The arquebus, derived from the German word Hakenbüchse, was a form of long gun that appeared in Europe and the Ottoman Empire during the 15th century. Although the term arquebus was applied to many different forms of firearms from the 15th to 17th centuries, it referred to "a hand-gun with a hook-like projection or lug on its under surface, useful for steadying it against battlements or other objects when firing"; these "hook guns" were in their earliest forms defensive weapons mounted on German city walls in the early 1400s. The addition of a shoulder stock, priming pan, matchlock mechanism in the late 15th century turned the arquebus into a handheld firearm and the first firearm equipped with a trigger; the exact dating of the matchlock's appearance is disputed. It could have appeared in the Ottoman Empire as early as 1465 and in Europe a little before 1475; the heavy arquebus, known as the musket, was developed to better penetrate plate armor and appeared in Europe around 1521. A standardized arquebus, the caliver, was introduced in the latter half of the 16th century.

The name "caliver" is derived from the English corruption of calibre, a reference to the gun's standardized bore. The caliver allowed troops to load bullets faster since they fit their guns more whereas before soldiers had to modify their bullets into suitable fits, or were forced to make their own prior to battle; the smoothbore matchlock arquebus is considered the forerunner to the rifle and other long gun firearms. Heavy arquebuses mounted on wagons were called arquebus à croc; these carried a lead ball of about 3.5 ounces. An infantryman armed with an arquebus is called an arquebusier; the arquebus has at times been known as the harquebus, hackbut, archibugio, schiopo, sclopus, tüfenk, tofak and firelock. In the early 16th century, the term "arquebus" was used to describe an assortment of guns, but by the late 16th century the arquebus and musket had settled down into size categories for firearms. Continental European powers such as the Spanish and French differentiated muskets from arquebuses by size and if they required a fork rest or not.

However, the musket—essentially a large arquebus—which had been introduced around 1521, fell out of favor in the mid-16th century due to the decline of armor, but the term stuck around and musket became a generic descriptor for all'shoulder arms' fireweapons into the 1800s. At least on one occasion the musket and arquebus have been used interchangeably to refer to the same weapon, referred to as an "arquebus musket". A Habsburg commander in the mid-1560s once referred to muskets as "double arquebuses"; the matchlock firing mechanism became a common term for the arquebus after it was added to the firearm. Flintlock firearms were sometimes called fusils or fuzees. Prior to the appearance of the serpentine lever by around 1411, handguns were fired from the chest, tucked under one arm, while the other arm maneuvered a hot pricker to the touch hole to ignite the gunpowder; the matchlock which appeared around 1475 changed this by adding a firing mechanism consisting of two parts, the match, the lock.

The lock mechanism held within a clamp a two to three feet long length of smoldering rope soaked in saltpeter, the match. Connected to the lock lever was a trigger, which lowered the match into a priming pan when squeezed, igniting the priming powder, causing a flash to travel through the touch hole igniting the gunpowder within the barrel, propelling the bullet out the muzzle; the trigger mechanism of the early arquebus most resembled that of a crossbow: a curved lever pointing backward and parallel to the stock. By the 16th century, gunsmiths in most countries had begun to introduce the short trigger perpendicular to the stock, familiar to modern shooters. However, the majority of French matchlock arquebuses retained the crossbow-style trigger throughout the 17th century. While matchlocks provided a crucial advantage by allowing the user to aim the firearm using both hands, it was awkward to utilize. To avoid accidentally igniting the gunpowder the match had to be detached while loading the gun.

In some instances the match would go out, so both ends of the match were kept lit. This proved cumbersome to maneuver as both hands were required to hold the match during removal, one end in each hand; the procedure was so complex that a 1607 drill manual published by Jacob de Gheyn in the Netherlands listed 28 steps just to fire and load the gun. In 1584 the Ming general Qi Jiguang composed an 11-step song to practice the procedure in rhythm: "One, clean the gun. Two, pour the powder. Three, tamp the powder down. Four, drop the pellet. Five, drive the pellet down. Six, put in paper. Seven, drive the paper down. Eight, open the flashpan cover. Nine, pour in the flash powder. Ten, close the flashpan, clamp the fuse. Eleven, listen for the signal open the flashpan cover. Aiming at the enemy, raise your gun and fire." Reloading a gun during the 16th century took anywhere from 20 seconds to a minute under the most ideal conditions. The development of volley fire—by the Ottomans, the Chinese, the Japanese, the Dutch—made the arquebus more feasible for widespread adoption by the military.

The volley fire technique transformed soldiers carrying firearms into organized firing squads with each row of soldiers firing in turn and reloading in a systematic fashion. Volley fire was implemented with cannons as early as 1388 by Ming artillerists, but volley fire with matchlocks was not implemented until 1526 when the Ottoman Janissaries utilized it during the Battle of Mohács; the matchloc

O. P. Ramaswamy Reddiyar

Omandur Ramasamy Reddiyar was an Indian freedom-fighter and politician of the Indian National Congress. He served as the Premier of Madras Presidency from 23 March 1947 to 6 April 1949.. Omandur Ramaswamy Reddy was born in 1 February 1895 in the village of Omandur near Tindivanam in the South Arcot district of Madras Presidency, he belonged to a Reddiar family. He had his schooling at Walter Scudder school and entered the Indian independence movement at an early age. Ramaswamy Reddy was a devotee of Vallalar. Ramaswamy Reddy became the Chief Minister or Premier of Madras on 23 March 1947 and was in power till 6 April 1949. During his tenure, the Madras Temple Entry Authorization Act 1947 was passed; this act was intended to give Dalits and other prohibited Hindus full and complete rights to enter Hindu temples. This was approved by the Governor on 11 May 1947 and passed as Madras Act 5 of 1947; the Devadasi Dedication Abolition Act of 1947 put an end to the devadasi system, in vogue in many Hindu temples.

It was during Reddy's tenure. Soon after independence and partition of India, there was a shortage of food grains rice, in the province. In 1948, Reddy ordered the purchase of a de Havilland Dove, the first aeroplane to be owned by the Government of Madras. In 1948, when the Congress legislative party elections were held, Reddy's candidature was opposed by Tanguturi Prakasam. However, Reddy won with the support of K. Kamaraj. However, the Congress leaders were disgruntled with Reddy as he did not allow them special privileges. So, during the 1949 Congress Legislative Party elections, Kamaraj supported P. S. Kumaraswamy Raja against Reddy. Though Reddy was supported by C. Rajagopalachari, P. Subbarayan and T. Prakasam, he stepped down as Chief Minister. ChangesSubbarayan resigned on 5 April 1948, Daniel Thomas on 15 June 1948 and Kala Venkata Rao on 24 January 1949; when his Premiership of Madras Presidency came to an end in April 1949, Reddy was elected to the Constituent Assembly of India. The complex of buildings that houses the Tamil Nadu Legislative Assembly has been named after him.

A commemorative postage stamp on him was released on 25 August 2010. O. P. Ramaswamy Reddy. Agrarian reforms and parity economy. Economic Adviser to the Government of Madras. O. P. Ramaswamy Reddy. Address delivered on the occasion of opening the 19th annual conference on Land Mortgage Banks held on 13th March 1949

Dimethylaminophosphorus dichloride

Dimethylaminophosphorus dichloride is an organophosphorus compound with the formula Me2NPCl2. A colorless liquid, it is a reagent in the preparation of other organophosphorus compounds. Many analogous compounds can be prepared from the reactions of secondary amines and phosphorus trichloride: 2 R2NH + PCl3 → R2NPCl2 + R2NH2Cl Further equivalents of amine react with dialkylaminophosphorus dichlorides: 2 R2NH + R2NPCl2 → 2PCl + R2NH2ClSince the P-NR2 bond is not attacked by Grignard reagents, dimethylaminophosphorus dichloride can be selectively dimethylated: 2 MeMgBr + Me2NPCl2 → Me2NPMe2 + 2 MgBrClThe resulting dimethylphosphino derivative, a structural relative of tetramethylhydrazine, reacts with hydrogen chloride to give chlorodimethylphosphine: Me2NPMe2 + 2 HCl → ClPMe2 + Me2NH2Cl