David for him his tuneful harp had strung,
And Heaven had wanted one immortal song.

This verse was ringing in the ear of Pope, when with equal modesty and felicity he adopted it in addressing his friend Dr. Arbuthnot.

Friend of my life; which did not you prolong,
The world had wanted many an idle song!

Howell has prefixed to his Letters a tedious poem, written in the taste of the times, and he there says of letters, that they are

The heralds and sweet harbingers that move
From East to West, on embassies of love;
They can the tropic cut, and cross the line.

It is probable that Pope had noted this thought, for the following lines seem a beautiful heightening of the idea:

Heaven first taught letters, for some wretch's aid,
Some banish'd lover, or some captive maid.

Then he adds, they

Speed the soft intercourse from soul to soul,
And waft a sigh from Indus to the Pole.
Eloisa.

There is another passage in "Howell's Letters," which has a great affinity with a thought of Pope, who, in "the Rape of the Lock," says,