
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 ...

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 fre ...

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 Ligh ...

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 mec ...

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 s ...

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 ...

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 ...

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 drople ...

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 han ...

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 illum ...