* * * * *
_The value of the_ SCIENTIFIC AMERICAN _as an advertising medium
cannot be over-estimated. Its circulation is ten times greater than
that of any similar journal now published. It goes into all the
States and Territories, and is read in all the principal libraries and
reading-rooms of the world. We invite the attention of those who wish
to make their business known to the annexed rates. A business man
wants something more than to see his advertisement in a printed
newspaper. He wants circulation. If it is worth 25 cents per line to
advertise in a paper of three thousand circulation, it is worth $2.50
per line to advertise in one of thirty thousand._