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Illustration used to show that "In equal circles, or in the same circle, if two chords are unequal, the greater chord subtends the greater minor arc; conversely, if two minor arcs are unequal, the chord that subtends the greater arc is the greater."

Unequal Chords in Circles Theorem

Illustration used to show that "In equal circles, or in the same circle, if two chords are unequal,…

Illustration used to show that "In equal circles, or in the same circle, if two chords are equal, they are equally distant from the center; conversely, if two chords are equally distant from the center, they are equal."

Equal Chords in Equal Circles Theorem

Illustration used to show that "In equal circles, or in the same circle, if two chords are equal, they…

Illustration used to show that "In equal circles, or in the same circle, if two chords are unequal, the greater chord is at the less distance from the center."

Unequal Chords in Equal Circles Theorem

Illustration used to show that "In equal circles, or in the same circle, if two chords are unequal,…

Illustration used to show that "In equal circles, or in the same circle, if two chords are unequal, the greater chord is at the less distance from the center."

Unequal Chords in Equal Circles Theorem

Illustration used to show that "In equal circles, or in the same circle, if two chords are unequal,…

Illustration used to show that "If two tangents are drawn from any given point to a circle, those tangents are equal."

Equal Tangents to Circle Theorem

Illustration used to show that "If two tangents are drawn from any given point to a circle, those tangents…

Illustration of three isosceles triangles with the same base AC but varying heights (as B gets farther from the base).

3 Isosceles Triangles Wit Equal Bases

Illustration of three isosceles triangles with the same base AC but varying heights (as B gets farther…

Illustration of a circle used to prove "All angles inscribed in the same segment are equal."

Angles Inscribed in the Same Segment Circle Proof

Illustration of a circle used to prove "All angles inscribed in the same segment are equal."

"Head not crested. Wings and tail rounded, of approximately equal lengths, and about as long as the body. Bill typically parine." Elliot Coues, 1884. Head and neck are black; cheeks and ear coverts are white; male has a thick black strip going through its yellow breast; upper parts are olive; and outer tail feathers and wing bars are white

European Greater Titmouse

"Head not crested. Wings and tail rounded, of approximately equal lengths, and about as long as the…

"Upper parts pale brownish-gray, minutely dotted with blackish and whitish points together, and usually showing obsolete wavy bars of dusky. Rump cinnamon-brown; a whitish superciliary line. Beneath, soiled white, shading behind into pale cinnamon, the throat and breast obsoletely streaked, and the under tail-covers barred, with dusky. Quills of the wings rather darker than the back, with similar markings on the outer webs. Middle tail-feathers like the back, with many dark bars of equal width with the lighter ones; lateral tail-feathers similarly marked on the outer webs, plain on the inner webs, with a broad subterminal black bar on both webs, and cinnamon-brown tips, the latter usually marbled with dusky; outer feathers with several blackish and cinnamon bars on both webs. Bill and feet dark horn color, the former paler at base below." Elliot Coues, 1884

Rock Wren

"Upper parts pale brownish-gray, minutely dotted with blackish and whitish points together, and usually…

"Relative positions of the earth and the sun on March 21 (spring equinox) and September 21 (autumn equinox) as seen from the position occupied by the earth on June 21 (summer solstice). Rays of light and heat meet the earth vertically on the Equator, and the days and nights are everywhere of equal length." -Wiswell, 1913

Spring Equinox and Autumn Equinox

"Relative positions of the earth and the sun on March 21 (spring equinox) and September 21 (autumn equinox)…

The Wimshurst Machine is an electrostatic device to generate high voltages. "It consists of two circular glass plates, mounted on a common spindle, and capable of rotation in opposite directions with equal speeds. Each plate carries twelve or sixteen strips of thin sheet-metal, fixed radially at regular intervals apart ... At the extremities of the horizontal diameter of the plates the main conductors are placed, insulated on glass or vulcanite pillars." -Hazeltine, 1894

Wimshurst Machine

The Wimshurst Machine is an electrostatic device to generate high voltages. "It consists of two circular…

"Bill small, short, straight, very acute, more or less compressed, the lateral outlines usually a little concave, those of culmen and gonys straight; commissure straight to the slight angulation. Base of bill thickly beset with a ruff of antrorse plumules, concealing the small nasal fossae and round nostrils. Wings longer than tail, pointed by first 3 primaries. Tail rather long for this group, forked. Feet small and weak, but tarsi longer than middle toes without claw; lateral toes of equal lengths, their claw-tips falling beyond base of middle claw. Hind claw much longer, stouter and more curved than the middle, exceeding its digit in length. Size small; plumage streaky with dusky, white, and flaxen colors, crown crimson, face and throat blackish; sexes otherwise dissimilar; with rosy or carmine on breast, wanting in. Scarcely different from Linota (flavirostris, etc.) the pattern of coloration being the most available distinction." Elliot Coues, 1884

Red-poll Linnets

"Bill small, short, straight, very acute, more or less compressed, the lateral outlines usually a little…

"Passerculs bairdi. Baird's Savanna Sparrow. Inner secondaries less elongated, rarely equaling the primaries in the closed wings. First 4 quills about equal and longest. Hind toe and claw about equaling the middle toe and claw, its claw about equaling the digit. Tail shorter than wing, lightly double-rounded (central and outer pair of feathers both little shorter than the intermediate ones). Top of head streaked with black and rich brownish-yellow. or buff, the former predominating laterally, the latter chiefly as a median stripe, but also suffusing the nape and sides of head in greater or less degree. Back varied with brownish-black and gray, together with a little bay, the two latter colors forming the edgings of the interscapulars. Rump variegated with gray and chestnut-brown, different in shade from that of the back. Under parts dull white, usually with a faint ochrey tinge on the breast, but often without; a circlet of small, sharp, sparse, dusky streaks across the breast, continuous with others, longer and mostly lighter, along the whole sides, and with others, again, extending up the sides of the neck into small vague maxillary and aurigular markings. When the feathers are perfectly arranged these lateral head-markings are seen to be post-ocular stripe just over the auricular spot, a streak starting from the angle of the mouth, and another heavier one parallel with and below this, running directly into the pectoral ones. Quills without special marking, excepting the elongated inner secondaries, which correspond with scapulars. Tail the same, slightly whitish-edge. Upper mandible mostly dark, lower pale. Feet flesh-colored." Elliot Coues, 1884

Baird's Sparrow

"Passerculs bairdi. Baird's Savanna Sparrow. Inner secondaries less elongated, rarely equaling the primaries…

"Ammodramus. Seaside Sparrow. Bill remarkably slender and lengthened for this family, with culmen toward end, gonys straight, and sometimes an evident lobation of the cutting edge of the upper mandible. Wings short and rounded, yet longer than tail; inner secondaries, though not elongate, reaching nearly to end of primaries when wing is closed; point formed by 2d-4th quills. Feet large and stout, reaching outstretched about to the end of tail; tarsus about equal to middle toe and claw in length; lateral toes of equal lengths, very short, their claws under reaching base of middle claw. Tail shorter or not longer than wings, much rounded, of narrow, stiffish, sharp-pointed feathers. Embracing small streaky marsh sparrows, especially of the sea-coast, but not exclusively maritime, as long supposed; remarkable for slenderness of the bill, sharp narrow tail-feathers, and stout feet fitted for grasping slender swaying reeds. Edge of wing bright yellow; a yellow spot of buff stripe on head; upper parts olive-gray or quite blackish, streaky." Elliot Coues, 1884

The Details of a Seaside Sparrow

"Ammodramus. Seaside Sparrow. Bill remarkably slender and lengthened for this family, with culmen toward…

"Corvus monedul. Jackdaw. The species throughout uniform lustrous black, including the bill and feet; nasal bristles about half as long as the bill, which exhibits the typical cultrirostral style. Nostrils large, but entirely concealed. Wings much longer than tail, folding about to its end. Several outer primaries sinuate-attenuate on inner webs. Tail rounded, with broad feathers, sinuate-truncate at ends, with mucronate shafts. Feet stout; tarsus more or less nearly equal to middle toe and claw, roughly scutellate in front, laminar behind, with a set of small plates between." Elliot Coues, 1884

jackdaw

"Corvus monedul. Jackdaw. The species throughout uniform lustrous black, including the bill and feet;…

"Picus major. European Spotted Woodpecker. Bill more or less nearly equal to head in length, stout, straight, truncate at tip, bevelled toward end, with sharp culmen and distinct lateral ridges on upper mandible; at base rather broader than high, with large nasal tufts hiding the nostrils; culmen, commissure and gonys straight or nearly so. Feet with the outer posterior longer than outer anterior toe; inner anterior intermediate between these. Wing long, pointed by the 4th, 3d, and 5th quills; 2d decidedly shorter (shorter than 7th, except in P. borealis); 1st fairly spurious. Species of medium and small size. All black and white (one brown-backed), the back striped or barred, the wings with numerous small round white spots on the quills; Male with red on the head." Elliot Coues, 1884

European Spotted Woodpecker

"Picus major. European Spotted Woodpecker. Bill more or less nearly equal to head in length, stout,…

"Surnia funerea. American Hawk Owl. Day Owl. Bill and eyes yellow; claws brownish-black. Upper parts bistre-brown, darkest and almost blackish on the head, where profusely spotted with small round white mark, to which succeeds a nuchal interval less spotted or free from spots, then an area of larger and lengthened spots; scapulars profusely spotted with white in large pattern, forming a scapular bar as in Scops; back and wing-coverts more or less spotted with white also; primaries and secondaries with with white spots in pairs on opposite edges of the feathers. Tail broken-barred with white or pale gray, usually narrowly and distinctly, on one or both webs, and tipped with the same; but there is great individual variation in this respect, as may also be said of the amount and character of the spotting of the upper parts. Under parts from the breast backward, including the crissum, closely and regularly cross-barred with rich reddish-brown, or even reddish-brown, or even reddish-black, upon a white ground, the alternating bars of color usually of about equal widths - if anything, the white the broadest.

Hawk Owl

"Surnia funerea. American Hawk Owl. Day Owl. Bill and eyes yellow; claws brownish-black. Upper parts…

The St-Paul-St-Louis Church is located in Paris on Rue Saint Antoine in the Marais. The church was begun in 1627 and completed in 1641 and is an examaple of Jesuit architecture. It was designed based on the Gesú church in Rome. The letters IHS, as shown on the front of the church, is an abbreviation, the first three letters, of Jesus' name in Greek, ΙΗΣΟΥΣ, translated into English characters. "In this style curved lines of the most varied description supersede all straight lines both in ground plans and in designs, whilst the most ordinary and characteristic embellishments are volutes, shellfish, and scrolls; groups of fruit and garlands of flowers, hangings, curtains, etc. [shown here]." "During the time that the license of the Roccoco Style prevailed, the elements of the ancient columnar orders were often misapplied, engaged columns and pilasters were frequently so connected with other side-pilasters which were recessed behind them to the number of one, two, or even three, that the cornices and, in fact, all horizontal mouldings were separately profiled over each column or pilaster [shown here]."

Façade of the Church of St. Paul and St. Louis at Paris

The St-Paul-St-Louis Church is located in Paris on Rue Saint Antoine in the Marais. The church was begun…

"Ardea. Great Herons. Of largest size, former well feathered all around. Tibia extensively denuded below. Tarsus longer than middle toe and claw. Outer lateral toe longer than inner. Bill shorter than tarsus, equal to or longer than middle toe and claw. Colors dark and varied, exceptionally white; back without lengthened loosened plumes; scapulars lanceolate, lengthened, but not loosened; lower fore-neck with lengthened feathers; head crested, in breeding season with two long, slender, flowing, occipital plumes. Sexes alike; young similar, but lacking all lengthened feathers." Elliot Coues, 1884

Heron

"Ardea. Great Herons. Of largest size, former well feathered all around. Tibia extensively denuded below.…

"Parra. Jacanas. Bill plover-like, contracted in continuity, enlarged terminally; with culmen depressed to end of nasal groove, then convex and decurved; outline of mandibular rami about straight to the gonys, which is ascending; commissure about straight to the decurved end. Nasal grooves along the contracted portion of the bill; nostrils small, elliptical, situate in advance of the base of the bill. Angle of mouth with a leaf-like lobe of skin (rudimentary in our species). Forehead with a large leaf-like lobe of skin, with free lateral and posterior edges, adherent centrally and anteriorly where reaching base of upper mandible. A sharp horny spur on bend o wing Primaries 10, not peculiar in structure; outer 3 about equal and longest, overlaid by the inner quills in the closed wing. Tail very short, with soft rectrices concealed be the coverts. Tibia bare below, and with the tarsus scutellate before and behind, the scutella tending to become confluent in a continuous sheath. All the toes, claws included, longer than tarsus; middle toe alone nearly as long as tarsus; outer toe alone about as long as middle, its claw shorter than that of middle toe; inner toe a little shorter than outer, its claw longer; hind toe only about as long as basal joint of middle toe, but its claw much longer than itself; all the claws slender, about straight, very acute." Elliot Coues, 1884

Parra Jacana

"Parra. Jacanas. Bill plover-like, contracted in continuity, enlarged terminally; with culmen depressed…

"Fuligula ferina americana. Red-head. American Pochard. The feathers of the head somewhat full and puffy, though forming no crest. Bill broad and flattened, a little widened toward end, running into the forehead which arches abruptly over and away from it, not rising gradually into line with forehead; shorter or not longer than head, 2 inches or less in length along culmen, the nostrils within its basal half; the forward end of nostril about 2/5 the way from upper corner to end of bill. Bill dull blue with a black belt at the end. Iris orange. Feet dull grayish-blue, with dusky webs and black claws. Head and neck all around rich pure chestnut, not obscured with dusky-brown, but with bronzy or coppery red reflections. Lower neck and fore parts of body above and below, with rump and tail-coverts above and below, blackish. Back mixed whitish and blackish in about equal amounts, the dark wavy lines distinct and unbroken. Sides of the body under the wings vermiculated much like the back, the undulations subsiding in the grayish-white of the middle under parts. Wing-coverts ashy-gray, minutely dotted with white; speculum hoary-ash, bordered internally with black; lining of wings mostly white. Female: Bill obscured bluish, with black belt near end; iris yellow." Elliot Coues, 1884

Small Redhead

"Fuligula ferina americana. Red-head. American Pochard. The feathers of the head somewhat full and puffy,…

"Fuligula ferina americana. Red-head. American Pochard. The feathers of the head somewhat full and puffy, though forming no crest. Bill broad and flattened, a little widened toward end, running into the forehead which arches abruptly over and away from it, not rising gradually into line with forehead; shorter or not longer than head, 2 inches or less in length along culmen, the nostrils within its basal half; the forward end of nostril about 2/5 the way from upper corner to end of bill. Bill dull blue with a black belt at the end. Iris orange. Feet dull grayish-blue, with dusky webs and black claws. Head and neck all around rich pure chestnut, not obscured with dusky-brown, but with bronzy or coppery red reflections. Lower neck and fore parts of body above and below, with rump and tail-coverts above and below, blackish. Back mixed whitish and blackish in about equal amounts, the dark wavy lines distinct and unbroken. Sides of the body under the wings vermiculated much like the back, the undulations subsiding in the grayish-white of the middle under parts. Wing-coverts ashy-gray, minutely dotted with white; speculum hoary-ash, bordered internally with black; lining of wings mostly white. Female: Bill obscured bluish, with black belt near end; iris yellow." Elliot Coues, 1884

Large Redhead

"Fuligula ferina americana. Red-head. American Pochard. The feathers of the head somewhat full and puffy,…

"Fuligula ferina americana. Red-head. American Pochard. The feathers of the head somewhat full and puffy, though forming no crest. Bill broad and flattened, a little widened toward end, running into the forehead which arches abruptly over and away from it, not rising gradually into line with forehead; shorter or not longer than head, 2 inches or less in length along culmen, the nostrils within its basal half; the forward end of nostril about 2/5 the way from upper corner to end of bill. Bill dull blue with a black belt at the end. Iris orange. Feet dull grayish-blue, with dusky webs and black claws. Head and neck all around rich pure chestnut, not obscured with dusky-brown, but with bronzy or coppery red reflections. Lower neck and fore parts of body above and below, with rump and tail-coverts above and below, blackish. Back mixed whitish and blackish in about equal amounts, the dark wavy lines distinct and unbroken. Sides of the body under the wings vermiculated much like the back, the undulations subsiding in the grayish-white of the middle under parts. Wing-coverts ashy-gray, minutely dotted with white; speculum hoary-ash, bordered internally with black; lining of wings mostly white. Female: Bill obscured bluish, with black belt near end; iris yellow." Elliot Coues, 1884

Redheads

"Fuligula ferina americana. Red-head. American Pochard. The feathers of the head somewhat full and puffy,…

"Larus heermanni. White-headed Gull. Bill shorter than head or tarsus, rather slender, moderately compressed, the tip rather acute; its color red in part in the adult. Folded wings reaching beyond the tail. Tail of moderate length, even, slightly emarginate in the young. Feet rather large. Tarsus equal to the middle toe and claw. General colors dark; tail mostly blackish. Adult, breeding plumage: Bill bright vermilion red, black for its terminal third, sometimes wholly red; a red ring around eye. Head white; this color gradually merging on the neck into plumbeous-ash, which extends over the whole under parts, being lighter on the abdomen and under tail-coverts than elsewhere. The back is deep plumbeous-slate, lighter on the rump. Upper tail-coverts clearly ashy. Upper surfaces of wings like the back; the primaries black; the tips of all, except the two or three outer ones, narrowly white. Tail black, narrowly tipped with white. Legs and feet reddish-black." Elliot Coues, 1884

White-headed Gull Head

"Larus heermanni. White-headed Gull. Bill shorter than head or tarsus, rather slender, moderately compressed,…

"Uria grylle. Black Guillemots. Bill much shorter than head, about equal to tarsus, straight, rather stout, moderately compressed; culmen at first straight, then decurved; gape straight to near tip; gonys short straight, ascending, about 1/2 as long as culmen. No nick or groove near tip of upper mandible; its tomial edge scarcely inflected. Nasal fossae large and deep, partially filled with feathers which do not entirely cover the nostrils." Elliot Coues, 1884

Black Guillemot Bill

"Uria grylle. Black Guillemots. Bill much shorter than head, about equal to tarsus, straight, rather…

"Draw three-inch square. Draw lines AB, BC, DE and EF at 30 degrees. Divide lower side into seven equal parts with the dividers. Draw the vertical lines, and mark divisions on AC with pencil as each line is drawn. Through the division points on top and bottom draw the converging lines using the triangle alone as a straight-edge." —French, 1911

Drawing Converging Lines

"Draw three-inch square. Draw lines AB, BC, DE and EF at 30 degrees. Divide lower side into seven equal…

"Draw a circle three inches in diameter. Divide the circumference into five equal parts by trial with dividers. From these points draw radial lines and divide each into four equal parts with spacers. With these points as centers draw the semicircles as shown The radial lines are not to be inked." —French, 1911

Drawing Tangent Arcs with Compass and Dividers

"Draw a circle three inches in diameter. Divide the circumference into five equal parts by trial with…

"On base AB, 3 1/2" long construct an equilateral triangle, using the 60-degree triangle. Bisect the angles with the 30-degree angle, extending the bisectors to the opposite sides. With these middle points of the sides as centers and radius equal to 1/2 the side, draw arcs cutting the bisectors. These intersection will be centers for the inscribed circles. With centers on the intersection of these circles and the bisectors, round off the points of the triangle as shown." —French, 1911

Drawing Tangent Circles and Lines with Compass and Triangles

"On base AB, 3 1/2" long construct an equilateral triangle, using the 60-degree triangle. Bisect the…

"At A draw the tangent AD and Chord AB produced. Lay off AC equal to half the chord AB. With center C and radius CB draw an arc intersecting AB at E, then AE will be equal in length be to the arc AB." —French, 1911

Approximating Length of Circle Arc using Straight Line

"At A draw the tangent AD and Chord AB produced. Lay off AC equal to half the chord AB. With center…

Create diameters with major, minor axes, or a pair of conjugate diameters. Construct a parallelogram, then divide into equal parts creating intersections for the curve.

Construction of Ellipse using Parallelogram

Create diameters with major, minor axes, or a pair of conjugate diameters. Construct a parallelogram,…

"Join A and D. Lay off DF equal to AC-DC. Bisect AF by a perpendicular crossing AC at G and intersecting DE produced at H. Make CG' equal to CG and CH' equal to CH. Then G, G', H, and H' will be centers for four arcs approximating the ellipse. The half of this ellipse when used in masonry construction is known as the three-centered arch." —French, 1911

Approximate Ellipse with Four Centers

"Join A and D. Lay off DF equal to AC-DC. Bisect AF by a perpendicular crossing AC at G and intersecting…

"When the minor axis is at least two-thirds the major, the following method ma be used: Make CF and CG equal to AB-DE. Make CH and CI equal to 3/4 CF F, G, H, I will be centers for arcs E, D, B, and A." —French 1911

Approximate Ellipse using Lines

"When the minor axis is at least two-thirds the major, the following method ma be used: Make CF and…

"Divide the circumference into a number of equal parts, drawing the radii and numbering the points. Divide the radius No. 1 into the same number of equal parts, numbering from the center. With C as center draw concentric arcs intersecting the radii of corresponding numbers, and draw a smooth curve through these intersections." —French, 1911

Draw Spiral of Archimedes

"Divide the circumference into a number of equal parts, drawing the radii and numbering the points.…

"For the first practice draw in pencil top and bottom guide lines for 3/16" letters and with a 516 F or similar pen make directly in ink a series of vertical lines, drawing the pen down with a finger movement. This one stroke must be practised until the beginner can get lines vertical and of equal weight." —French, 1911

Top View of Position for Lettering Using Pen

"For the first practice draw in pencil top and bottom guide lines for 3/16" letters and with a 516 F…

This machine is used for multiplication, and division purposes. Multiplication is the mathematical operation of scaling one number by another. It is one of the four basic operations in elementary arithmetic. Conceptually, division describes two distinct but related settings. Partitioning involves taking a set of size a and forming b groups that are equal in size. The size of each group formed, c, is the quotient of a and b. Quantitate division involves taking a set of size a and forming groups of size b. The number of groups of this size that can be formed, c, is the quotient of a and b

Multiplying or Dividing Machine

This machine is used for multiplication, and division purposes. Multiplication is the mathematical operation…

An image of a hexagonal pyramid stretched out. The length of the edges are equal plane, and intersects the at the perimeter of the base.

Development of Hexagonal Pyramid

An image of a hexagonal pyramid stretched out. The length of the edges are equal plane, and intersects…

The illustration of a rectangular pyramid unfolded by creating edges equal length to the base and meeting at point E.

Development of Rectangular Pyramid

The illustration of a rectangular pyramid unfolded by creating edges equal length to the base and meeting…

A rolled out image of a cone by dividing the base in equal parts and arcs to measure the true lengths.

Development of Cone

A rolled out image of a cone by dividing the base in equal parts and arcs to measure the true lengths.

An illustration in flattening the sphere using Gore method by creating cylinder sections with equal diameters.

Development of Sphere Gore Method

An illustration in flattening the sphere using Gore method by creating cylinder sections with equal…

A pump is a device used to move fluids, such as liquids or slurries, or gases. A pump displaces a volume by physical or mechanical action. One common misconception about pumps is the thought that they create pressure. Pumps alone do not create pressure; they only displace fluid, causing a flow. Adding resistance to flow causes pressure. Pumps fall into five major groups: direct lift, displacement, velocity, buoyancy and gravity pumps, and their names describe the method for moving a fluid.

Mechanical Action Air Pump

A pump is a device used to move fluids, such as liquids or slurries, or gases. A pump displaces a volume…

"The intersection of two cylinders might represent a dome on a boiler. If the top view of cylinder A is divided into a number of equal parts the points will represent the top views of elements."—French, 1911

Intersection of Two Cylinders

"The intersection of two cylinders might represent a dome on a boiler. If the top view of cylinder A…

Exercise problem to develop, or rolled out, image of the triangular pyramid by creating an equal length of the edges of each triangle.

Development Exercise of Triangular Pyramid

Exercise problem to develop, or rolled out, image of the triangular pyramid by creating an equal length…

A sample exercise problem in completing the top part of the hexagonal pyramid and to create a development, or stretched out, of the image by creating edges at equal lengths, and revolving the sides.

Development Exercise of Hexagonal Pyramid

A sample exercise problem in completing the top part of the hexagonal pyramid and to create a development,…

Development and top completion exercise problem of the cone by dividing the base into equal parts and creating an arc to revolve the sides of the plane.

Development Exercise of Cone

Development and top completion exercise problem of the cone by dividing the base into equal parts and…

A van is a kind of vehicle used for transporting goods or groups of people. It is usually a box-shaped vehicle on four wheels, about the same width and length as a large automobile, but taller and usually higher off the ground.

Provision Type Tour Van

A van is a kind of vehicle used for transporting goods or groups of people. It is usually a box-shaped…

Fertilizers are roughly broken up between organic and inorganic fertilizer, with the main difference between the two being sourcing, and not necessarily differences in nutrient content. Broadcast seeders/spreaders can be roughly divided into three groups. The smallest of the broadcast seeders/spreaders can be carried or pushed while spreading seed or fertilizer.

One Wheel Fertilizer Distributor

Fertilizers are roughly broken up between organic and inorganic fertilizer, with the main difference…

An illustration of sharpening a pen to equal shape and length using a a stone soaked in oil. The pen is held about 30 degrees, and drawing line back and forth until sharpened to desired shape and length.

Sharpening Pen using Stone

An illustration of sharpening a pen to equal shape and length using a a stone soaked in oil. The pen…

"As the bottom of the surface meets the air, it compresses it and accelerates it downwards. As a result of this definite action there is an equal and opposite reaction upwards." —Barber, 1917

Aerodynamic of Airplane Wing

"As the bottom of the surface meets the air, it compresses it and accelerates it downwards. As a result…

The illustration of an aeroplane, or airplane, propeller being balanced by using surface area testing. The length of the blade on opposite sides must be equal.

Aeroplane Propeller Balance Blade Surface Area

The illustration of an aeroplane, or airplane, propeller being balanced by using surface area testing.…

"The chamber (curvature) of the blades should be (1) equal, (2) decrease evenly towards the tips of the blades, (3) the greatest depth of the curve should, at any point of the blade, be approximately at the same percentage of the chord from the leading edge as at other points." —Barber, 1917

Aeroplane Propeller Balance Chamber

"The chamber (curvature) of the blades should be (1) equal, (2) decrease evenly towards the tips of…

The device used to create spheres by rotating the ball and mandrel to create an equal diameter. The wire is connected to the top and the wheel while spinning.

Device for Turning Sphere

The device used to create spheres by rotating the ball and mandrel to create an equal diameter. The…

A square threaded tap or screw with three equal lengthed thickness. The stepped tap is used to fasten two materials together with unthreaded top.

Stepped Threaded Tap

A square threaded tap or screw with three equal lengthed thickness. The stepped tap is used to fasten…

"This class of spirals may be generated by unwinding a perfectly flexible but inextensible chord from a polygon of any number of sides, the names of the involutes being derived from the polygons which determine their form. The curves consist of radii increasing by an amount equal to the length of the sides." —Anthony, 1904

Involute Spiral

"This class of spirals may be generated by unwinding a perfectly flexible but inextensible chord from…

"Since the valve must move a distance equal to the outside lap before admission can take place, it is evident that the eccentric can no longer be at right angles to the crank at the beginning of the stroke, but must be ahead of the right—angle point by an amount equal to AOC." —Derr, 1911

Valve with Lap of Steam Engine at Extreme Left with Exhaust Ports Open

"Since the valve must move a distance equal to the outside lap before admission can take place, it is…

"If the velocity of impact of the jet is V feet per second, its velocity in the same direction after striking the plate will be zero, a definite force will be exerted on that plate, equal to the force necessary to impart a velocity of V feet in one second to the mass of water in the jet." —Derr, 1911

Water Jet Deflected 90 Degrees Measuring Force

"If the velocity of impact of the jet is V feet per second, its velocity in the same direction after…

"Now if the plate were shaped as shown, so that the direction of the jet were completely reversed turned through 180 degrees, there would be an additional pressure on the plate, due to the reaction of the jet leaving it. This, neglecting friction, would be equal to the original impulse, thus making the total force on plate 2 F instead of F. It is quite evident that if the force is twice as great, the work must be double." —Derr, 1911

Force Measurement by Deflecting Water Jet 180 Degrees

"Now if the plate were shaped as shown, so that the direction of the jet were completely reversed turned…

"If a jet with the velocity V strikes the bucket at an angle a, its velocity A B could be resolved into two components —one C B at right angles to the shaft, and one C A parallel to the shaft. The one at right angles to the shaft, commonly known as the velocity of whirl, would produce a rotative impulse equal to Vcosa, and V1, the velocity of the vane necessary for maximum efficiency." —Derr, 1911

Jet Steam Stream Hitting Curved Vane

"If a jet with the velocity V strikes the bucket at an angle a, its velocity A B could be resolved into…

"Polypodium widely distributed throughout the world, but specially developed in the tropics. The species differ greatly in size and general appearance and in the character of the frond; the sori or groups of spore—cases (sporangia) are borne on the back of the leaf, are globose and naked, that is, are not covered with a membrane (indusium)." —Encyclopaedia Britannica Company, 1910

Common Polypody Leaf with Sori

"Polypodium widely distributed throughout the world, but specially developed in the tropics. The species…

The Minorcas are similar to the Leghorns, with their main value being egg-producing. The produce less eggs than the Leghorns, but their eggs are generally larger, and equal the output in bulk.

Black Minorca Cockerel

The Minorcas are similar to the Leghorns, with their main value being egg-producing. The produce less…

"Fork-veined leaves are those in which the primary veins divide into two nearly equal secondary veins, forming a dork, and these subdivided in the same manner."—Darby, 1855

Fork-Veined Leaf

"Fork-veined leaves are those in which the primary veins divide into two nearly equal secondary veins,…