[ *55 ] 
the Tide it will run South, if the Proximity of Land 
or Shoals defes not hinder this Change of Direction. 
The greateft Velocity of Spring Tide in Orkney , in 
the Chanels where it runs quickeft, is about 9 Miles 
an Hour: The greateft Velocity of Neap-Tide is about 
one third or fourth of Spring-Tide. The Tides are 
moft rapid commonly between the third and fourth 
Hour. Spring-T ides acquire a confidcrabie Degree of 
Strength in Jefs than one Hour after their quiefeent 
State begins; Neap-Tides are hardly fenfible in two 
Hours after. 
In fimilar Streights or Chanels, lying in tire fame 
Direction, and fupplied from the fame Part of the 
Ocean, the Velocity of the Streams will be in the 
dirett Ratio of the Bread.h of the Inlets, and the 
Inverfe of the Outlets. 
If a Sound, or Streight between two IOands, or 
Continents, lies in the Direction of the main Body 
of the Tide, the Velocity of the Stream in that 
Streight will be grea r er (all other things alike) than 
in any other adjacent one, not lying in that fame 
Dire&ion. 
If an Illand lies dire&ly in the Tide-way, the 
Stream will divide, or fplit, before it reaches the 
Ifland, into two Branches, one of which will run 
toward one Side or End of the IQand, and the other 
toward the other End of it ; and, in palling by, will 
be reflected a little from the Land. Hence a Vcftel, 
in a Calm, carried along with a ftrong Stream of 
Tide, is in no Danger of touching an Illand, or vift- 
ble Rock, if the Water is deep enough near them. 
If the Tide runs ftronger, or more obliquely, by , 
one End of an Illand than the other, from theftrongeft 
Stream, and from the moft oblique, there will be a 
U 2 languid 
