[On the Gaussian curve, remarked to Poincarรฉ:] Experimentalists think that it is a mathematical theorem while the mathematicians believe it to be an experimental fact.
Gabriel LippmannMost of these pictures, taken while travelling, were developed on the mantelpiece of a hotel room, which proves that the method is easy enough to carry out.
Gabriel LippmannThe problem of direct colour photography has been facing us since the turn of the last century.
Gabriel Lippmann