- Struve, astronomer
- Stubbs 'P.S.' Files
- Stylus, Assyrian
- Sun
- Sunday rivet
- Superheated steam
- Sweden
- Syme, John
- Sympathy of activity
- Talking Books, Mr. Field's
- Tapping square
- Telescope
- refractor, at Berlin Observatory
- reflecting, construction of
- 'Trunnion Vision' model
- views through
- method of casting specula
- Thrift boxes
- Tides, the
- Tolbooth, Old
- Tomb, ancestral
- Tootal, Edward
- Torpedo ram
- Torry, Archie
- Toulon Dockyard
- Trades' Union
- Trafford, Squire
- Trollhätten Falls
- Trunnion turntable telescope