A MACHINE) THAT PROPHESIES 



This machine— the only one of its kind in the world— will predict the tides at any seaport 

 as much as 100 years in advance. It is used in the compilation of the tide tables issued each 

 year by the Coast and Geodetic Survey. A simple turn of the handle will record on the dials 

 the time and height of the water at high or low tide for each day in the year at any selected 

 port, and at the same time trace a tide curve which forms a permanent record of its predic- 

 tions. The machine— an improvement of Lord Kelvin's tide-curve machine— was designed 

 and constructed by the Coast and Geodetic Survey and is a triumph of applied science. 



676 



