Page 9: "we must chose," changed to "we must choose,"
Page 12: "acromasie" changed to "achromatism"
Page 15: "inparticular" changed to "in particular"
"supposing, that" changed to "supposing that"
Page 16: "393.4 mm" changed to "393.4 μμ"
Page 20: "for which stars if" changed to "for which stars it"
Page 22: "sphaerical" changed to "spherical"
Page 23: "principal scource" changed to "principal source"
Page 25: "lense with 15 cm" changed to "lens with 15 cm"
Page 27: "Through the spectroscopie method" changed to "Through the spectroscopic method"