254 Remarks on Mr Facov’s Obſervations.

nerdireded in fect. X. It is this€eir- cumítance which gives occaſion to the gather of the wheels forward; and Mr Jacob is miſtaken, when he makes the bend of the arms, or gather of the wheels, to depend wholly upon, or be regulated by, the diſh or cavity of the wheels; and‘when he alledges that the diſh of a wheel neceſſarily requires a

bend in the axle arm, to give it a mo-

tion ſtraight forward. Whatever the:

diſh of a wheel is, the face of it will al- ways be perpendicularly cut by the centre line of the buſhes, if the wheel be truly made, and truly buſhed. Itis therefore the taper of the arm, and not the cavity of the wheels, which is the immediate cauſe of that outward preſ-

iure, which makes it neceſlary to bend

the

litis R—

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