This surcharge is by a Commercial Controls Corporation meter slug. They were the successors of the National Postage Meter Corporation. It's not often seen on postal cards as metered usages go.
This metered usage is nice because the card is also cancelled. This is often not not so with metered cards. Corporations like Central Scientific Company probably had many hundreds or thousands of postal cards with preprinted forms in stock when rates changed.
Place mouse on image to see the reverse side of the card.