ClipArt ETC
"It will be seen that the parabolic mirror a is at best but a very imperfect instrument, for even if the radiant were strictly a mathematical point, the cone of rays (shown undotted) escaping past the lips of the mirror must be lost." —The Encyclopedia Britannica, 1910

Paraboloid

"It will be seen that the parabolic mirror a is at best but a very imperfect instrument, for even if…

A beautiful flower with a yellow central star.

American Centaury

A beautiful flower with a yellow central star.

A leaf shaped like a triangle.

Sagittate Leaf

A leaf shaped like a triangle.

"The whole length of the tube of the wheel barometer, from C to A, is 34 or 35 inches, and it is filled with mercury, as usual. The mercury rises in the short leg to the point a, where there is a small piece of glass floating on its surface, to which there is attached a silk string, passing over the pulley p. To the axis of the pulley is fixed an index, or hand, and behind this is a graduated circle, as seen in the figure. It is obvious, that a very slight variation in the height of the mercury at o, will be indicated by a considerable motion of the index, and thus changes in the weight of the atmosphere, hardly perceptible by the common barometer, will become quite apparent by this." —Comstock, 1850

Wheel Barometer

"The whole length of the tube of the wheel barometer, from C to A, is 34 or 35 inches, and it is filled…

"The refraction of water is beautifully proved by the following simple experiment. Place an empty cup, with a shilling on the bottom, in such a position that the side of the cup will just hide the piece of money from the eye. Then let another person fill the cup with water, keeping the eye in the same position as before. As the water is poured in, the shilling will be come visible, appearing to rise with the water. The effect of the water is to bend the ray of light coming from the shilling, so as to make it meet the eye below the point where it otherwise would. Thus the eye could not see the shilling in the direction of c, since the line, of vision is towards a, and c is hidden by the side of the cup. But the refraction of the water bends the way downwards, producing the same effect as though the object had been raised upwards, and hence it becomes visible." —Comstock, 1850

Cup and Shilling

"The refraction of water is beautifully proved by the following simple experiment. Place an empty cup,…

"Camera obscura strictly signifies a darkened chamber, because the room must be darkened, in order to observe its effects. To witness the phenomena of this instrument, let a room be closed in every direction, so as to exclude the light. Then from an aperture, say of an inch in diameter, admit a single beam of light, and the images of external things, such as trees and houses, and persons walking the streets, will be seen inverted on the wall opposite to where the light is admitted, or on a screen of white paper, placed before the aperture. The reason why the image is inverted will be obvious, when it is remembered that the rays proceeding from the extremities of the object must converge in order to pass through the small aperture; and as the rays of light always proceed in straight lines, they must cross each other at the point of admission. Thus the pencil a, coming from the upperpart of the tower, and proceeding straight, will represent the image of the part at b, while the lower part c, for the same reason, will be represented at d." —Comstock, 1850

Camera Obscura

"Camera obscura strictly signifies a darkened chamber, because the room must be darkened, in order to…

"Camera obscura strictly signifies a darkened chamber, because the room must be darkened, in order to observe its effects. To witness the phenomena of this instrument, let a room be closed in every direction, so as to exclude the light. Then from an aperture, say of an inch in diameter, admit a single beam of light, and the images of external things, such as trees and houses, and persons walking the streets, will be seen inverted on the wall opposite to where the light is admitted, or on a screen of white paper, placed before the aperture. The reason why the image is inverted will be obvious, when it is remembered that the rays proceeding from the extremities of the object must converge in order to pass through the small aperture; and as the rays of light always proceed in straight lines, they must cross each other at the point of admission. Thus the pencil a, coming from the upperpart of the tower, and proceeding straight, will represent the image of the part at b, while the lower part c, for the same reason, will be represented at d." —Comstock, 1850

Camera Obscura

"Camera obscura strictly signifies a darkened chamber, because the room must be darkened, in order to…

"Let S be the Sun, E the Earth, and A, B, C, D, F, the Moon in different parts of her orbit. Now when the Moon changes, or is in conjunction with the Sun, as at A, her dark side is turned towards the Earth, and she is invisible, as represented at a. The Sun always shines on one half of the Moon, in every direction, as represented at A and B, on the inner circle; but we at the Earth can see only such portions of the enlightened part as are turned towards us. After her change, when she has moved from A to B, a small part of her illuminated side comes in sight, and she appears horned, as at b, and is then called the new Moon. When she arrives at C, severel days afterwards, one half of her disc is visible, and she appears as at c, her appearance being the same in both circles. At this point she is said to be in her first quarter, because she has passed through a quarter of her orbit, and is 90 degrees from the place of her conjunction with the Sun. At D, she shows us still more of her enlightened side, and is then said to appear gibbous as at d. When she comes to F, her whole enlightened side is turned towards the Earth, and she appears in all the spendor of a full Moon." —Comstock, 1850

Moon Phases

"Let S be the Sun, E the Earth, and A, B, C, D, F, the Moon in different parts of her orbit. Now when…

"Umbra and Penumbra. A solar eclipse, with the penumbra, d, c, and the umbra or dark shadow is seen here. When the Moon is at its greatest distance from the Earth, its shadow m o, sometimes terminates, before it reaches the Earth, and then an observer standing directly under the point o, will see the outer edge of the Sun, forming a bright ring around the circumference of the Moon, thus forming an annular eclipse." —Comstock, 1850

Umbra

"Umbra and Penumbra. A solar eclipse, with the penumbra, d, c, and the umbra or dark shadow is seen…

"If we suppose a spectator placed at G, in the Earth's center, he would see the moon E, among the stars at I, whereas without changing the position of the moon, if that body is seen from A, on the surface of the Earth, it would appear among the stars at K. Now I is the true and K the apparent place of the moon, the space between them, being the Moon's parallax." —Comstock, 1850

Diurnal Parallax

"If we suppose a spectator placed at G, in the Earth's center, he would see the moon E, among the stars…

"Suppose a to be a stationary celestial object, then as the Earth makes her annual revolution around the Sun S, this object at one time will appear among the stars at e, but six months after, when the Earth comes to the opposite point in her orbit, the same object will be seen at c, the space from c to e being the annual parallax of the object a. But the distances of the stars are so great that the diameter of the Earth's orbit, or 190,000,000 of miles make no difference in their apparent places. Were the fixed stars within 19 trillions of miles, their distance could be told by their parallaxes." —Comstock, 1850

Annual Parallax

"Suppose a to be a stationary celestial object, then as the Earth makes her annual revolution around…

"Diagram illustrating the points at which incident rays meet the retina. xx, optic axis; k, first nodal point; k', second nodal point; b, point where the image of B would be formed, were the eye properly accommodated for it; a, the retinal point where the image of A would be formed." —Martin, 1917

Retina

"Diagram illustrating the points at which incident rays meet the retina. xx, optic axis; k, first nodal…

"Diagrammatic section through the eyeball. xx, optic axis; k, nodal point." —Martin, 1917

Retina

"Diagrammatic section through the eyeball. xx, optic axis; k, nodal point." —Martin, 1917

"At sea the declination is generally observed by means of an azimuth compass invented by Kater. It consists of a magnet with a graduated compass card attached to it. At the side of the instrument opposite the eye there is a frame which projects upwards from the plane of the instrument in a nearly vertical direction, and this frame contains a wide rectangular slit cut into two parts by a wire extending lengthwise. The eye-piece is opposite this frame, and the observer is supposed to point the instrument in such a manner that the wire above mentioned shall bisect the sun's visible disk. There is a totally reflecting glass prism which throws into the eye-piece an image of the scale of the graduated card, so that the observer, having first bisected the sun's disk by the wire, must next read the division of the scale which is in the middle of the field of view." —The Encyclopedia Britannica, 1903

Azimuth Compass

"At sea the declination is generally observed by means of an azimuth compass invented by Kater. It consists…

A chinese flower. It abounds in a volitale oil which gives it an aromatic flavor and odor. Used as a condiment in China and India.

Star Anise

A chinese flower. It abounds in a volitale oil which gives it an aromatic flavor and odor. Used as a…

This figure represents the whole of the points and lines requisite for working out a drawing in "parallel perspective." 1) The point of sight; 2)The horizontal line; 3) The point of station; 4) The points of measurement.

Parallel Perspective

This figure represents the whole of the points and lines requisite for working out a drawing in "parallel…

This figure comprises the whole of the points and lines preparatory to beginning a drawing in "angular perspective." 1) The point of sight; 2)The horizontal line; 3) The point of station; 4) The nearest corner of the object to be drawn; 5) The ground line of the building or object, lying on that side, and produced from the nearest corner up to the horizontal line, in order to determine the vanishing point marked 5; 6) A line taken from the vanishing point 5, to the point of station 3; 7) A line drawn at right angles to 6, and extending from the point of station to the horizontal line, at its junction with which the vanishing point, marked 8, is determined; 9) A point of measurement obtained by the use of the vanishing point 8; 10) The other point of measurement, obtained by vanishing point 5; 11) The geometrical scale of the building or object upon a base line drawn through the nearest corner.

Angular Perspective

This figure comprises the whole of the points and lines preparatory to beginning a drawing in "angular…

The perspective shown in this plate is parallel perspective; and the subject here intended to be represented is a flat and perfectly square surface, such as the floor of a room, a chess board, or any other such object. 1) The front edge of the given square; 2) One side of it receding to the vanishing point, which also is the point of sight; 3) The other side receding to the same point; 4) A line taken from one corner of the front edge, to the point of measuremen on the opposite side, and giving the perspective width or depth of the square at the intersection of the line 3; 5) A line drawn at the above intersection, and parallel to the front edge; this will give the back of the square. The lines 1, 2, 3, and 5 may then be strongly marked, and the figure will be thus completed. 6) This line is taken from the corner of the front edge to the opposite point of the measurement, showing how exactly either this line, o that marked 4, will give the perspective width of the square. It serves also to find the centre.

Parallel Perspective

The perspective shown in this plate is parallel perspective; and the subject here intended to be represented…

The perspective in this plate is "angular perspective," and the figure it represents is a flat square surface; its dimensions are supposed to be either twenty feet or twenty inches. 1) Two lines drawn from the nearest corner of theboard, to the horizontal line, and at a distance from each other equal to the thickness of the board; this fixes the vanishing point at 1. 2) A line drawn from the above vanishing point to the point of station. 3) A line taken at right angles to 2, from the point of station, and fixing on the horizontal line the position of the vanishing point 3. 4) Two lines drawn from the nearest corner of the board to the vanishing point 3, similarly to the previously drawn lines 1. 5) One point of measurement, obtained in the usual way, by the distance of 3 from the point of station. 6) The point of measurement. 7) The line of the geometrical scale, being a line drawn across the base of the nearest corner, and marked according to scale, twenty feet or twenty inches. 8,8) Lines taken from either end of the geometrical scale towards the point of measurement, but extending no farther than where they meet the lines 1,1, and 4,4. 9,10) Small perpendicular lines drawn at the above intersections, by which the width of the board is ascertained. 11) The side of the board opposite and really parallel to that marked 4, and therefore tending to the same vanishing point. 12) The back of the board, opposite and parallel to the front marked 1, and consequently tending to the same vanishing point. The lines 1,1; 4,4; 11 and 12, being strongly marked, the figure will be completed.

Angular Perspective

The perspective in this plate is "angular perspective," and the figure it represents is a flat square…

Two upright oblong figures are here represented in parallel perspective. They may be imagined to resemble the sides and fronts of houses, or their blank walls. One of the figures has two others attached to it of equal dimensions; and these additions might be similarly multiplied to any extent, by the numbers, 7, 8, 9 and 10, in the followig rules. 1) Lines forming to complete fronts of two separate and detached oblongs. 2) The geometrical scale at the base, marked twenty feet. 3) The ground lines of the fronts running to the vanishing point. 4) The top lines tending to vanishing point. 5) Lines from the geometrical scale, to the points of measurement, determining the perspective depths of the oblongs. 6) Perpendicular lines raised at the intersection of the lines 3 and 5, and giving the farthest upright corner lines of the oblongs. The two figures will thus be completed. The remaining lines inserted in the figure are intended to give two other oblongs (or rather their retiring sides) attached to the first, and supposed to be of the same dimensions. They are determined first by finding the centre 7 of the near corner line 1. From 7 a line is drawn to the vanishing point. A line marked 8 is then drawn from the near extremity of 1 through 6, where it is cut by 7; at its intersection with the bottom line 3, the perpendicular line 9 is raised, and another oblong front is completed. A line 10 is drawn, and determined as the line 8 was, from the top of 6, and by crossing the lines 7 and 3. The lines 13, 14, and 15, are inserted merely to show the inner side and back of the other oblong, as they would be seen were the object made of glass. Thus 13,13 are lines for the top and bottom of the back; formed by drawing them to the vanishing point; 14,14 are the top and bottom lines of the farthest side, found by straight lines being drawn from both ends of , until they meet 13,13; at which point of meeting the upright corner of the oblong are completed.

Parallel Perspective

Two upright oblong figures are here represented in parallel perspective. They may be imagined to resemble…

This object is a cube, having therefore all its faces of equal dimensions; and as both sides recede, "angular perspective" is employed. The point of sight, horizontal line, and point of station, having been fixed upon, the line A is first to be drawn, touching the bottom of the nearest corner, and is for the geometrical scale or height of the cube, which, in this instance, will be called twelve feet; that is, twelve feet must be marked on the scale from the corner on either side. 1) The ground line of the square, taken from the centre of the geometrical scale line to the horizontal line; by its junction with which is determined the vanishing point or that side. 2) A line drawn from the above vanishing point to the point of station. 3) A line drawn at right angles at the point of station to the line 2, as far as the horizontal line, its intersection with which will give the correct vanishing point to the other side. 4) The ground line of the cube running to the last vanishing point. 5) The nearest corner of the cube, twelve feet in height, being equal to the width. The points of measurement are next to be ascertained, and to be marked in the usual way; and the lines B drawn from the ends of the geometrical scale towards the point of measurement give the perspective width or depth of both sides. This is found at their cutting of the ground lines 1 and 4. The line 6 represents the top line of one side of the cube, and runs from the nearest corner to the vanishing point. 7) The other top line; and it is drawn to the other vanishing point. 8) The far corner line raised vertically from the crossing of the lines B and 1. 9) The other corner line raised vertically from the intersection of the lines B and 4. The lines 1, 4, 5, 6, 7, 8, 9, being strengthened, the figure is complete.

Angular Perspective

This object is a cube, having therefore all its faces of equal dimensions; and as both sides recede,…

This cube has four additional cubes of equal dimensions. This is effected by first drawing the cube in the order and then finding the centre of the upright line 5, that being the nearest corner line of this first cube. The centre being found at 10, take the line 10 to the vanishing point for that side of the cube; this will give the centres of all the other upright lines of that side of all the added cubes. The line 11 is drawn from the top of the corner line 5, through the intersection of 8 and 10, until it meets the ground line 1, at its junction with which the upright line is raised for the far corner line 12 of the second cube. The three other cubes are described precisely in the same manner, being found by the diagonal lines traversing each pair of the cubes, through the intersection of the centre line 10, with each perpendicular line raised from the meeting of the previous diagonal line with the ground line 1. It will be perceived that a further distance of twelve feet is added to one side of the geometrical scale, and marked A. This is done merely to prove the correctness of the first diagonal line 11, passing through the centre line 10, to determine the perspective depth of the second cube. For if a line be taken from the end of the geometrical scale A to the point of measurement on the horizontal line, it will be found to meet the ground line 1 at exactly the same point; thus proving the truth of both modes of drawing. The former mode, however, is more convenient where a number of cubes are to be drawn; as the geometrical scale might extend far beyond the limits of the paper, and consequently give much more trouble.

Angular Perspective

This cube has four additional cubes of equal dimensions. This is effected by first drawing the cube…

This figure differs from the others because they are solid cubes. Further, the geometrical scale is used for the two cubes, because, being only two, it will be found in this way that fewer lines will be necessary, leaving the figure less intricate and confused. The two frnt sides of the cubes are produced in the same way as far as line 10, which is the farthest corner line of the second cube. 11) The line is drawn from the extremity of 10 to the vanishing point of 7, the two lines being really parallel. 12) Is drawn from the top of 9 to the vanishing point of line 6, these also being parallel. 13) Is drawn from the top of the upright centre line 8, to the vanishing point of 11 and 7, these being all really parallel to each other. 14) Is the far ground line taken from the lower extremity of 9 to the vanishing point of 1, these lines being also parallel. 15 and 16) Are lines drawn from the corner end of 10 and 8 to the vanishing point of 4, the three lines being really parallel. 17 and 18) Are upright lines raised at the intersection of the lines 16 and 15, with the ground line 14, being the far corners of the cubes; they respectively will meet the intersections of lines 11 and 13 with 12. These lines will complete the figure.

Angular Perspective

This figure differs from the others because they are solid cubes. Further, the geometrical scale is…

"A landscape is supposed to be viewed from the spot marked E; and that the spectator is desirous of representing on the plane of his paper a certain portion of the scene as seen by him fom this point. That portion constitutes his real picture. The distance of this picture,- or distance of the eye from the plane of the picture (which is the same thing), -means the distance intervening between the spectator's position, and that point on the ground directly in front of him, where the picture, which he is about to make, ought properly to commence. Upon the choice of a proper and judicious distance the beauty of his work will in a great measure depend. Suppose the landscape to be viewed from the point E, then that portion of the scene which the eye can easily take in, without moving the head, and without the slightest strain upon the optic nerve, will constitute the picture from that point. Now, under this condition the spectator will find that he does not distinctly see the ground immediately before him, but that he obtains a perfectly easy view of it only at some distance from his position at E. It is the space included between the point E (where he is placed), and the supposed point alluded to, and here marked S, that establishes the required distance of the picture, that is, the distance of the eye from the proposed picture. For instance, let S be that point on the ground immediately in front of the eye, and if through S a straight line be supposed to be drawn, perpendicular to the distance ES, this line will pass through and determine the foremost objects of the proposed picture, and therefore at this line the picture must commence."

Distance

"A landscape is supposed to be viewed from the spot marked E; and that the spectator is desirous of…

That an accurate notion of the vertical line may be obtained, the plane of the picture must be supposed to be perpendicular to the horizontal plane. If a straight line be drawn from the spectator's eye, perpendicular to this plane of the picture, that line will fall upon the plane at a point in the horizontal line directly opposite to the eye. This point, C, is called the centre of the picture, or centre of view. In reference to the eye of the spectator, every straight line perpendicular to the plane of the picture appears to converge towards this point or centre. The line which, drawn from the eye of the spectator, determines this centre C, is called the vertical line. It is a straight line through S, perpendicular to the horizontal line, and the base of the picture; and is represented by the line EC.

Vertical Line

That an accurate notion of the vertical line may be obtained, the plane of the picture must be supposed…

When Henry VIII became king in 1509, Wolsey's affairs prospered. He became Canon of Windsor, Berkshire in 1511, the same year in which he became a member of the Privy Council. His political star was in the ascendant, and he soon became the controlling figure in all matters of state. 1514, he was made Bishop of Lincoln, and then Archbishop of York.

Cardinal Wolsey Served by Noblemen

When Henry VIII became king in 1509, Wolsey's affairs prospered. He became Canon of Windsor, Berkshire…

Magnified section through the thickness of a leaf of Florida Star-Anise.

Florida Star-Anise

Magnified section through the thickness of a leaf of Florida Star-Anise.

A spring is a point where groundwater flows from the ground, and is thus where the aquifer surface meets the ground surface

Origin of Springs

A spring is a point where groundwater flows from the ground, and is thus where the aquifer surface meets…

One of the greatest of the Girondists, was born at Marseilles, March 6, 1767. At first an advocate and journalist at Marseilles, he was sent by that city to the Constituent Assembly at Paris. There he opposed the Court party, and took part with the Minister, Roland, then out of favor. After the events of the 10th of August, 1792, he returned to his native town, where he was received with enthusiasm, and was soon after chosen delegate to the Convention. In the Convention he adhered to the Girondists, and belonged to the party who, at the trial of the King, voted for an appeal to the people. He boldly opposed the party of Marat and Robespierre, and even directly accused the latter of aiming at the dictatorship; consequently, he was, in May, 1793, proscribed as a royalist and enemy of the Republic. He fled to Calvados, and thence with a few friends to the Gironde, where he wandered about country, hiding himself as he best could for about 13 months. At last, on the point of being taken, he tried to shoot himself; but the shot miscarried, and he was guillotined at Bordeaux, June 25, 1794. This "brave and beautiful young Spartan" was one of the great spirits of the Revolution. There was no loftier-minded dreamer in the Girondist ranks; hardly a nobler head than his fell in that reign of terror. He was "ripe in energy, not ripe in wisdom," says Carlyle, or the history of France might have been different.

Charles Jean Marie Barbaroux

One of the greatest of the Girondists, was born at Marseilles, March 6, 1767. At first an advocate and…

Section through the thickness of a leaf of Florida Star-Anise.

Florida Star-Anise

Section through the thickness of a leaf of Florida Star-Anise.

Gall made by the larva of Cynips q. spongifica. a, larve in its cell; b, point of exit of adult.

Cynips Spongifica

Gall made by the larva of Cynips q. spongifica. a, larve in its cell; b, point of exit of adult.

Any four-point on a curve of the second order and the four-side formed by the tangents at these points stand in this relation that the diagonal points of the four-point lie in the diagonals of the four-side.

Second Order Curve Tangents

Any four-point on a curve of the second order and the four-side formed by the tangents at these points…

The three points in which any line cuts the sides of a triangle and the projections, from any point in the plane, of the vertices of the triangle on to the same line are six points in involution.

Involution

The three points in which any line cuts the sides of a triangle and the projections, from any point…

The lines which join corresponding points in an involution on a conic all pass through a fixed point; and reciprocally, the points of intersection of conjugate lines in an involution among tangents to a conic lie on a line.

Conic Involution

The lines which join corresponding points in an involution on a conic all pass through a fixed point;…

The lines joining any point on a conic to the two foci are equally inclined to the tangent and normal at that point. This is an ellipse.

Conic Foci Involution

The lines joining any point on a conic to the two foci are equally inclined to the tangent and normal…

The segments between the point of intersection of two tangents to a conic and their points of contact are seen from a focus under equal angles. the ratio of the distances of any point on a conic from a focus and the corresponding directrix is constant.

Parabola Foci Properties

The segments between the point of intersection of two tangents to a conic and their points of contact…

Two planes lie perpendicular to one another. A line perpendicular to plane 1 and a line perpendicular to plane 2 will meet at a point, A, and form a perpendicular intersection.

Perpendicular Planes

Two planes lie perpendicular to one another. A line perpendicular to plane 1 and a line perpendicular…

A point lies in the first quadrant if the plan lies below, the elevation above the axis; in the second if plan and elevation both lie above; in the third if the plan lies above, the elevation below; in the the fourth if plan and elevation both lie below the axis.

Quadrants

A point lies in the first quadrant if the plan lies below, the elevation above the axis; in the second…

To find the projections of a line which joins two points, A, B given by their projections.

Line Projection

To find the projections of a line which joins two points, A, B given by their projections.

To draw a plane through a given point parallel to a given plane.

Parallel Planes

To draw a plane through a given point parallel to a given plane.

To determine the distance between two points A, B given by their projections.

Point Distance

To determine the distance between two points A, B given by their projections.

Intersection of lines between a circle and its polar point.

Circle Polar Point

Intersection of lines between a circle and its polar point.

Given any three circles, the common chords meet at one point.

Radical Center of 3 Circles

Given any three circles, the common chords meet at one point.

Illustration 1 of the Dedekind axiom.

Dedekind Property 1

Illustration 1 of the Dedekind axiom.

Illustration 2 of the Dedekind axiom.

Dedekind Property 2

Illustration 2 of the Dedekind axiom.

Illustration 3 of the Dedekind axiom.

Dedekind Property 3

Illustration 3 of the Dedekind axiom.

Illustration 4 of the Dedekind axiom.

Dedekind Property 4

Illustration 4 of the Dedekind axiom.

Theory of static equilibrium of mechanism, illustrated b Sir A.B.W. Kennedy.

Wheel Mechanism

Theory of static equilibrium of mechanism, illustrated b Sir A.B.W. Kennedy.

An instrument for making a reduced, enlarged, or exact copy of a plane figure

Pantograph

An instrument for making a reduced, enlarged, or exact copy of a plane figure

"A bent tube with one limb longer than the other, by means of which a liquid can be drawn off to a lower level over the side of a vessel or other point higher than the upper surface of the liquid."—Finley, 1917

Siphon

"A bent tube with one limb longer than the other, by means of which a liquid can be drawn off to a lower…

Prehistoric Irish spearheads, made of bronze.

Prehistoric Irish spearheads

Prehistoric Irish spearheads, made of bronze.

Prehistoric British spearheads.

Prehistoric British spearheads

Prehistoric British spearheads.

Medieval spearheads.

Medieval spearhead

Medieval spearheads.

A Phillipine spearhead.

Phillipine spearhead

A Phillipine spearhead.

"Star of Bethlehem, or Ornithogalum, a genus of bulbous plants belonging to the order Liliacae."—Finley, 1917

Star of Bethlehem

"Star of Bethlehem, or Ornithogalum, a genus of bulbous plants belonging to the order Liliacae."—Finley,…

Pistil of a Star of Bethlehem.

Star of Bethlehem, pistil of

Pistil of a Star of Bethlehem.

Stamen of a Star of Bethlehem.

Stamen of Star of Bethlehem

Stamen of a Star of Bethlehem.

Shows the differences between the Centigrade and absolute (Kelvin) temperature scales at the boiling point of water, room temperature, freezing point of water, boiling point of hydrogen and absolute zero.

Temperature Scales

Shows the differences between the Centigrade and absolute (Kelvin) temperature scales at the boiling…

"In the manufacture of artificial ice, ammonia is liquefied by being compressed by powerful pumps; then the liquid ammonia is cooled by passing cold water over the pipes containing it. the liquid ammonia is distributed through pipes, where it evaporates rapidly. The gas is drawn back by the pump, condensed to a liquid, and used again. The pipes in which the evaporation takes place are immersed in a strong salt solution, which, by furnishing heat for evaporation, is cooled to a point below the freezing-point of water." -Brownlee 1907

Refrigerating Plant

"In the manufacture of artificial ice, ammonia is liquefied by being compressed by powerful pumps; then…

Regions of the abdomen and their contents (edge of costal cartilages in dotted outline). "For convenience of description the abdomen may be artificially divided into nine regions by drawing two circular lines around the body parallel with the cartilages of the ninth ribs, and the highest point of the crests of the ilia; and two vertical lines from the cartilage of the eighth rib on each side to the center of Poupart's ligament. The vicar contained in these different regions are as follows: -- Right Hypochondriac - the right lobe of the liver and gall-bladder, hepatic flexure of the colon, and part of the right kidney. Right Lumbar - ascending colon, part of the right kidney, and some convolutions of the small intestines. Right Inguinal (Iliac) - the caecum, appendix caeci. Epigastric Region - the middle and pyloric end o the stomach, left lobe of the liver, the pancreas, the duodenum, part of the kidneys and the suprarenal capsules. Umbilical Region - the transverse colon, part of the great omentum and mesentery, transverse part of the duodenum, and some convolutions of the jejunum and ileum, and part of both kidneys. Hypogastric Region - convolutions of the small intestines, the bladder in children, and in adults if distended, and the uterus during pregnancy. Left Hypochondriac - the splenic end of the stomach, the spleen and extremity of the pancreas, the splenic flexure of the colon, and part of the left kidney. Left Lumbar - descending color, part of the omentum, part of the left kidney, and some convolutions of the small intestines. Left Inguinal (Iliac) - sigmoid flexure of the colon." — Kimber, 1907.

Regions of the Abdomen and their Contents

Regions of the abdomen and their contents (edge of costal cartilages in dotted outline). "For convenience…