BLACK AMERICAN INVENTION
January 10, 1888 - U.S.A.
A U.S. patent was issued for the railway signal to the Black American inventor, A.B. Blackburn (No. 376,362). The type of signal was that designed to be operated by the wheels of a train. A lever was depressed as a train wheel travelled over it, to remotely operate an alert through a mechanical linkage upon the passing of the train. It was designed for use upon a single track railway line for trains passing in one direction. To provide a signal for trains passing in the opposite direction, a similar apparatus would be applied on the opposite rail. This patent was an improvement in mechanical design of his earlier patent No. 309,517 on 23 Dec 1884, in which he also described how a gong was activated to provide the alert.
RECORD “SINGLES”
January 10, 1949 - 7-inch diameter 45 rpm, U.S.A.
RCA introduced the “single,” the 7-inch diameter 45 RPM record in the U.S.A single could play eight minutes of sound per side. Columbia had introduced the 12" long-playing vinyl 33 RPM as a new format the previous year. These formats greatly improved upon the 78 RPM records, which were limited to only 5 minutes per side on a 12" disk. Vinyl records were less fragile, and had a lower level of surface noise, but needed new playing equipment. RCA subsequently manufactured a record-player with a wide-diameter spindle to automatically play a stack of singles. The 45 RPM, 7" record was favored by the young, and became successful with the onset of rock and roll. In the UK sales of 45s overtook 78s early in 1958.
MEMBER LOGIN
RANDOM QUOTES
Happiness
by Thomas Jefferson
"...Our greatest happiness does not depend on the condition of life in which chance has placed us, but is always the result of a good conscience, good health, occupation, and freedom in all just pursuits...."
No Man is Above the Law
by Theodore Roosevelt
"..."No man is above the law and no man is below it; nor do we ask any man's permission when we require him to obey it. Obedience to the law is demanded as a right; not asked as a favor."..."
RANDOM FACTS
Harvard Medical School
about Eyesight Myth and Fact
Myth: Staring at a computer screen all day is harmful to the eyes.
Fact: Spending the day staring at a screen can tire or strain your eyes, but it will not hurt them. Make sure lighting doesn't create a glare on your screen. When spending long periods at your keyboard, take a break now and then to rest your eyes to reduce fatigue. Also, don't forget to blink. Your eyes need to stay lubricated to feel comfortable.
Cancer Facts & Figures
about Besides Lung Cancer
Besides lung cancer, tobacco use also increases the risk for cancers of the mouth, lips, nasal cavity (nose) and sinuses, larynx (voice box), pharynx (throat), esophagus (swallowing tube), stomach, pancreas, kidney, bladder, uterus, cervix, colon/rectum, ovary (mucinous), and acute myeloid leukemia.
Spacecraft :
Choose Your Color :
Category Information : Spacecraft
This is our Spacecraft category. If you are interested in Spacecraft, feel free to browse these listings. If you have a site that fits within this category, Submit it for inclusion.
NASA'S vision: To reach for new heights and reveal the unknown so that what we do and learn will benefit all humankind. To do that, thousands of people have been working around the world -- and off...
Associated transformers is a leading Transformer Manufacturing Company in Tamilnadu, India. Lead the industry in manufacturing of various types of transformers like Distribution, Furnace/ Rectifier...
Has grown into the largest supplier of live entertainment for weddings, corporate events and private parties in the UK. With over 90,000 previous customers and an artist roster of over 1750 bands, ...
Carvers for Conservation was started to introduce the people conserving the habitat of migratory birds to the premier bird sculptors in the world. My intention was to be mutually beneficial to the ...
Friendship poems happen to be just the best medium of expressing eternal friendship to that special friend. You can let all the love and affection you possess flow out, right onto the paper lying in front of you, through a sweet little friendship.
Search engine is the term with which we are accustomed with very much. But the web directory is not that same. The web directories are older than search engines according to the time of their invention.