At 11, we had another lecture upon the optical instruments; the solar microscope,1
the telescope, the cylindric mirror,2
and the magic lantern came under consideration; we should have seen likewise the
camera obscura, but the Clouds overshadowed the Sun so much, that the effect could
not take place. I carried down my part to the president, for approbation: was not
quite so indolent the whole day, as I have been two days past.