| | WPS:Products:Model 23 (Site not responding. Last check: 2007-10-24) |
 | | In the sky is the window of a Geiger-Mueller tube; with each disintegration of Cesium-137 within the trinitite a beta particle is emitted; those that reach the G-M tube cause a small spark within the tube, made audible with electronics inside the Model 23. |
 | | Each same spark, processed by other electronics within, triggers one view of each of the frames on the film strip, projected badly on a tiny viewing screen visible in the viewing hood, after the red start switch is pressed. |
 | | The front panel is a quarter-inch slab of brass, reverse-etched in an eight-hour process to leave raised lettering, the varied colors due to copper and zinc dissolving in the etchant at different rates. |
| www.wps.com /products/Model-23 (272 words) |