"Boit's experiment which proved tat the charge resides on the surface." -Hawkins, 1917

Boit's Experiment

"Boit's experiment which proved tat the charge resides on the surface." -Hawkins, 1917

Circle modeling the earth. O is the center of the earth, r the radius of the earth, and h the height of the point P above the surface; it is required to find the distance from the point P to the horizon at A.

Circle With Center o and Radius r with point P

Circle modeling the earth. O is the center of the earth, r the radius of the earth, and h the height…

Illustration of blueprint used by highway engineers to widen the pavement on the inside of the curve of a road.

Curve in Pavement of Road

Illustration of blueprint used by highway engineers to widen the pavement on the inside of the curve…

"An inclined plane is a slope, or a flat surface, making an angle with a horizontal line...the force acts at an angle to the plane or to the base." —Hallock 1905

Inclined Plane with Force at an Angle to Plane and Base

"An inclined plane is a slope, or a flat surface, making an angle with a horizontal line...the force…

"An inclined plane is a slope, or flat surface, making an angle with a horizontal line...the force acts parallel to the base." —Hallock 1905

Inclined Plane with the Force Acting Parallel to the Base

"An inclined plane is a slope, or flat surface, making an angle with a horizontal line...the force acts…

"An inclined plane is a slope, or flat surface, making an angle with a horizontal line...the force acts parallel to the plane." —Hallock 1905

Inclined Plane with the Force Acting Parallel to the Plane

"An inclined plane is a slope, or flat surface, making an angle with a horizontal line...the force acts…

Illustration modeling the illumination on a surface when the surface is not perpendicular to hte rays of light from a source of light.

Illumination of a Surface When the Surface is not Perpendicular to the Source

Illustration modeling the illumination on a surface when the surface is not perpendicular to hte rays…

"One of the primary simple mechanical powers. The plane's surface is inclined to the horizon at any angle." —Quackenbos 1859

Inclined Plane

"One of the primary simple mechanical powers. The plane's surface is inclined to the horizon at any…

A device used for determining or adjusting something to a horizontal surface.

Tool Level

A device used for determining or adjusting something to a horizontal surface.

"Surface of Palm of the Hand, showing Openings of Sweat Glands and Grooves between Papillae of the Skin. In the smaller figure the same epidermal surface is shown as seen with the naked eye." — Blaisedell, 1904

Surface of the palm

"Surface of Palm of the Hand, showing Openings of Sweat Glands and Grooves between Papillae of the Skin.…

"Summer and Winter rays.—Let us suppose that the rays falling perpendicularly on a given extent of surface, impart to it a certain degree of heat, then it is obvious, that if the same number of rays be spread over twice that extent of surface, their heating power would be diminished in proportion, and that only half of the heat would be imparted. This is the effect produced by the Sun's rays in the Winter. They fall so obliquely on the Earth, as to occupy nearly double the space that the same number of rays do in the Summer." —Comstock, 1850

Rays

"Summer and Winter rays.—Let us suppose that the rays falling perpendicularly on a given extent…

"Reflection of light from a broken surface." —Croft 1917

Reflection of Light from a Broken Surface

"Reflection of light from a broken surface." —Croft 1917

"Irregular reflection or diffusion results from the incidence of radiant energy upon an irregular surface, as is illustrated. Bodies are made visible to the eye mainly by the light that they thus diffuse." -Avery 1895

Irregular Reflection or Diffusion

"Irregular reflection or diffusion results from the incidence of radiant energy upon an irregular surface,…

"Reflection of light from a smooth surface." —Croft 1917

Reflection of Light from a Smooth Surface

"Reflection of light from a smooth surface." —Croft 1917

"Reflection of light form a smooth surface." —Croft 1917

Reflection of Light from a Smooth Surface

"Reflection of light form a smooth surface." —Croft 1917

A heraldic shield with a green surface, which is represented by the perpendicular lines, drawn from the head to the base of the shield.

Gules Shield

A heraldic shield with a green surface, which is represented by the perpendicular lines, drawn from…

A heraldic shield made of silver, which is represented by its plain, smooth surface.

Silver Shield

A heraldic shield made of silver, which is represented by its plain, smooth surface.

Separates wanted elements from unwanted material using a filter such as a mesh or net. However, in cooking, especially with flour, a sifter is used to aerate the substance, among other things. A strainer is a type of sieve typically used to separate a solid from

Separator and Sifter

Separates wanted elements from unwanted material using a filter such as a mesh or net. However, in cooking,…

Illustration comparing the fundamental units of measure 1 square yard and 1 square meter.

Comparison Of Units Of Square Measure

Illustration comparing the fundamental units of measure 1 square yard and 1 square meter.

"Carefully place a fine sewing needle upon the surface of the water. With care, and perhaps repitition, the needle may be made to float...Closely examine the surface of the water. Notice that the needle rests in a little depression or bed, just as it would if the surface of the water was a thin skin or membrane." -Avery 1895

Surface Tension and Needle

"Carefully place a fine sewing needle upon the surface of the water. With care, and perhaps repitition,…

Illustration of silo to show a curved surface

Curved Surface

Illustration of silo to show a curved surface

A movable device, especially a framed construction such as a room divider or a decorative panel, designed to divide, conceal, or protect.

Adjustable Window Screen

A movable device, especially a framed construction such as a room divider or a decorative panel, designed…

In masonry, is a term applied where surface of a wall shows groves between the different courses of stones, thus giving the appearance of open joints. There are many varieties of it.

Rustic Work Depictions

In masonry, is a term applied where surface of a wall shows groves between the different courses of…

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.