A Porism is a proposition in which it is proposed to demonstrate that some one thing, or more things than one, are given, to which, as also to each of innumerable other things, not given indeed, but which have the same relation to those which are given, it is to be shewn that there belongs some common affection described in the proposition.

Our caricaturist, Lieutenant Fred May, has this week specialised in “three pippers,” as all of the officers in the above collection, have attained to captain's rank, and have all, so we understand, been “through it" […]

The channel is created by bonding the signals from these four pairs.

The Armill, Astrolabe, Dioptra, and Parallactic Instrument of the ancients were some of the instruments thus constructed.