On the other hand in the case of ( 2 ) the Physician, though I shall here also see a line ( D′A′E′ ) with a bright centre ( A′ ), yet it will shade away less rapidly into dimness, because the sides ( A′C′ , A′B′ ) recede less rapidly into the fog ; and what appear to me the Physician’s extremities, viz. D′ and E′ , will be not so dim as the extremities of the Merchant.