PIMPERNEL (Anagallis arvensis), a small herb of the prim rose family (Primulaceae), called also shepherd's clock and poor man's weather-glass, native to Europe and widely naturalized in North America from Newfoundland to the Pacific coast and southward to Mexico. It is a delicate annual with diffusely branching stems, with small, opposite, somewhat clasping, leaves, black-dotted beneath, and scarlet (rarely white) flowers, about -1 in. across, usually with a darker centre, opening only in bright sunshine, whence numerous popular names.
a small peg or bolt of metal or wood, not necessarily pointed, employed as a fastening to connect together different parts of an article, as a stop to limit the motion of some moving piece in a machine, as a support on which a small wheel may turn, etc., but most commonly a small metal spike, used for fastening portions of fabrics together, having one end pointed and at the other a bulbed head, or some other arrangement for preventing the spike from passing entirely through the cloth or other material with which it is employed. In one form or another pins of this last kind are of the highest antiquity, the earliest form doubtless being a natural thorn. Pins of bronze, and bronze brooches in which the pin is the essential feature, are of common occurrence among the remains of the bronze age. The ordinary domestic pin had become in the 15th century an article of sufficient importance in England to warrant legislative notice, as in 1483 the importation of pins was prohibited by statute. In 154o Queen Catherine received pins from France, and again in 1543 an act was passed providing that "no person shall put to sale any pinnes but only such as shall be double headed, and have the heads soldered fast to the shank of the pinnes, well smoothed, the shank well shapen, the points well and round filed, canted and sharpened." At that time pins of good quality were made of brass ; but a large proportion of those against which the legislative enactment was directed were made of iron wire blanched and passed as brass pins. To a large extent the sup ply of pins in England was received from France till about 1626, in which year the manufacture was introduced into Gloucestershire by John Tilsby. In 1636 the pinmakers of London formed a corpo ration, and the manufacture was subsequently established at Bris tol and Birmingham, the latter town ultimately becoming the prin cipal centre of the industry. So early as 1775 the attention of the
enterprising colonists in Carolina was drawn to the manufacture by the offer of prizes for the first native-made pins and needles. At a later date several pin-making machines were invented in the United States. During the War of
when the price of pins rose enormously, the manufacture was actually started, but the indus try was not fairly successful till about the year 1836 when the Howe Manufacturing company was formed at Birmingham, Con necticut. Previous to this an American, Lemuel W. Wright, had in 1824 secured in England a patent for a machine to make solid headed pins, which established the industry on its present basis.
In a modern pin-making machine wire of suitable gauge running off a reel is drawn in and straight ened by passing between straightening pins or studs set in a table. When a pin length has entered it is caught by lateral jaws, be yond which enough of the end projects to form a pin-head. Against this end a steel punch advances and compresses the metal by a die arrangement into the form of a head. The pin length is im mediately cut off and the headed piece drops into a slit sufficient ly wide to pass the wire through but retain the head. The pins are consequently suspended by the head while their projecting extremities are held against a revolving cutter, by which they are pointed.
Then follows the finishing process, which consists of giving the pins the coating of tin which makes them silvery in appearance. In the case of brass pins, they are scoured, cleaned in argol (bitartrate of potash) and water and then tinned in a vat in a solution of water, oxalic acid and granulated tin mixed with the pins at a temperature of 00°C. Iron pins are tinned by an electrolytic process in an alkaline solution of a tin salt. After be ing washed and dried the pins are polished by being revolved in a barrel, mixed with dry bran or fine sawdust, from which they are winnowed as finished pins. The sizes of ordinary pins range from the 31-in. stout blanket pin down to the finest slender gilt pin used by entomologists, 4,500 of which weigh about an ounce.