1. He also invented a heliometer , afterwards perfected by Joseph von Fraunhofer. 2. Both parties used a specially designed heliometer for this purpose. 3. Jean-Charles Houzeau invented in 1871 a heliometer with unequal focal lengths. 4. The two expeditions each had an identical copy of Houzeau's heliometer . 5. He also measured star distances with heliometers . 6. He perfected the use of the heliometer . 7. The star was 61 Cygni, and he used a heliometer designed by Joseph von Fraunhofer. 8. He was educated at Warsaw University and his thesis was on " reduction constants of the Repsold heliometer ". 9. When Phoebe makes herself known to Max, she learns that Max came to steal Dr . Minyak's Heliometer . 10. The first successful measurements of stellar parallax were made by Friedrich Bessel in 1838 for the star 61 Cygni using a heliometer .
