The viewshed is the area that can be seen (ie is in direct line-of-sight) from the specified target locations.

Hat-tippings and cap-doffings are of course of a different nature to more elaborate verbal greetings. In etiquette manuals they may be described as incentives to a conversation, but in practice they seem to have been quite ceremonial.

The pecker mill is likely the fulcrum device developed by Guerrard in 1691.

With that army the British army, in the course of its operations, must have came in contact; and, if that were likely, (may rather if it was impossible to avoid it.) I will ask, whether, under all the circumstances of Europe[…]