ions
imparted to the air by the flapping of their wings. This may be rendered
evident by observing, that the noise always ceases when the insect
alights on any object. The sirene has been ingeniously applied for the
purpose of ascertaining the rate at which the wings of such creatures
flap. The instrument being brought into unison with the sound produced
by the insect, indicates, as in the case of any other musical sound, the
rate of vibration. In this way it has been ascertained that the wings of
a gnat flap at the rate of 15,000 times per second. The pitch of the
note produced by this insect in the act of flying is, therefore, more
than two octaves above the highest note of a seven-octave
pianoforte.--_Lardner's Handbook_.

A WELCOME SACRIFICE.

BY THE REV. JAMES GILBORNE LYONS, LL.D.

Vain is the blood of rare and spotless herds,
Pastured in meads where blue Clitumnus shines;
Vain are sweet gums from lands that Indus girds,
Or diamonds sought in deep Brazilian mines;
Vain are Iberian fruits, and perfumed flowers,
Rich as a Grecian sunset's purest dyes,
If deemed, when worship claims thy holiest hours,
For HIM IN HEAVEN fit gift or sacrifice.

The flocks that roam on thrice ten thousand hills,
Each living thing that moves on shore and sea,
The gems and gold which gleam in caves and rills,
Saba's low shrub, and Lebanon's proud tree,
The fragrant tribes that spring on cliff and field,
That flush the stream, or fringe the smooth lake's brim,
Breathe, burn, and bloom, at His high will revealed,
And own with joy their Light and Lord in Him.

Our gains are His, and, laid before the Cross,
These must of our oblations form a part,
But oh! the choicest ores and gems are dross,
If brought without that pearl of price--THE HEART.
The poorest serf who fears a tyrant's nod,
Whose inmost soul hard bondage racks and wrings--
That toil-worn slave may send unseen to God
An offering far beyond the wealth of kings.

Come thou with breast from pride and passion freed,
Hands which no stain of guilt has ever soiled,
Feet swift and strong for every gentle deed,
Faith, hope, and truth, by sordid crowds unspoiled;
Come with a spirit full of generous love
For all beyond, and all below the skies:--
Make ready thou, for Him who reigns above,
The Christian's gift--A LIVING SACRIFICE.

'MY TRA