Dominies log
A.S. Neill's A Dominie's Log is a diary of his first year as headteacher at Gretna Green Village School, during 1914-15. It is an autobiographical novel. He changed a hard working, academic school controlled by corporal punishment and the fear of the authority of the teacher into one of happiness, play and children controlling their learning. He was a reflective teacher, sitting on his desk thinking out why he and the children were at the school. He also, most importantly thought the children were human beings, and engaged with them as such, joining in their games, sliding with them on an ice slide in the street, sharing their sweets, laughing with them, and appreciating and respecting their individuality, and creativity.
Celebrating the Practicing Teacher
Data logger
A data logger (also datalogger or data recorder) is an electronic device that records data over time or in relation to location either with a built in instrument or sensor or via external instruments and sensors. Increasingly, but not entirely, they are based on a digital processor (or computer). They generally are small, battery powered, portable, and equipped with a microprocessor, internal memory for data storage, and sensors. Some data loggers interface with a personal computer, and use software to activate the data logger and view and analyze the collected data, while others have a local interface device (keypad, LCD) and can be used as a stand-alone device.
Data loggers vary between general purpose types for a range of measurement applications to very specific devices for measuring in one environment or application type only. It is common for general purpose types to be programmable; however, many remain as static machines with only a limited number or no changeable parameters. Electronic data loggers have replaced chart recorders in many applications.
Logarithm
In mathematics, the logarithm is the inverse operation to exponentiation. That means the logarithm of a number is the exponent to which another fixed value, the base, must be raised to produce that number. In simple cases the logarithm counts repeated multiplication. For example, the base 10 logarithm of 1000 is 3, as 10 to the power 3 is 1000 (1000 = 10 × 10 × 10 = 103); the multiplication is repeated three times. More generally, exponentiation allows any positive real number to be raised to any real power, always producing a positive result, so the logarithm can be calculated for any two positive real numbers b and x where b is not equal to 1. The logarithm of x to base b, denoted logb(x), is the unique real number y such that
For example, as 64 = 26, we have
The logarithm to base 10 (that is b = 10) is called the common logarithm and has many applications in science and engineering. The natural logarithm has the number e (≈ 2.718) as its base; its use is widespread in mathematics and physics, because of its simpler derivative. The binary logarithm uses base 2 (that is b = 2) and is commonly used in computer science.
Chip log
A chip log, also called common log, ship log, or just log, is a navigation tool mariners use to estimate the speed of a vessel through water. The word knot, to mean nautical mile per hour, derives from this measurement method.
History
All nautical instruments that measure the speed of a ship through water are known as logs. This nomenclature dates back to the days of sail, when sailors tossed a log attached to a rope knotted at regular intervals off the stern of a ship. Sailors counted the number of knots that passed through their hands in a given time to determine the ship's speed. They had to know the speed to navigate using dead reckoning, which was usual practice before modern navigation instruments like GPS. Today, sailors and aircraft pilots still use the written term "knot[s]" to express speed, although the modern term is a respelling of "naut[s]," an abbreviation of "nautical mile[s]."
Construction
A chip log consists of a wooden board attached to a line (the log-line). The log-line has a number of knots at uniform intervals. The log-line is wound on a reel so the user can easily pay it out.
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