As mentioned before, I collect slide rules. Now that I have a variety of straight calculating styles, I've been emphasizing special-purpose rules. I have a couple for electronics, for example, and a couple of military ones for artillery calculations.
The other day I lucked into a bundled batch with several unusual rules:
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEixCvHQnu1q3p25GAkhXrBexsIfKDew8CCJ6O1cEcrmOX3ahdTgdzAkcQag7jGfvumv0eNCn3sfEal4QO9WDkIPAR3wtp3Jli9Mdt3NokrDjfMZIOkeyY4DEbAO62nHSsearxe4y0KkUTU/s640/img012.jpg) |
This one will be of interest to my readers. I'm not sure how to use it yet, so feel free to weigh in with ideas. |
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj95BsetA0ojxbYLWTEjlS7Ej2Og4XKISOQZiFzBcJwnz-nCHWsJ51mnYpzhulc3mycKE2MqalCCuOJzyGYMDf-lH2qsEZFchj5_qY7eQB84Rc4Kd4atiRWTCC0sqwYcNDpqizbcYbgRrM/s640/img011.jpg) |
An interesting specimen that's outlived its usefulness. I'm thinking it was thrown in with a set to keep them buying those bulbs. Eventually you used the settings that you habitually did and fixed it in the darkroom. |
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiqCZ3nN7EKDohJew2ENziAO4VMwRYjtldfXZLT4CZ_dof9UKHtwKLDNmGToCaCMc_vQN9nhPJz1EW6mQI1gwgP38vJYVtHbcS6ugFaeq4oxOXTj45xFIt_kpKXhEfw23M3Zo7CA8sd4NQ/s640/img009.jpg) |
This is the one that caught my eye. Still not sure how to use it, but it's fun to speculate on. |