Telescope Making

Foucalt Mirror Testing

In order to make the calculations and interpretation of the results of the foucalt test easy, I have written a program that takes the results and then calculates the nearest parabola to the data. It then graphs that final results as is shown in Texereau's book "How to make a telescope".[1]

Program usage

  1. In order to calculate the values hx and hm you'll have to consult Texereau's book for now. Later on I'll describe it here.
  2. Do your foucalt readings. The best is to take 2 readings moving from the inside of focus and the 2 readings moving from outside of focus. Otherwise the readings tend to be one-sided. Average the four readings. Repeat this for each zone.
  3. Input your foucalt readings into the file FOUC.TXT. Here is an example of the FOUC.TXT.
  4. Run the FOUC.EXE program. You can download it here.
  5. Once again consult the book for interpretation of the results.

Source code

The DOS Pascal source code for the program can be downloaded here. (not for commercial use).

References

1. Texereau, Jean. How To Make A Telescope. Interscience Publishers, Inc. 1957.