Many of the nobles and senators, although of great age, mounted more than once to the top of the highest church in Venice, in order to see sails and shipping … so far off that it was two hours before they were seen without my spy-glass …, for the effect of my instrument is such that it makes an object fifty miles off appear as large as if it were only five miles away. ... The Senate, knowing the way in which I had served it for seventeen years at Padua, ... ordered my election to the professorship for life.