Hello Peter and all,
Yes, clouds are a significant, perhaps the overwhelming issue with sundials.
Night knocks out half the time and clouds at least half of the remaining
daylight hours. Our BSS colleagues know the problem. The most common sundial
motto is I count only the sunny hours. This is
Hi Brooke,
I remember being fascinated by the instructions on how to make a
camera obscura in Scientific American's _Amateur Telescope Making_.
I've now found the reference on-line: it's in volume 3, p. 419
http://www.willbell.com/tm/tm7.htm
best wishes,
Peter
On 24/03/2015 7:10 AM,
Hi,
In the Last Word section of a recent _New Scientist_ Stephen
Parish raised the question of sundials that might work on cloudy
days...Clearly, polarisation is possible, but I'm doubtful about shadow
casting...
Clouding the issue
* 18 March 2015
* Magazine issue 3013
