Reading Glass Fire Lighting.

Ascobis

Forager
Nov 3, 2017
128
69
Wisconsin, USA
I grew up in Arizona. Lighting a fire with a magnifying glass there is trivial. Now I live at 43 degrees North and all those skills developed burning innocent ants are of no avail. In defiance of solar geometry, I got a surplus Fresnel lens from an overhead projector. It works, but it won't fit in an Altoids tin.

Like solar stills, magnifying glasses for fire-starting have their place. That place is the sub-tropics and tropics.
 

shaggystu

Full Member
Nov 10, 2003
4,345
30
Derbyshire
I grew up in Arizona. Lighting a fire with a magnifying glass there is trivial. Now I live at 43 degrees North and all those skills developed burning innocent ants are of no avail. In defiance of solar geometry, I got a surplus Fresnel lens from an overhead projector. It works, but it won't fit in an Altoids tin.

Like solar stills, magnifying glasses for fire-starting have their place. That place is the sub-tropics and tropics.

43° isn't that far North, most of Europe is more northerly than that (Bilbao and Marseille are both at pretty much 43°), making fire with a magnifying lense/parabolic mirror is perfectly viable way above 43° latitude.
 

John Fenna

Lifetime Member & Maker
Oct 7, 2006
21,917
1,407
63
Pembrokeshire
005 (2014_12_26 19_57_08 UTC).JPG focus the hot spot (2015_01_01 06_41_25 UTC).JPG focus the hot spot (2015_01_01 06_41_25 UTC).JPG Yup - I too have used burning lenses in Britain - to good effect :)
A condom full of water makes a good lens as well.....
 
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oldtimer

Full Member
When I lived in the sub-tropics, I regularly used to light my pipe with a magnifying glass. It was so much easier when the wind was blowing - which was most of the time. However, I learned the trick in the South of England where I grew up: it just took a little longer.

We have had fires in the South of France started by the sun shining through carelessly discarded bottles. This is not unknown in England.

Interesting to note Le Loup, that if you were female and were La Loupe, you'd be French for magnifying glass (as used by jewellers and watchmakers)!

Thanks for the video.
 

Ascobis

Forager
Nov 3, 2017
128
69
Wisconsin, USA
43° isn't that far North, most of Europe is more northerly than that (Bilbao and Marseille are both at pretty much 43°), making fire with a magnifying lense/parabolic mirror is perfectly viable way above 43° latitude.
I'm happy for you. With your gentle nudge, I shall try again. One question: winter or summer?