previous next

Spec′ta-cle-gage.

A device for determining the proper distance apart at which the glasses should be placed to exactly suit each individual case.

Spectacle-gages.

In A two glasses are fixed in spring-holders, which slide on a square graduated rod, and may be held by set-screws. These [2258] are moved inward or outward, until an object is distinctly seen by both eyes through the centers of the glasses; being then fixed by the set-screws, the distance is read off on the graduated rod; their hight is adjusted by a central sliding nose-piece.

In B the object is viewed through a pair of goggles, having minute perforations, and attached to two jointed arms; the distance between the two visual axes is indicated on a scale.

Spectacles.

Creative Commons License
This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 United States License.

An XML version of this text is available for download, with the additional restriction that you offer Perseus any modifications you make. Perseus provides credit for all accepted changes, storing new additions in a versioning system.

hide Places (automatically extracted)

View a map of the most frequently mentioned places in this document.

Download Pleiades ancient places geospacial dataset for this text.

hide Display Preferences
Greek Display:
Arabic Display:
View by Default:
Browse Bar: