Those issues have advertisements.
Like this one:
You can click to enlarge it, of course, but I'll transcribe the relevant text for you here:
HILAIRE BELLOC on his Fountain Pen: I am writing with a Waterman's Ideal Fountain Pen. The nib is of pure gold, as was the throne of Charlemagne, in the "Song of Roland." . . . Well, then, the pen is of pure gold, a pen that runs straight away like a willing horse, or a jolly little ship; indeed, it is a pen so excellent that it reminds me of my subject - the pleasure of taking up one's pen.
There are so many more things I should like to put up, but I'm going to save them for later. Keep coming back, obviously, for more.