The first fountain pens just weren’t portable, unless you liked ink-stained clothes, but soon after the turn of the twentieth century improvements to feeds, screw-on caps and safety pens meant that they could be carried, provided they were kept upright.  As fixed clips hadn’t arrived on the scene, pen and accessory manufacturers tried various solutions.  In many ways, the removable accommodation clip was the most successful, but it did have a tendency to scratch caps.

Mabie Todd’s answer was the Swan Metal Pocket:

At first glance it seems like an unnecessarily clunky solution but actually it’s eminently practical.  Though well made it is light.  The clip will attach firmly to any thickness of material from cotton shirt to tweed jacket and the pen is held securely but lightly, with no risk of marking it.

The clip is stamped with a beautiful Swan emblem; as this part would be visible, Mabie Todd wasn’t going to miss the opportunity to advertise their products.

The proof of the pudding is in the eating.  These accessories sold in huge numbers, many of them still around today.  The proof that this one was well used is on the back, where it has been rubbed down to the bare metal with years of use.

Though almost completely superseded by the modern fixed clip, the Swan metal pocket will still provide a means of carrying our clipless pens today.