What is an Electro-Magnet?
An electro-magnet is a piece of iron temporarily converted into a magnet by means of a current of electricity sent through a wire which is coiled around it. The wire is usually covered with silk, cotton, gutta percha or some other insulator, to prevent the current from leaping across, and compel it to travel through the whole length of the wire.
The more pure and soft the iron is, the stronger will its magnetism be while it lasts, and the more completely will it disappear when the current stops. Steel is less affected than soft iron for the time, but remains permanently magnetized after the current ceases. Electro-magnets are usually much more powerful than other magnets of the same size.
The iron which is magnetized by the current passing around it is called the core. It is frequently straight, the wire being wound upon it like thread upon a reel; but very frequently it has the shape of a U or horseshoe, the wire being coiled round the two ends and the bend of the U left uncovered.
The Story in a Pin[25]
A pin, so common and so cheap today, was once so expensive that only the wealthy could afford even a few. The term pin-money dates from that time and originally came from the allowance a husband gave his wife to purchase pins.
From an historical point of view, it appears that the need of something with which to fasten together pieces of cloth and like material has been met from ancient times by various devices. Among the remains of the bronze age are found pins and brooches of bronze. In Egyptian tombs have been found elaborate and costly pins, which range in sizes from two inches to seven or eight inches long, and have large gold heads or bands of gold around the upper end. Designs were often worked on these heads and bands. The largest of these pins were probably used for fastening the hair. Till the middle of the sixteenth century the poorer class in England used rude skewers of wood, while the more fortunate had pins made of gold, silver and brass. The Indians, in the ancient cities of Mexico, satisfied their need for pins by using the thorn of the agave.
As early as 1483, pins were important enough in England to warrant the passing of a law by Parliament prohibiting their importation. By 1540, however, they were being imported in large quantities from France. Parliament again passed a law regarding pins in 1543. This act provided that “no person shall put to sale any pins, but only such as shall be double-headed, and have the heads soldered fast to the shank of the pin, well smoothed, and shanks well shapen, the points well round filed, canted, and sharpened.” Some pins of good quality were made at this time, but a large portion of those against which the legislative enactment was directed were made of iron wire, blanched and passed for brass pins. Only three years after this prohibitory law was passed it became obsolete because of the improvements which had been made in the production of these articles. England continued to receive its supply from France until John Tilsby began their manufacture in Gloucestershire. His business increased to such an extent that in a few years he had 1,500 people in his employ. In 1636 the pinmakers of London formed a corporation and established the industry of Bristol and Birmingham. This latter city is still the center of the industry in England.
The First Pin is a Flat-headed Copper Pin Probably Used for Fastening Hair. The Second is a Star-headed Bronze Pin. Both are of the Types which have been Found Among the Remains of the Bronze Age. The Third Pin is a Handmade Pin of the Seventeenth Century
During this period the pins were made with two coils of wire fastened at one end of a length of wire, the other end of which was sharpened. First a wire, somewhat finer than that which was to be used for the pin, was coiled around a spit on a lathe. This was cut up into sections, each consisting of two turns. These coils were then annealed or softened and placed in a heap. Boys stuck the ends of the pins, which had been cut to the proper length, into this pile until a coil stuck. A workman pressed this coil in a die to make it hold to the pin. The head was then soldered and the other end of the pin filed and sharpened. Finally the pin was straightened and blanched or whitened.
In the United States the colonists early felt the need of local production. The colonial legislature of Carolina offered prizes in 1775 for the first native-made pins and needles. The first American pins were made in Rhode Island, during the Revolution, by Jeremiah Wilkinson. About the same time, Samuel Slocum made pins in Providence. These were handmade with twisted wire heads.
A View of the Pin Machine Room in a Modern Pinmaking Plant
There are many types of pin machines which make anywhere from ninety to three hundred pins a minute, depending on the quality of the pin made.
Pinmaking machines were first invented in the United States. During the War of 1812, the industry was started because of the difficulty of getting pins from England, where most of them were made. The industry was not successful, however, till 1836, when the Howe Manufacturing Company was formed at Birmingham, Conn. It is a curious coincident that the first successful American pin manufacturing company, making the new machine-made pins, should be established in the Connecticut town of the same name as the English city which had been the center of pinmaking for nearly two hundred years.
In 1817 a paper was filed at the patent office by Seth Hunt, describing a machine for making pins with “head, shaft, and point in one entire piece.” This machine, however, did not come into use. Lemuel W. Wright, of New Hampshire, secured, in 1824, an English patent for a machine for making solid-headed pins. This was the beginning of the present industry. A factory equipped with Wright’s machines was established in London, but was not successful. Daniel Foot-Taylen, of Birmingham, purchased this equipment and secured an extension of Wright’s patents for five years from 1838. He carried the production of machine-made pins to a commercial basis. Wright’s machines, however, did not complete all operations. Dr. John Neland Howe, a physician of Bellevue Hospital, New York City, formed a company in 1832 for the manufacture of pins. This concern was not successful, but in 1835 a second company was formed by Dr. Howe, who had great faith in the future of the industry. Nine years later, Samuel Slocum, of Connecticut, invented a new machine for sticking the pins on papers.
The Whitening Room, where the Pins are Cleaned and Plated
In the tumbling barrels the pins are cleaned and dried by tumbling in sawdust which has been heated in the ovens in the center background.
Since that time there have been many pin machines developed, each accomplishing the same result in slightly different ways. In each case a special stiff pin wire is drawn into the machine from a large hank, which is placed on a drum on the machine. The wire is first passed through a series of rapidly revolving, straightening rolls which take out all twists and kinks. The proper length of wire is fed into the machine automatically, and the end is gripped by a set of jaws. A small part of the end of the wire extends beyond the jaws. This is struck several rapid blows by a die called the header. After the head is thus formed, the wire is cut off to the proper length and is then ready to be pointed. It is now carried along by a shaft having a screw thread, and is made to revolve rapidly by a belt which passes over it. The end to be pointed passes over a series of coarse, medium and fine revolving files or cutters. The pin now drops into a pan, ready to be finished after being inspected.
In the finishing room, the pins are put into a revolving or tumbling barrel and are rolled in sawdust, which absorbs all the oil, leaving them clean and bright. They are now dropped through a blower, where the sawdust is separated from the pins. The whitening is done by boiling the pins in a large copper kettle, which also contains layers of grained tin and a solution of argol or bitartrate of potash. After boiling for five or six hours, they have a thin coating of tin, which gives them their silvery appearance. Again they are cleaned, this time being washed in clean water, then tumbled in strong soap water, and finally tumbled in hot sawdust to dry them. The pins are separated from the sawdust as before. From there the pins go to the sticking department, where they are stuck on papers as you buy them. The sticking machine is of a simple construction, but is wonderful in operation, and requires no attention by the operator, except to keep it supplied with pins and papers.
The pins are put into a vibrating hopper, which slopes slightly towards the sticking machine. The conductor from the hopper to the machine is made of two strips of steel, down which the pins, held by their heads, slide. They are taken from the conductor by a screw thread and fed to the carrier, which takes thirty pins at a time and places them in front of a set of thirty punches. They are then forced along thirty grooves in the steel clamps, which crimp the paper, and on through the crimp. Thus a whole row of pins is stuck at once. The paper is now advanced the proper distance, and another row is stuck. When the center of the paper is reached, after six rows have been stuck, the machine automatically spaces the paper so as to skip the space used for the brand name. Then six more rows are stuck, and the operator removes the completed paper and inserts another without stopping the machine. These papers are inspected to make certain that no poorly made pins have gotten by the former inspection, are rolled and packed, usually in boxes of twelve papers each.
Pins today are made in many sizes from the 31⁄2-inch stout blanket pins down to the fine, slender, bronze pins used by entomologists, 4,500 of which pins make an ounce. Toilet pins are usually made in six sizes as shown in the [illustrations]. Besides the common or toilet pins, there are today numerous special bank and desk pins which are made to meet special requirements.
Pin production in the United States has reached a high stage of development. The number of pins made in 1914 reached the tremendous total of 25,000,000,000. These figures are almost too great for comprehension. If all the pin wire used for these 25,000,000,000 pins were in one piece it would go around the earth fifteen times. Safety pins, hooks and eyes, and hairpins, are generally made by pin concerns. Each of these different articles require very ingenious machines. Many of them are almost human in their operation.
The popular name of the prominence seen in the front of the throat in a man is called the “Adam’s apple” because of the story in the Old Testament, telling of the eating of the forbidden fruit of the tree of knowledge by Adam, a piece being supposed to have lodged in his throat where the bulge appears.
An Alpine Glacier
The Mer de Glace
The upper view shows the method of crossing a glacier. Each of the climbers is carrying an alpenstock, or staff with ice ax at one end and spike at the other. The lower view is the famous sea of ice in Switzerland.
Mount Rainier, Washington
One of the largest glacial systems in the world radiating from a single peak is situated on this mountain in western Washington.