The Standard Electrical Dictionary Part 147

Static Breeze.

The electric breeze obtained by the silent discharge of high tension electricity.

Static Electricity.

Electricity at rest or not in the current form ordinarily speaking. The term is not very definite and at any rate only expresses a difference in degree, not in kind. The recognition of the difference in degree has now to a great extent also disappeared.

Station, Central.

The building or place in which are placed electrical apparatus, steam engines and plant supplying a district with electric energy.

Station, Distant.

The place at the further end of a telegraph line, as referred to the home station.

Station, Home.

The end of a telegraph line where the operators using the expression are working.

494 STANDARD ELECTRICAL DICTIONARY.

Station, Transforming.

In alternating current distribution, a building or place where a number of transformers are worked, so that low potential or secondary circuits are distributed therefrom.

Steel.

A compound of iron with carbon. The carbon may range from a few hundredths of one per cent. up to two per cent. For magnets, tool steel drawn to a straw color or a little lower is good. All shaping and filing should be done before magnetization.

Steeling.

The deposition of iron on copper plates by electrolysis. In electrotyping a thin deposit of iron is thus given the relief plates before printing from them. The deposit is very hard and exceedingly thin, so that it does not interfere with the perfection of the impression in the printing process. As the iron becomes worn it can be dissolved off with hydrochloric acid, which does not dissolve the copper, and a new deposit can be given it. Thus the plate may last for an indefinite number of impressions.

The iron bath may be prepared by immersing in a solution of ammonium chloride, two plates of iron, connected as anode and kathode in a circuit. One plate dissolves while hydrogen is given off from the other.

The solution thus produced is used for a bath.

The hardness of the deposit, which is really pure iron, gives the name of "steeling."

Synonym--Acierage.

St. Elmo's Fire.

Luminous static discharge effects sometimes seen on objects elevated in the air. They are especially noticed on s.h.i.+ps' masts. The sailors term them corpusants (holy bodies). They resemble tongues or globes of fire.

Step-by-step Telegraphy.

A system of telegraphy in which in the receiving instrument a hand is made to move step-by-step, with an escape movement around a dial. For each step there is a letter and the hand is made to stop at one or the other letter until the message is spelled out. (See Dial Telegraph.)

Step-down. adj.

A qualification applied to a converter or transformer in the alternating current distribution, indicating that it lowers potential difference and increases current from the secondary.

Step-up. adj.

The reverse of step-down; a qualification of a transformer or converter indicating that it raises the potential and decreases the current in the secondary.

Sticking.

The adherence, after the current is cut off, of the armature to the poles of a magnet. In telegraphy it is a cause of annoyance and obstructs the working. It may, in telegraphy, be due to too weak a spring for drawing back the armature, or to imperfect breaking of the contact by the despatcher's key or by the receiver's relay.

495 STANDARD ELECTRICAL DICTIONARY.

Stopping Off.

In electroplating the prevention of deposition of the plating metal on any desired portions of the object. It is effected by varnis.h.i.+ng the places where no coating is desired. An article can be plated with silver, stopped off in any desired design, and the unvarnished portions may then be plated with gold in another bath. Various effects can be produced by such means.

Storage Capacity.

A term for the ampere-hours of electricity, which can be taken in current form from a storage battery.

Storage of Electricity.

Properly speaking electricity can only be stored statically or in static condensers, such as Leyden jars. The term has been popularly applied to the charging of secondary or storage batteries, in which there is really no such thing as a storage of electricity, but only a decomposition and opposite combination brought about, which leave the battery in a condition to give a current.

Storms, Electric.

Wide-spread magnetic and electric disturbances, involving the disturbance of the magnetic elements and other similar phenomena. (See Magnetic Storms.)

Strain.

The condition of a body when subjected to a stress. Various consequences may ensue from strain in the way of disturbance of electric and other qualities of the body strained.

Stratification Tube.

A Geissler tube, q. v., for showing the stratification of the electric discharge through a high vacuum.

The stratifications are greatly intensified by the presence of a little vapor of turpentine, alcohol, bisulphide of carbon and other substances.

Stray Field.

In a dynamo or motor the portion of the field whose lines of force are not cut by the armature windings.

Stray Power.

The proportion of the energy wasted in driving a dynamo, lost through friction and other hurtful resistances.