Cybersecurity refers to the preventative techniques used to protect the integrity of networks, programs and data from attack, damage, or unauthorized access.
Pencils were invented in 1795 by a French scientist named Nicolas-Jacques Conte. He used a mixture of graphite, clay and water baked in a kiln to create the lead of the pencil. He then housed this mixture in a wooden frame for writing. Continue Reading.
A mechanical pencil or a propelling pencil is a pencil with a replaceable and mechanically extendable solid pigment core called a lead /ËlÉd/. The lead, often made of graphite, is not bonded to the outer casing, and can be mechanically extended as its point is worn away. Other names include automatic pencil, drafting pencil, technical pencil, click pencil, clutch pencil, leadholder, pacer, pen pencil, and lead pencil. Mechanical pencils are used to provide lines of constant width without ...