Useful retro tech to make search lights and other light types to illuminate fortifications — dont forget to read my other article on how to apply this  ie use a reflector and harden your lighting

…or elsewhere in my blog where to get gas from I.e methane from a biomass digester .

“Limelight (also known as calcium light)[1] is a type of stage lighting once used in theatres and music halls. An intense illumination is created when an oxyhydrogen flame is directed at a cylinder of quicklime (calcium oxide),[2] which can be heated to 2572 °C before melting. The light is produced by a combination of incandescence and candoluminescence. Although it has long since been replaced by electric lighting, the term has nonetheless survived, as someone in the public eye is still said to be “in the limelight.” The actual lights are called limes, a term which has been transferred to electrical equivalents.”from wiki