No. 54110. 



Spectrum Apparatus. Zeenian Phenomenon. 



509 



54103,54108. 1:8. 



54 110. 1 : 9. 



54.101. Direct-vision Spectroscope after Janssen-Hofmann, Figure (Fr. phys. Techn. II, 

 2, Fig. 2818 [II, 904]) 



Observing telescope and gap-tube with 22 mm aperture, 182 mm focal length and approx. 

 power 7. Gap with micrometer screw and comparison prism. On the middle cylindrical portion, in 

 which the prism-system is fixed, a telescope with photographic scale is arranged laterally. The move- 

 ment of the observing tube is carried out by a micrometer screw with a view to controlling the very 

 extended spectrum, while focussing is carried out by rack and pinion. The apparatus is mounted on 

 a stand having universal motion. Dispersion from A H 1 , approx. 9. 



54.102. - - idem, with two prism-systems and twice the dispersion (approx. 18) .... 



54.103. Interference Spectroscope after Lummer-Gehrcke, Figure (Verhandl. d. Deutschen 

 Physikal. Gesellschaft 9, 1907, p. 529), also adapted as an ordinary spectrum apparatus 

 with low dispersion and, in conjunction with the necessary accessories, for demonstrating 

 the Zeeman effect 



The resolving power of this apparatus is extraordinarily high so great that '/too of the distance 

 of the D-lines can be resolved. The apparatus has a simple gap, one ocular with cross wires, one plane 

 parallel glass strip and a reflecting prism. It is for use as a low-dispersion spectrum apparatus. 



54.104. Wollaston Prism, in Mount, for sliding over the ocular of the Spectroscope 



54.105. Wollaston Prism with 1 / t wave-length plate, in mount 



54.106. Spectrum Tube with H or Hg 



54.107. Spectrum Tube Stand with Condenser and Electromagnet for 6 volts, for demonstrating the Zeeman effect 



54.108. idem, with double Electromagnet, Figure, for the Zeeman transverse and longitudinal effect 



54.109. Interference Spectroscope as No. 54,103, for use as a Spectrum Apparatus with strong 

 dispersion ................................... 



The apparatus has a second flint glass prism and direct-vision prism body which can be switched 

 into operation, simple gap, one Ramsden ocular of 28 mm and a similar one of 19 mm focal length 

 with cross wires and plane parallel glass strip. 



54.110. Grating Spectroscope for the Zeeman Phenomenon, after Weinhold, Figure, with 

 a Eowland Plane Grating and an Electromagnet, for observing in a longitudinal direction 

 and in a direction transverse to the lines of force ................ 



The apparatus is arranged in such manner that the observing telescope can be shifted over for 

 observations with the right or left eye. The electromagnet can be rotated about its vertical axis 

 and, at the positions in which the magnetic axis coincides with the axial direction of the collimator 

 tube, or perpendicular to this, it can be clamped with a securing pin. If a mercury spectrum tube, 

 fixed between the magnet poles, is illuminated by a spark-coil, it shows the characteristic green line 

 of mercury in a simple manner as long as the magnet is unexcited, but an extended line is shown 

 when (lie magnet is excited. In addition the observed line of the spectrum is polarised. In observing 

 perpendicular to the lines of force three single lines result (a triplet) which are rendered the most plain 

 when the S6narmont Prism, given in with the apparatus, is placed on the ocular which, acting as an 

 analyser, shows two spectra which are brought above each other by rotating; two lines then appear 

 in the deflected polarised part, and a single line in the unpolarised. In observing in the direction 

 of the lines of force a doublet is produced consisting of two circular -polarised lines. 



. s. d. 

 16. 0.0 



20. 0.0 



18. 0.0 



1. 7. 



2. 0.0 

 0. 7.0 

 5. 5. 



10. 10.0 



32. 0.0 



60. 0. 



Cl. 6050, 5533. 



