The obverse and reverse sides of the Denarius, a Roman coin. The coin depicts Gaius Claudius Marcellus Minor.

Denarius of Marcellus

The obverse and reverse sides of the Denarius, a Roman coin. The coin depicts Gaius Claudius Marcellus…

An illustration of the reverse side of a U.S. Dime.

Back of a Dime

An illustration of the reverse side of a U.S. Dime.

An illustration of the reverse side of a U.S. Dollar.

Back of a Dollar

An illustration of the reverse side of a U.S. Dollar.

The obverse and reverse sides of the fanam, a small silver coin used in Madras, India.

Obverse and Reverse Sides of Fanam of Madras

The obverse and reverse sides of the fanam, a small silver coin used in Madras, India.

A reverse fault is the opposite of a normal fault — the hanging wall moves up relative to the footwall. Reverse faults are indicative of shortening of the crust. The dip of a reverse fault is relatively steep, greater than 45°.

Reverse Fault

A reverse fault is the opposite of a normal fault — the hanging wall moves up relative to the…

"The English name of a gold coin weighing about 55 grains, first issued at Florence in 1252, and having on the obverse a lily and the word 'Florentia.'" -Whitney, 1911

Obverse and Reverse Sides of Gold Florin

"The English name of a gold coin weighing about 55 grains, first issued at Florence in 1252, and having…

"A French silver coin and money of account which since 1795 has formed the unit of French monetary system." -Whitney, 1911

Reverse Side of Silver Franc of Henry III

"A French silver coin and money of account which since 1795 has formed the unit of French monetary system."…

"Under Louis XV, and Louis XVI, the sou was struck in copper, and had an intrinsic value of two deniers twelve grains, though retaining the conventional value of twelve deniers, and this coinage continued until the adoption of the existing decimal system in 1793." —Whitney, 1889
<p>This illustration shows the reverse of the coin, on which is displayed an oak wreath with a scale.

French Sou from 1793, Reverse

"Under Louis XV, and Louis XVI, the sou was struck in copper, and had an intrinsic value of two deniers…

"Gazzetta of the Ionian islands, 1801. A small copper coin, worth about 3 farthings, made in Venice for the Ionian islands." -Whitney, 1911

Obverse and Reverse Sides of a Gazzetta

"Gazzetta of the Ionian islands, 1801. A small copper coin, worth about 3 farthings, made in Venice…

"In the reign of Philip of Macedon, the coinage of Greece had attained its full development, having a perfect reverse. One of the earliest specimens of the complete coin is a beautiful medal struck at Syracuse, with the head of Proserpine accompanied by dolphins, and for reverse a victor in the Olympic games in a chariot receiving a wreath from Victory-a type which is also found on the reverse of the staters of Philip of Macedon, known as Philips, and largely imitated by other states." &mdash; Chambers, 1881

Greek Coin

"In the reign of Philip of Macedon, the coinage of Greece had attained its full development, having…

"Gros Tournois of Louis IX. GROS. A coin of relatively large size: applied to silver coins of various kinds in France in the thirteenth and following centuries." -Whitney, 1911

Reverse Side of Gros Tornois

"Gros Tournois of Louis IX. GROS. A coin of relatively large size: applied to silver coins of various…

"Guinea of Charles II., 1663. GUINEA. An English gold coin, of the value of 21 shillings, first issued by Charles II. in 1663, and by his successors till 1813, since which year it has not been coined." -Whitney, 1911

Guinea

"Guinea of Charles II., 1663. GUINEA. An English gold coin, of the value of 21 shillings, first issued…

"Silver gulden of William III., King of the Netherlands, 1867. GULDEN. One of several gold coins in Germany from the fourteenth century ... the name was afterward applied to silver coins of Germany and the Netherlands." -Whitney, 1911

Gulden

"Silver gulden of William III., King of the Netherlands, 1867. GULDEN. One of several gold coins in…

An illustration of the reverse side of a U.S. Half Dollar.

Back of a Half Dollar

An illustration of the reverse side of a U.S. Half Dollar.

An illustration of the reverse side of a U.S. nickel.

Back of a Nickel

An illustration of the reverse side of a U.S. nickel.

An illustration of the reverse side of a U.S. Penny.

Back of a Penny

An illustration of the reverse side of a U.S. Penny.

"Reversing rod inside hollow propeller shaft: by twisting the blades round, the motion of the boat is reversed without changing the rotation of the screw."&mdash;Finley, 1917

Reversible propeller

"Reversing rod inside hollow propeller shaft: by twisting the blades round, the motion of the boat is…

An illustration of the reverse side of a U.S. Quarter.

Back of a Quarter

An illustration of the reverse side of a U.S. Quarter.

The coin (front) bears the image of the Virgin Mary receiving Gabriel's salutation. The back of the coin is decorated with a Christian cross. It was issued by Charles VI of France and by Henry V and Henry VI of England. It weighs approximately 54 grains.

Salute, a Golden Coin (Reverse)

The coin (front) bears the image of the Virgin Mary receiving Gabriel's salutation. The back of the…

"A money formerly used in Scandinavia and northern Germany, in some places as a coin and in others as a money of account. It varied in value from 1/4d. in Denmark to nearly 1d. (about 2 cents) in Hamburg."
<p>This illustration is of the back of the copper coin and features two crossed arrows.

Skilling Coin - Reverse

"A money formerly used in Scandinavia and northern Germany, in some places as a coin and in others as…

"A guinea coined by George III during the period 1787-99. It is now so called because the shield of arms on the reverse has the shape of the spade of playing cards." &mdash;Whitney, 1889

Spade Guinea Coined by George III, Reverse

"A guinea coined by George III during the period 1787-99. It is now so called because the shield of…