VOL. XXXIV.] PHILOSOPHICAL TRANSACTIONS. 133 



A TABLE, showing the strength and gradual increase of the tides of flood and ebb in the river 

 Thames, as observed in Lambeth Reach, off Manchester stairs, and in the middle of the river, 

 witli a new instrument called the marine surveyor, on the 18th of June 1720: it being then the last 

 quarter of the moon, and consequently a neap tide. The movement of the machine 14 inches 

 under water. 



