Burglar alarms like this one are designed to alert the user to danger. Sensors are connected to a control unit through a low voltage wiring that interacts with a response device.

Burglar Detention Alarm

Burglar alarms like this one are designed to alert the user to danger. Sensors are connected to a control…

The process of physically assembling a book from a number of folded or unfolded sheets of paper or other material. It usually involves attaching covers to the resulting text-block.

Book Binding

The process of physically assembling a book from a number of folded or unfolded sheets of paper or other…

A breastplate is a device worn over the torso either to protect the torso from injury, or as an item of religious significance, or as an item of status.

Breastplate

A breastplate is a device worn over the torso either to protect the torso from injury, or as an item…

Armed robbery is less likely to happen than burglary, but it is a more dangerous threat to you, your employees, and your customers. Robbers choose targets that have cash readily available, accessible, and have loose security procedures. Even with the best precautions, robberies still occur

Device for Protection Against Robbers

Armed robbery is less likely to happen than burglary, but it is a more dangerous threat to you, your…

An illustration of a draw bridge.

Draw Bridge

An illustration of a draw bridge.

A funnel-shaped piece of brass is placed over the ends of a galvanometer when the resistance is equal to that of the pile. This acts as a preservative for the junctions from the heat radiated by the surrounding objects.

Funnel-shaped Brass

A funnel-shaped piece of brass is placed over the ends of a galvanometer when the resistance is equal…

"Fuse protection on instrument circuit of an alternating-current switchboard." —Croft 1920

Fuse Protection on Alternating Current Switchboard

"Fuse protection on instrument circuit of an alternating-current switchboard." —Croft 1920

"Illustrating fuse protection for voltmeter and ground detector and ground detector on a direct-current switchboard." —Croft 1920

Fuse Protection on Direct Current Swtichboard

"Illustrating fuse protection for voltmeter and ground detector and ground detector on a direct-current…

A gabion is an open cylinder made of brushwood, canvas, wire-netting, or iron bands used in fortification. Filled with loose earth, gabions are placed on end, in tiers, to form a wall behind which earth can be piled. They are usually constructed on location and made up of whatever materials are on hand.

Gabion

A gabion is an open cylinder made of brushwood, canvas, wire-netting, or iron bands used in fortification.…

A man standing in an armored lookout.

An Armored Lookout

A man standing in an armored lookout.

An illustration of a mortar and mount.

Mortar & Mount

An illustration of a mortar and mount.

Protective covering that protects something from direct sunlight.

Shade Roller

Protective covering that protects something from direct sunlight.

Screen to keep insects from entering a building through the open window

Window Screen

Screen to keep insects from entering a building through the open window

Screen to keep insects from entering a building through the open window

Window Screen

Screen to keep insects from entering a building through the open window

Lampshades are a fixture that covers the lightbulb on a lamp to diffuse the light it emits. Conical, cylindrical and other forms on floor-, desk- or table top-mounted as well as suspended lamp models are the most common and are made in a wide range of materials.

Lamp Shade

Lampshades are a fixture that covers the lightbulb on a lamp to diffuse the light it emits. Conical,…

An illustration of a group of slaves fleeing from Army.

Slaves Fleeing from Army

An illustration of a group of slaves fleeing from Army.

An illustration of a black umbrella with a curved handle.

Black Umbrella with Curved Handle

An illustration of a black umbrella with a curved handle.