Category: Questions for the Keeper

  • Hudson River water temperature

    In springtime, fisherman are concerned about water temperature in the Hudson River. When the the water temperature in the Tappan Zee reaches 50 degrees, migrating striped bass transition from brackish to freshwater and continue their journey upriver where eager fisherman await them with bait and lures. An easy way to learn about water temperature is…

  • Freshets & Ice Gorges

    Recent storm surges raised the question of when the Lighthouse last saw flood levels anywhere near these heights. In addition to storm surges, floods in the Hudson are often due to freshets. A freshet is the sudden increase in river levels caused by melting snow and ice, usually occurring during March or April. Flooding from…

  • First aid to navigation on the Hudson?

    A volunteer onboard the sloop Clearwater recently posed the question: when was the first aid-to-navigation established on the Hudson River? To address this question, I relied on Jim Crowley’s Lighthouses of New York. As it turns out, the answer is not clear-cut. Affixing a specific year is difficult since the first aids-to-navigation predated the arrival…

  • Question for the keeper: what's that?

    The tug Glen Cove pushed a barge downriver carrying two massive A-frame structures of corrugated sheet metal. A peek through the binoculars revealed that the A-frames housed four large cylindrical mechanisms. My guess: cooling towers. A quick Google Search took me to the tugster blog for the answer: cooling towers built upriver in Coeymans, NY…

  • Question for the Keeper: outer island

    The Fischer Family from North Carolina wrote to inquire about the outer island adjacent to the lighthouse. We’re wondering if you might share some information about who helped create this magical space: who created the island, who planned the deck (with the backs of the side benches hinged to lift up! (for what purpose, we wonder), who planted…

  • Question for the Keeper: meteor shower radiant

    Last week’s Perseid meteor shower prompted the following question: Why do meteor showers appear to radiate from single point in the sky? Meteor shower particles are actually all traveling in parallel paths and at the same velocity, but they appear to an observer below to radiate away from a single point in the sky. This…

  • Star-gazing and lighthouse pollution

    A lesson from lighthouses on light pollution: A hometown friend of mine asked me (jokingly) if I ever turn the beacon off for star-gazing. Well, of course not, for obvious reasons, especially obvious to commercial cargo vessels trying to navigate the narrow river channel at night. Even so, it’s not necessary to turn off the…

  • Question for the Keeper: ripples

    Question: Why are some patches of the river’s surface smooth and other rippled during a drizzle? This question arises from observation of the texture of the water’s surface. In a drizzle, rain droplets ripple the surface of the water. Although the rain is falling uniformly, smooth patches appear of the water’s surface amidst the ripples.…

  • Question for the Keeper: tide

    How does the tide clock work? Does high tide occur at the same time everyday? At the lighthouse, a tide clock adorns the kitchen wall above a regular analog timepiece. The tide clock has a single hand that sweeps around its face pointing towards high tide or low tide or somewhere in between. The hand…

  • Question for the keeper: fireflies

    Why do fireflies flash? At dusk, the trail to the lighthouse turns into a corridor of flashing light as fireflies emerge for their nightly mating ritual. The fireflies are so numerous that they illuminate the footpath on a moonless night. The flashing light is the firefly’s way of attracting a mate. For many species of…