The horizontal alignment signs may be used in advance of situations where the horizontal roadway alignment changes. If the change in horizontal alignment is approximately 270 degrees, such as on a cloverleaf interchange ramp, the 270-degree Loop sign may be used.

270 Degree Loop, Black and White

The horizontal alignment signs may be used in advance of situations where the horizontal roadway alignment…

The horizontal alignment signs may be used in advance of situations where the horizontal roadway alignment changes. If the change in horizontal alignment is approximately 270 degrees, such as on a cloverleaf interchange ramp, the 270-degree Loop sign may be used.

270 Degree Loop, Color

The horizontal alignment signs may be used in advance of situations where the horizontal roadway alignment…

The horizontal alignment signs may be used in advance of situations where the horizontal roadway alignment changes. If the change in horizontal alignment is approximately 270 degrees, such as on a cloverleaf interchange ramp, the 270-degree Loop sign may be used.

270 Degree Loop, Outline

The horizontal alignment signs may be used in advance of situations where the horizontal roadway alignment…

The horizontal alignment signs may be used in advance of situations where the horizontal roadway alignment changes. If the change in horizontal alignment is approximately 270 degrees, such as on a cloverleaf interchange ramp, the 270-degree Loop sign may be used.

270 Degree Loop, Silhouette

The horizontal alignment signs may be used in advance of situations where the horizontal roadway alignment…

"Water enters the wheel halfway up and flows against the slots on the wheel. The wheel rotates with the flow of the water and the stream continues out the bottom of the wheel." —Quackenbos 1859

Breast Wheel

"Water enters the wheel halfway up and flows against the slots on the wheel. The wheel rotates with…

This is the command used to instruct the unit to change direction.

Change Direction

This is the command used to instruct the unit to change direction.

The horizontal alignment signs may be used in advance of situations where the horizontal roadway alignment changes. When the Hairpin Curve sign or the 270-degree Loop sign is installed, either a One-Direction Large Arrow sign or Chevron Alignment signs should be installed on the outside of the turn or curve.

Chevron Alignment, Black and White

The horizontal alignment signs may be used in advance of situations where the horizontal roadway alignment…

The horizontal alignment signs may be used in advance of situations where the horizontal roadway alignment changes. When the Hairpin Curve sign or the 270-degree Loop sign is installed, either a One-Direction Large Arrow sign or Chevron Alignment signs should be installed on the outside of the turn or curve.

Chevron Alignment, Color

The horizontal alignment signs may be used in advance of situations where the horizontal roadway alignment…

The horizontal alignment signs may be used in advance of situations where the horizontal roadway alignment changes. When the Hairpin Curve sign or the 270-degree Loop sign is installed, either a One-Direction Large Arrow sign or Chevron Alignment signs should be installed on the outside of the turn or curve.

Chevron Alignment, Outline

The horizontal alignment signs may be used in advance of situations where the horizontal roadway alignment…

The horizontal alignment signs may be used in advance of situations where the horizontal roadway alignment changes. When the Hairpin Curve sign or the 270-degree Loop sign is installed, either a One-Direction Large Arrow sign or Chevron Alignment signs should be installed on the outside of the turn or curve.

Chevron Alignment, Silhouette

The horizontal alignment signs may be used in advance of situations where the horizontal roadway alignment…

"The threads of the screw act upon the teeth cut into the wheel. As the screw turns, each thread catches a tooth on the wheel to rotate the wheel indefinitely." —Quackenbos 1859

Endless Screw

"The threads of the screw act upon the teeth cut into the wheel. As the screw turns, each thread catches…

A lathe is a machine tool which spins a block of material to perform various operations such as cutting, sanding, knurling, drilling, or deformation with tools that are applied to the workpiece to create an object which has symmetry about an axis of rotation.

Foot-power Wood-working Lathe

A lathe is a machine tool which spins a block of material to perform various operations such as cutting,…

"A key is used to turn the cone, B. By doing so it wraps the chain around the cone and tightly coils the spring inside the barrel, A. The spring draws the chain off of the cone turning the barrel." —Quackenbos 1859

The Fusee

"A key is used to turn the cone, B. By doing so it wraps the chain around the cone and tightly coils…

A cultivator that pulverizes or smooths the soil

Agricultural Harrow

A cultivator that pulverizes or smooths the soil

A lathe is a machine tool which spins a block of material to perform various operations such as cutting, sanding, knurling, drilling, or deformation with tools that are applied to the workpiece to create an object which has symmetry about an axis of rotation.

Large Power Lathe

A lathe is a machine tool which spins a block of material to perform various operations such as cutting,…

The pole lathe of 1800 is a wood turning tool that uses a pole as a return spring for the treadle (foot pedal).

Pole Lathe

The pole lathe of 1800 is a wood turning tool that uses a pole as a return spring for the treadle (foot…

The horizontal alignment Curve may be used in advance of situations where the horizontal roadway alignment changes.

Left Curve, Black and White

The horizontal alignment Curve may be used in advance of situations where the horizontal roadway alignment…

The horizontal alignment Curve may be used in advance of situations where the horizontal roadway alignment changes.

Left Curve, Color

The horizontal alignment Curve may be used in advance of situations where the horizontal roadway alignment…

The horizontal alignment Curve may be used in advance of situations where the horizontal roadway alignment changes.

Left Curve, Outline

The horizontal alignment Curve may be used in advance of situations where the horizontal roadway alignment…

The horizontal alignment Curve may be used in advance of situations where the horizontal roadway alignment changes.

Left Curve, Silhouette

The horizontal alignment Curve may be used in advance of situations where the horizontal roadway alignment…

"Wheel consists of flaps in the shape of buckets that are equally spaced. As water flows onto the wheel, the weight of the water in the buckets causes the wheel to rotate and empty the buckets." —Quackenbos 1859

Overshot Wheel

"Wheel consists of flaps in the shape of buckets that are equally spaced. As water flows onto the wheel,…

"Power is applied to the head of the screw. Each time the screw is turned into the nut, it advances the distance between two of the threads and compresses to that extent any fixed object against which it is directed." —Quackenbos 1859

Screw and Nut

"Power is applied to the head of the screw. Each time the screw is turned into the nut, it advances…

In electronics, a switch is an electrical component that can break an electrical circuit, interrupting the current or diverting it from one conductor to another.

Electric Switch Handle

In electronics, a switch is an electrical component that can break an electrical circuit, interrupting…

A toy having one end tapered to a point, allowing it to be spun, as by suddenly pulling a string wound around it.

Yoyo Top

A toy having one end tapered to a point, allowing it to be spun, as by suddenly pulling a string wound…

"Water enters through J and K following into G and H compartments. Afterwards the water is forced into the outside compartments thus turning the wheel." —Quackenbos 1859

Water Turbine

"Water enters through J and K following into G and H compartments. Afterwards the water is forced into…

"Waterwheel where the lowest flat-board is submerged in the running water. The water is often given its power from a slight inclination. This wheel is also often powered by the running water issued by a dam." —Quackenbos 1859

Undershot Wheel

"Waterwheel where the lowest flat-board is submerged in the running water. The water is often given…

A wheel is a circular device that is capable of rotating on its axis, facilitating movement and transportation.

Side View of a Vehicle Wheel

A wheel is a circular device that is capable of rotating on its axis, facilitating movement and transportation.

A wrench used for turning soft iron pipes and fittings with a rounded surface.

Pipe Wrench

A wrench used for turning soft iron pipes and fittings with a rounded surface.