40 THE ROYAL INSTITUTION. [CHAP. I. 



In order to find the most economical method of 

 lighting his Workhouse at Munich, he devised a new 

 way of measuring the relative quantities of lights by 

 their shadows. His arbitrary standard was a London 

 made Argand lamp. He first experimented on the 

 resistance of air to light, then on the loss of light in its 

 passage through different kinds of glass, and in its 

 reflection from a plate glass mirror, then on the 

 relative quantities of oil burnt by different lamps and 

 relative quantities of light emitted by different sub- 

 stances, and lastly on the transparency of flame. 



He made these experiments into a paper on the 

 c Relative Intensities of the Light Emitted by Luminous 

 Bodies,' and it was read 'before the Eoyal Society, 

 February 6, 1794; and on February 20 another paper 

 was read, being an c Account of some Experiments on 

 Coloured Shadows,' and he came to the conclusion that 

 our eyes are not always to be believed, even with respect 

 to the presence or absence of colours. 



For his national and scientific work he received 

 various honours between 1783 and 1794. 



In 1785 he was elected member of the Bavarian 

 Academy of Sciences, which had been established in 

 1758, and he was made chamberlain to the Elector. 



In 1786 the King of Poland, at the request of the 

 Elector of Bavaria, conferred on him the Order of St. 

 Stanislaus. This was done because the statutes of 

 Bavaria did not allow a foreigner to receive any 

 national honours. 



In 1787, when in Prussia, he was made a member of 

 the Berlin Academy of Sciences. 



