Spyglass

The spyglass is found in Ultima V. It is used to watch the eight planets of the Britannian Solar System and the comets that sometimes approach them.

Description
The spyglass is the only way to predict a Shadowlord attack on one of the eight cities, thus staying out of trouble with these mighty creatures and the people they use like puppets. Using it during the day, under roofs or in caves is impossible - outside during the day actually only resulting in damage.

After learning about it from the apprentice Dufus, the Avatar finally asked Seggallion in Farthing for the spyglass. Receiving it after correctly answering that the planets represent the virtues, the Avatar now had a very useful tool at hand. Watching the sky at night with it, the hero could see the eight planets of the Britannian Solar System, each representing a city of Britannia. Three comets symbolized the Shadowlords. Until the Shadowlords were vanquished, a comet over a planet meant that the corresponding city was under attack by a Shadowlord and should be avoided for the time being.

With all three Shadowlords destroyed, the spyglass lost its usefulness to the Avatar.

Trivia

 * Another spyglass is on the roof over Lord British's room in his castle. Sadly, it is fixed to the ground, and can't be taken with you. The same goes for several others found on building tops.
 * Telescopes in later Ultima installments were, strangely, only useful to look at the ground.
 * Using the spyglass during the day is a bad idea, as the strong sunlight will hurt the hero.