Cai Kun;0; 
Cartwright;58; 
Cathode;133; 
Cayley;215; 
Central processing unit;291; 
CFC;529; 
Chebyshov;714; 
Cherenkov;782; 
Chips;848; 
Clipart;960; 
Clipper;1105; 
Cockerell;1279; 
Colors of the spectrum;1345; 
Compass;1525; 
Compatible;1572; 
Compound;1741; 
Compressor;1865; 
Condenser;2003; 
Controls;2212; 
Cooke;2340; 
Co-ordinates;2420; 
Copernicus;2506; 
Cugnot;2615; 
Cursor;2818; 
Cylinder;3051; 
D2-MAC System;3199; 
Daguerre;3580; 
Daguerrotype;3665; 
Daimler;3915; 
Daisywheel printer;3992; 
Database;4064; 
Davy;4200; 
Demodulate;4263; 
Density;4411; 
Dieckmann;4536; 
Diesel;4592; 
Digital to analog converter;4854; 
Digital;4666; 
Digitalize;5002; 
Dioptric;5126; 
Displacement;5188; 
Drais;5450; 
Drebbel;5491; 
DVD-Plus;5554; 
DVD-RAM;5669; 
DVD-ROM;5852;