y showing who he really is.

"I am Raphael, one of the seven holy angels, which present the prayers
of the saints, and which go in and out before the glory of the Holy
One."

"Then they were both troubled, and fell upon their faces: for they
feared God. But he said unto them, 'Fear not, for it shall go well
with you; praise God therefore. For not of any favor of mine, but by
the will of our God I came; wherefore praise him for ever. All these
days I did appear unto you; but I did neither eat nor drink, but ye
did see a vision. Now therefore give God thanks: for I go up to him
that sent me.'" "And when they arose, they saw him no more."

The picture shows us the moment when the angel suddenly rises from the
midst of the little company and strikes out on his flight through the
air like a strong swimmer. Tobit and Tobias fall on their knees
without, while Anna and the bride Sara stand in the open door with the
frightened little dog cowering beside them. The older people are
overcome with wonder and awe, but Tobias and Sara, more bold, follow
the radiant vision with rapturous gaze.

IV

THE RAT KILLER

The pictures we have examined thus far in this collection have been
reproductions from Rembrandt's paintings. You will see at once that
the picture of the Rat Killer is of another kind. The figures and
objects are indicated by lines instead of by masses of color. You
would call it a drawing, and it is in fact a drawing of one kind, but
properly speaking, an etching. An etching is a drawing made on copper
by means of a needle. The etcher first covers the surface of the metal
with a layer of some waxy substance and draws his picture through this
coating, or "etching ground," as it is called. Next he immerses the
copper plate in an acid bath which "bites," or grooves, the metal
along the lines he has drawn without affecting the parts protected by
the etching ground.

The plate thus has a picture cut into its surface, and impressions of
this picture may be taken by filling the lines with ink and pressing
wet paper to the surface of the plate. You will notice that the
difference between the work of an engraver and that of an etcher is
that the former cuts the lines in his plate with engraving tools,
while the latter only draws his picture on the plate and the acid cuts
the lines. The word etching is derived from the Dutch _etzen_, and
the most famous etchers in the world have been among Dutch and German
artists.