1849 introductions

pointed fastener with a locking mechanism, often used to secure clothing and cloth diapers

Methylamine, also known as methanamine, is an organic compound with a formula of . This colorless gas is a derivative of ammonia, but with one hydrogen atom being replaced by a methyl group. It is the simplest primary amine.

hard, round-crowned hat with a narrow rolled brim

type of conical projectile for mid 19th century rifles

chess set used for competitive play

theorem

thumb|An I-beam used to support the first floor of a house An I-beam is any of various structural members with an - (serif capital letter 'I') or H-shaped cross-section. Technical terms for similar items include H-beam, I-profile, universal column (UC), w-beam (for wide flange), universal beam (UB), rolled steel joist (RSJ), and double-T (especially in Polish, Bulgarian, Spanish, Italian, and German). I-beams are typically made of structural steel and serve a wide variety of construction uses.

13 month solar calendar

gold dollar coin of the United States depicting the goddess Liberty, minted from 1849 to 1889

transcription system developed by Lepsius for Egyptian hieroglyphs and other African and Asian languages

US $20 gold coin

Gold coin issued by the United States

stamp series issued in Belgium in 1849