s as z.

The act of observing or taking notice; the act of seeing or of fixing the mind on any thing. We apply the word to simple vision, as when one says, a spot on the sun’s disk did not fall under his observation; or to the notice or cognizance of the mind, as when one says, the distinction made by the orator escaped his observation. When however it expresses vision, it often represents a more fixed or particular view than a mere transient sight; as an astronomical observation.

Notion gained by observing; the effect or result of seeing or taking cognizance in the mind, and either retained in the mind or expressed in words; inference or something arising out of the act of seeing or noticing, or that which is produced by thinking and reflecting on a subject; note; remark; animadversion. We often say, I made the observation in my own mind; but properly an observation is that which is expressed as the result of viewing or of thinking. In matters of human prudence, we shall find the greatest advantage by making wise’ observations on our conduct.

Observance; adherence to in practice; performance of what is prescribed. He freed the christian church from the external observation and obedience of legal precepts not formally moral.

In navigation, the taking of the altitude of the sun or a star in order to find the latitude.