What is art of recording or measuring intervals of time by the photochronograph. -- Pho`to*chron`o*graph"ic (#), -graph"ic*al (#), a. -- -graph"ic*al*ly, adv called?

photochronography — Art of recording or measuring intervals of time by the photochronograph. -- Pho`to*chron`o*graph"ic (#), -graph"ic*al (#), a. -- -graph"ic*al*ly, adv. (Webster's 1913.)

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