4 Metaphors for invisible

" Invisible in the winged machine was a French aviator, reconnoitring the German lines away over Beauséjour.

The belief that "thoughts are things," that the invisible is the only real world, that we are here to be trained into harmony with the laws of God, and that what we are here determines where we shall be hereafterall these ideas are Christian.

Our friends are as invisible as moles.

But 'all things do end,' and so did this; and the silence of the hounds also; and a faint but knowing whimper drove St. Francis out of all heads, and Lancelot began to stalk slowly with a dozen horsemen up the wood-ride, to a fitful accompaniment of wandering hound-music, where the choristers were as invisible as nightingales among the thick cover.

4 Metaphors for  invisible