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With the help of Charles Stearn, an expert on vacuum pumps, in 1878, Swan developed a method of processing that avoided the early bulb blackening. This received a British Patent in 1880.[dubious discuss] On 18 December 1878, a lamp using a slender carbon rod was shown at a meeting of the Newcastle Chemical Society, and Swan gave a working demonstration at their meeting on 17 January 1879. It was also shown to 700 who attended a meeting of the Literary and Philosophical Society of Newcastle upon Tyne on 3 February 1879. These lamps used a carbon rod from an arc lamp rather than a slender filament. Thus they had low resistance and required very large conductors to supply the necessary current, so they were not commercially practical, although they did furnish a demonstration of the possibilities of incandescent lighting with relatively high vacuum, a carbon conductor, and platinum lead-in wires. Besides requiring too much current for a central station electric system to be practical, they had a very short lifetime. Swan turned his attention to producing a better carbon filament and the means of attaching its ends. He devised a method of treating cotton to produce 'parchmentised thread' and obtained British Patent 4933 in 1880. From this year he began installing light bulbs in homes and landmarks in England. His house was the first in the world to be lit by a lightbulb and also the first house in the world to be lit by hydroelectric power. In 1878 the home of Lord Armstrong at Cragside was also among the first houses to be lit by electricity. In the early 1880s he had started his company. In 1881, the Savoy Theatre in the City of Westminster, London was lit by Swan incandescent lightbulbs, which was the first theatre, and the first public building in the world, to be lit entirely by electricity.

Why was Swan's first lamp not commercially viable?
Answer: 'parchmentised thread'
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In classical physics, an inertial reference frame is one in which an object that experiences no forces does not accelerate. In general relativity, an inertial frame of reference is one that is following a geodesic of space-time. An object that moves against a geodesic experiences a force. An object in free fall does not experience a force, because it is following a geodesic. An object standing on the earth, however, will experience a force, as it is being held against the geodesic by the surface of the planet. In light of this, the bucket of water rotating in empty space will experience a force because it rotates with respect to the geodesic. The water will become concave, not because it is rotating with respect to the distant stars, but because it is rotating with respect to the geodesic.

What follows a geodesic of space-time?
Answer: an inertial frame of reference
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For over 200 years, Russia had been expanding southwards across the sparsely populated "Wild Fields" toward the warm water ports of the Black Sea that did not freeze over like the handful of other ports available in the north. The goal was to promote year-round trade and a year-round navy.:11 Pursuit of this goal brought the emerging Russian state into conflict with the Ukrainian Cossacks and then with the Tatars of the Crimean Khanate and Circassians. When Russia conquered these groups and gained possession of southern Ukraine, known as New Russia during Russian imperial times, the Ottoman Empire lost its buffer zone against Russian expansion, and Russia and the Ottoman Empire fell into direct conflict. The conflict with the Ottoman Empire also presented a religious issue of importance, as Russia saw itself as the protector of Orthodox Christians, many of whom lived under Ottoman control and were treated as second-class citizens.(ch 1)

For 200 years, Russia been expanding across what area?
Answer:
Wild Fields