Measuring snowfall is a tricky business. Snow blows around, makes drifts, compresses, and melts. To measure snowfall we use snowboards (not the kind you ski on!). These are flat boards located in the gated area next to the Observatory building. And, yes, we do measure snowfall with a ruler. The measuring sticks we use are […]
As anyone who has tried to start a campfire knows, starting a fire is harder than it looks. The focus of sunlight is so precise; it burns away any flammable material as the earth spins and the dot moves thus preventing the card from burning up.
Essentially, nothing. The paper has a coating to prevent it from getting soggy. The recording card can remain in the sunshine recorder for several days without damage. What is more important is to change the card at proper times when the sun is shining to prevent over burn of yesterday’s data with todays.
The “crystal ball” is not used to predict the future (although we wish it could do so). The crystal ball is actually a Campbell-Stokes sunshine recorder. This device was in use on the roof of the building for over 100 years. The sunshine recorder is essentially a magnifying glass that burns a track in a […]
This equipment belongs to the National Weather Service. It measures wind speed and direction ultrasonically. The spikes keep the birds off the equipment.
One of the key aspects of Blue Hill Observatory is that we maintain homogeneous data. By having multiple instruments we are able to ensure data is never lost and that all the instruments are working correctly. Some of the instruments are official, some are back-up, and others are used for educational purposes. We sometimes receive […]
The mercury barometer contains no electronics or moving parts. Its need for calibration is minimal. We are constantly checking the readings from the mercury barometer against other instrumentation to make certain that the device continues to read accurately.