The Seismoscope Is One of the Great Chinese Inventions

The Seismoscope Is One of the Great Chinese Inventions There are few things more disconcerting than the sensation of the seemingly-solid Earth suddenly rolling and pitching beneath ones feet. As a result, humans have sought ways to measure or even predict earthquakes for thousands of years. Although we still cant accurately predict earthquakes, humans have come a long way in detecting, recording, and measuring seismic shocks. This process began nearly 2000 years ago, with the invention of the first seismoscope in China. The First Seismoscope In 132 CE, inventor, Imperial Historian, and Royal Astronomer Zhang Heng displayed his amazing earthquake-detection machine, or seismoscope, at the court of the Han Dynasty. Zhangs seismoscope was a giant bronze vessel, resembling a barrel almost 6 feet in diameter. Eight dragons snaked face-down along the outside of the barrel, marking the primary compass directions. In each dragons mouth was a small bronze ball. Beneath the dragons sat eight bronze toads, with their broad mouths gaping to receive the balls. We dont know exactly what the first seismoscope looked like. Descriptions from the time give us an idea about the size of the instrument and the mechanisms that made it work. Some sources also note that the outside of the seismoscopes body was beautifully engraved with mountains, birds, tortoises, and other animals, but the original source of this information is difficult to trace. The exact mechanism that caused a ball to drop in the event of an earthquake also is not known. One theory is that a thin stick was set loosely down the center of the barrel. An earthquake would cause the stick to topple over in the direction of the seismic shock, triggering one of the dragons to open its mouth and release the bronze ball. Another theory posits that a baton was suspended from the lid of the instrument as a free-swinging pendulum. When the pendulum swung widely enough to strike the side of the barrel, it would cause the closest dragon to release its ball. The sound of the ball striking the toads mouth would alert observers to the earthquake. This would give a rough indication of the earthquakes direction of origin, but it did not provide any information about the intensity of the tremors. Proof of Concept Zhangs wonderful machine was called houfeng didong yi, meaning an instrument for measuring the winds and the movements of the Earth. In earthquake-prone China, this was an important invention.   In one instance, just six years after the device was invented, a large quake estimated at a magnitude seven struck what is now Gansu Province. People in the Han Dynastys capital city of Luoyang, 1,000 miles away, did not feel the shock. However, the seismoscope alerted the emperors government to the fact that a quake had struck somewhere to the west. This is the first known instance of scientific equipment detecting an earthquake that had not been felt by humans in the area. The seismoscopes findings were confirmed several days later when messengers arrived in Luoyang to report a major earthquake in Gansu. ChineseSeismoscopes on the Silk Road? Chinese records indicate that other inventors and tinkerers in the court improved upon Zhang Hengs design for the seismoscope over the centuries that followed. The idea seems to have spread westward across Asia, probably carried along the Silk Road.   By the 13th century, a similar seismoscope was in use in Persia, although the historical record does not provide a clear link between the Chinese and Persian devices. It is possible that the great thinkers of Persia hit upon a similar idea independently.

Learn to Spell by Phonograms, not Letters

Learn to Spell by Phonograms, not Letters Learn to Spell by Phonograms, not Letters Learn to Spell by Phonograms, not Letters By Maeve Maddox In the 1970s, educational research indicated that less than one per cent of the population suffered what has come to be called dyslexia (a disturbance of the ability to read). Now the estimate is from 5 to 15 per cent. As early as 1955 Rudolf Flesch pointed out the disconnect between modern teaching methods and the ability to read (or spell) in Why Johnny Cant Read and What You Can Do About It. After half a century, Fleschs book remains a thorn in the side of the advocates of the sight method of teaching children to read. Parents of young children would do well to read it. I once tutored a child who looked at the word April and read it as May. He knew that the word represented the name of a month because hed been taught the names of the months in context. He apparently did not know how to decipher it by its spelling. Adult readers recognize words by sight. Experienced readers can recognize words if only some of the letters are showing. They can recognize them if the words are upside down. This ability comes from having seen the words hundreds or thousands of times. Beginning readers, however, need systematic instruction in approaching words from left to right, phonogram by phonogram. To develop confidence and fluency in readingand the ability to spellthey need to begin with words like hat, cot, and bin before encountering words like know, they, or eight. (The latter three words are on the Dolch List taught to beginning readers with the use of flashcards.) NOTE: The use of flashcards to develop instant word recognition is a useful techniquebut only after the beginning reader has been taught the phonetic elements of the word being drilled. Its counterproductive to expose a beginner who knows only the 26 letters of the alphabet to words spelled with sounds represented by letter combinations like th, kn, ay, igh, and eigh. Relatively few of the common words on the Dolch List defy the effort to sound them out by their phonograms. Those few, like once and warm, are easily taught as exceptions. The most efficient way to learn to spell a word is to approach it phonogram by phonogram, and not letter by letter. A phonogram is a written symbol that stands for a sound. The word pal, for example, contains three letters, each of which is also a phonogram: /p-a-l/. The word church , on the other hand, contains six letters, but only three phonograms: /ch-ur-ch/. Here are some phonograms to look for when analyzing a words spelling: Consonant phonograms: b, c, d, f, g, h, j, k, l, m, n, p, r, s, t, v, w, x, y, z, sh, th, ch, ng, ck, wh, kn, gn, wr, ph, dge, gh, ti, si, ci, pn, rh, and qu. Vowel (and semi-vowel) phonograms: a, e, i, o, u, y, ee, ay, ai, ow, ou, oy, oi, aw, au, ew, ui, oo, ea, ar, er, ir, ur, or, ed, or, oa, ey, ei, ie, igh, eigh, oe, ough, and eu. Want to improve your English in five minutes a day? Get a subscription and start receiving our writing tips and exercises daily! Keep learning! Browse the Spelling category, check our popular posts, or choose a related post below:The Meaning of "To a T"Time Words: Era, Epoch, and EonAppropriate vs. Apropos vs. Apt