It seems impossible to calculate correctly as to what length of time must elapse before the reply to the letter one sent by the last mail can reach one.

He who waits is always premature in the calculation he makes.
The mail should be due at a certain date, one is so sure.

The letter could be written on such a day and posted at once.

But the date calculated for arrives, passes,--the answer has not come.

Who does not remember?
Emily Walderhurst had passed through the experience and knew it well.
But previously the letters she had sent had been of less vital importance.