Plate V. The Harvard Classification of stellar spectra. 
It was my hope to get from Mr Pickering a specimen of t 
tra of the different subclasses belonging to the spectral type | 
probably, te the circumstances mentioned in the memoir, I 
yet got an answer to this apply and I therefore take the lih 
reproduce here from the Harvard Annals Vol. ?8 the plate ther 
of the different spectra aecording to the classification used in E 
I have added above the spectra a reference to the principal 
Hydrogen and Helium. 
