The brush is needed to whisk eraser dust away. The chief advantage of this eraser is that it may be sharpened to a point to erase a very small area.

What were the various image macros? ... [img-foo]: See Image Macro. A list of official [img-foo]s are above, but any common image that's used often can replace foo. [img-motorcycle.jpg] for instance.

The night-owl,—a mug-shaped instrument, with an orifice in its side, through which a whistle is inserted,—when used, is partly filled with water, to give the tremulous owl-hoot sound.

While Adobe's Acrobat Reader, Macromedia's Flash player, and other common plug-ins suggest themselves the moment you encounter a site that requires them, other browser helpers are harder to find.