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London sinks were originally shallower than Belfast sinks. [5] (One plumbing guide in 1921 suggested that the Belfast sink was 38 centimetres (15 in) deep.) [7] Some believe this was because London had less access to fresh water (and thus a greater need to conserve water), but this theory is now contested. It is more likely the two sinks had ...
Ancient stone tools from Ethiopia were hand-crafted by Australopithecus or related people. [1] [2] [further explanation needed] 2.3 Mya: Earliest likely control of fire and cooking, by Homo habilis [3] [4] [5] 1.76 Mya: Advanced stone tools in Kenya by Homo erectus [6] [7] 1.75 Mya – 150 kya: Varying estimates for the origin of language [8] [9]
At first, the heavier solids were channeled into ditches on the side of the farm and were covered over when full, but soon flat-bottomed tanks were employed as reservoirs for the sewage; the earliest patent was taken out by William Higgs in 1846 for "tanks or reservoirs in which the contents of sewers and drains from cities, towns and villages ...
By 1965, around 75% of U.S. breweries were using them, but in the mid-1970s, pressure from environmentalists due to litter led to the development of the non-removable tabs used today. By 1980, his company was supplying can-end machinery worldwide making over $500 million in annual revenue.
Although Jefferson's investigative methods were ahead of his time, they were primitive by today's standards. The Egyptian Expedition under the Orders of Bonaparte , painting by Léon Cogniet Napoleon 's army carried out excavations during its Egyptian campaign , in 1798–1801, which also was the first major overseas archaeological expedition.
Silver, copper, tin and meteoric iron can also be found native, allowing a limited amount of metalworking in ancient cultures. [7] Egyptian weapons made from meteoric iron in about 3000 BC were highly prized as "daggers from Heaven". [8]
During the Fourth International Conference of Electricians in Chicago, electrical units were defined 1893: English physicist J. J. Thomson invented waveguides. 1894: Italian inventor Guglielmo Marconi begins developing the first radio wave based wireless telegraphy communication system [6] [7] 1895
The period when clocks were controlled by harmonic oscillators was the most productive era in timekeeping. [102] [note 7] The first invention of this type was the pendulum clock, which was designed and built by Dutch polymath Christiaan Huygens in 1656. Early versions erred by less than one minute per day, and later ones only by 10 seconds ...