[ngcles]

Hi Hans & All,

I remember reading a similar story in Telescope Making magazine back 20 or 25 years ago involving the very experienced U.S observer and telescope maker Tom Clark (the first amateur to make a 36" -- the "Yard 'scope").

At the time of the incident, he was observing with a 17.5" Coulter Odyssey Dobson mounted Newtonian. After a night of observing he left the 'scope outside until well after dawn. As a result, it was heavily coated with dew in the morning including a very wet primary. In order to quickly dry the mirror before packing the 'scope in the car, he pointed the telescope so the sun was shining down the tube illuminating the mirror. He went away to pack some other things into the car and when he turned back to the telescope a few minutes later, the whole top of the sonotube telescope was ablaze.

Live & learn I guess.

Best,

L.