Observatory, astronomical—in Persia [103]
Oerstedt, forerunner of telegraphy [18]
Page, his discovery [52]
Phantasia [6]
Photography, forerunners of [16]
Porta, inventor of the camera obscura [16]
Railway nets, extensive [100]
Reis, his invention [52]
Scheele, forerunner of photography [16]
Schönbein prepares collodion [17]