10c Washington pair on cover
used; position 71-72R. This is another Ludlow Beebee letter that was deposited in the Boston post office before the mails for New York City closed. It was therefore not necessary to carry it to trainside for delivery to the route agent prior to the train's departure. It is a double-weight letter that traveled over three hundred miles, prepaid with a horizontal pair of 10-cent stamps.
The red "sl-20" rate mark was not an additional collect rate due from the addressee. It was a restatement of the rate paid by the stamps.
Glossary