Internet (1969)

Advanced Research Project Agency (ARPA) develops  the first computer network

In 1963, the Advanced Research Project Agency (ARPA) unit, set up by the U.S. Defense department, began to build a computer network, Driven by fear of the Soviet nuclear threat, it aimed to link computers at different locations, so researchers could share data electronically without having fixed routes between them, making the system less vulnerable to attacks-even nuclear ones.
           Data was converted into telephone signals using a modem (modulator-demodulator), developed at AT&T in the late 1950s. In the 1960s, key advances were made, including "packet switching"-the system of packaging, labeling, and routing data that enables it to be delivered across the network between machines. Paul Baran (b. 1926) proposed this system, which broke each message down into tiny chunks. These would be firesd into the network, which would then root ("switch") the various pieces  to the desired destination. So, if the chunks of a message were travelling from Seattle to New York via Dallas, but Dallas suddenly went offline, the metwork would automatically route via Denver instead. Different parts—or "packets"—of a message would go by different routes, before being destination, even if they arrived in the wrong order. Baran published his concept in 1964, and five years later the new network—called ARPANET—went live.

          As the threat of nuclear war receded in the early 1970s, ARPANET was renamed the Internet and effectively opened to all users. Since then, the development of e-mail, the creation of the World Wide Web, and browser technology has enabled the Internet to become a rich communications facility.

"Getting information off the Internet is like taking a drink from a fire hydrant."

Single Lens Reflex Camera

Sutton ushers in modern photography with a new camera

The modern era of photography began in 1861 with the invention and patenting the world's first single is t lens reflex camera (SLR) camera by photography expert Tomas Sutton (1829-1875). His prototype led to the creation of the first batch of SLR cameras in 1884, with a design that is still in use today. Sutton also assisted jams Clerk Maxwell in his successful demonstration of color photography in 1861.
       In non-SLR cameras, light enters the viewfinder at a slightly different angle to that at which it enters the lens, so the resulting photo can appear different to intended composition. In SLR cameras, a mirror is positioned in front of the lens 
and directs light up into a pentaprism. The light bounces between its edges until enters the viewfinder with correct orientation, as if the viewer is looking directly through the camera  lens. When a photograph is taken, the mirror moves out of yhe way allowing liht to reach the flim or, with digital SLRs (DSLRs), the imagining sensors.
      Now the most popular professional camera format, the SLR camera was the culmination of decades of photographic innovations that began with the production of Louis Daguerre's  daguerrotype and Joes Maximilian Petzval's lens system, which le dto the first mass-produced cameras.
     Although no record of the first production model exists, the camera was first commercially produced in the mid-1800s. By the 1930s it was extremely popular with photographers, allowing and undistorted view od the subject from the correct perspective. DLSRs have all but replaced the traditional SLR, but the principle that Sutton pioneered is still used today.


With the decreasing costs, single-lens reflex cameras like this 1911 Adam's Minex became more popular. 

Hydraulic Jack (1851)

Dudgeon exploits water for heavy lifting

Hydraulic means moved or operated by water or liquid and refers to am method of engineering that has been used since records began. The ancient Chinese and Egyptians used water as a method of transport and the Romans relieved  heavily on it to move weighty objects. The arrival of the hydraulic jack in 1851, therefore, was not especially novel, but it was extremely useful.
         Essentially, a jack is a device that is capable of lifting heavy objects with relative ease. Hydraulic jacks make use of Pascal's Law that, in simple terms says that if there is an increase in pressure at any point in a container there of liquid, there is an equal increase in pressure at every other point within the container.
           Richard Dudgeon, Inc., was founded as a machine shop in New York in the mid-1800s, and its owner, finder, and namesake Richard Dudgeon was given a patent in 1851 for hydraulic jack- or, as he called it a "portable hydraulic press". Dudgeon also takes credit for several other mechanical inventions, including roller boiler tube expanders, filter press jacks, pulling jacks, heavy plate hydraulic hole punches, and various other kinds of lifting jacks.
           Dudgeon's hydraulic jack was vastly superior to the other jacks available at the time because of its seemingly infinite power. Compared with conventional screw jacks—which rely on a large hand-turned lead they are far easier to operate and offer a smother and more powerful lifting mechanism. The hydraulic jack was capable of easily lifting cars and other heavy machinery, which made it incredibly useful—and the device remains widely in use today