Studies in spectrum analysis / by J. Norman Lockyer.

  • Norman Lockyer
Date:
1904
Catalogue details

Licence: In copyright

Credit: Studies in spectrum analysis / by J. Norman Lockyer. Source: Wellcome Collection.

    34/302 page 16
    To sum up then what we have already stated with regard to sound. When we deal with the phenomena of sound, we find that they are composed of dis- tuibailees or vibrations connecting the sender with the receiver; that the sound may vary in pitch ; that the amount of the sound depends upon the amplitude ; that the sound is independent of the material of the sender or the kind of disturbance, so far as pitch goes, but that so far as quality is concerned it is to a certain extent dependent upon the nature of the material and of the kind of disturbance. § 4- Light Waves. We have now to consider that kind of disturbance to which we owe the sensation of light—light being to the eyes of the human race very much what sound IS to the ears. Here again, for simplicity’s sake, let us look at the question in this three-fold point of view. Let us deal with the sender, the receiver, and the medium which connects the sender with the receiver ; first observ- ing that so far as we know at present, not to go too much into detail, there are three kinds of receivers. There IS first of all that marvellous instrument the human eye. lere is next, also a very marvellous thing, the pho- tographic plate. How is It that a few words will awaken in each one of us many memories of our childhood ? Because we saw certain things in our childhood, by means of our
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