby Steam Gage and Valve Company of Boston, the whistle, about a foot and a half tall, is forged in brass with a downturned mouth. The handle is long and curved, with a soldered repair in the middle. On the casing, you can make out worn-away patents reading 1877, 1896 and 1908.