An Hourglass measures the passage of few minutes or an hour of time.
It has two connected vertical glass bulbs allowing a regulated trickle of
material from the top the bottom. Once the top bulb is empty, it can be
inverted to begin timing again.
It has two connected vertical glass bulbs allowing a regulated trickle of
material from the top the bottom. Once the top bulb is empty, it can be
inverted to begin timing again.
History
The origin of hourglass is unclear, the first referenced used
1) According to the American Institute of New York:
The sand Glass was invented at Alexandria about 150 BC.
2) According to the journal of British Archaeological Association:
Hourglass were in use before the time of St. Jerome and the first representation
of an hourglass it is in a Sarcophagus dated 340 AD ,
representing the wedding of Peleus and Thetis,
discovered in home in the 18th century.
The hourglass has also been called a “sand clock“. It works on the same principle as the clepsydra With clepsydra (AKA water clocks), water moves from one vessel to another or leaks out of a vessel at a precise rate. How much water is present in a second vessel or remaining in the only vessel indicates the time depending upon the design of the clock. Water clocks date as far back as 1500BC.
Some people date “sand clocks” to 1300AD when requests for hourglasses started showing up on shopping lists for ships. The hourglass was important for shipping. Water clocks and pendulum clocks aren't reliable on ships because they need to be stable to keep time accurately. Hourglasses can be suspended from a hook and the swaying of a ship doesn't interfere very much with the movement of the sand. Additional support for the hourglass being invented in the 1300s is that an hourglass is featured in Lorenzetti’s work “Allegory of Good Government” which was created in 1338. Some people say this is the earliest artistic representation of an hourglass. That puts the hourglass being invented at the same time as the mechanical clock and that doesn't pass the sniff test.
Ancient Egyptians, ancient Greeks, and ancient Romans, all had the technology, knowledge, and supplies needed to create a sand clock. The idea that technology seemed to stand still from 1500BC to 1300AD just doesn't make sense to us.
According to Knight's American Mechanical Dictionary(copyright 1817): “The sand-glass was derived from or suggested by the clepsydra.” The dictionary goes on to say, “On an ancient bas-relief in Rome an hour-glass is placed in the hands of Morpheus. Athenaeus says that the ancients carried portable hour-glasses with them.”
Charles Dickens (yes, the Charles Dickens) made note of the same depiction of Morpheus in the which an hourglass can be seen in his nonfiction weekly journal, “All the Year Round” (volume number: X; copyright 1873). “No one knows at what period these time treasures were introduced. In a basso-relievo at Mattei Palace, presenting the marriage of Thetis and Peleus, Morpheus appears holding an hour-glass in his hand. This shows, at any rate, such implements were known in mythological days of Greece.”
That’s good enough for me. Far be it for me to argue with Charles Dickens, one of my researchers, however, will argue with Charles Dickens. She’s like a hunting dog when it comes to sniffing out information and she won’t let up until she’s satisfied.
According to her logic, an artistic depiction of an event isn't evidence of technological levels at the time of the event. It’s evidence of technological levels at the time of the creation of the artwork. We set out to date the basso-relievo and came up empty handed. We tried to date the Mattei Palace and came across a tidbit of information that puts the palace construction around 1191. We’re unsure of the accuracy of that date. The famous “turtle fountain” on the grounds of the Mattei Palace dates back to the 1500s. The turtles themselves weren't added until the 1600s. The idea was to date the wall that held the bas-relief, but that turned into another dead end.
Numerous horological websites state that the hourglass dates back to ancient times. We know that ancient societies used oil lamps, candles, as well as clepsydra to mark time. It stands to reason that they would also use sand. Some history websites mention that hourglasses were used to time Senator’s speeches in ancient Rome. The book “Ancient Inventions” states that the Senators used clepsydra for that purpose not sand-based timepieces. The Senators would use a wax plug to temporarily pause the “clock” when their speeches were interrupted. Sand would cling to such a plug and with several uses the accuracy of the hourglass would be questionable.
By the 1300s hourglasses were so common that they were a staple on ships and were used symbolically in artwork. It takes time for a symbol to seep into culture and to be used symbolically. The symbolism of the hourglass seems to span several different cultures. That would also take a lot of time. We can’t point to any definitive piece of evidence, but 1300 seems way too late for the creation of the hourglass.
The hourglass is a technological equivalent of the ancient water clocks and we believe they date back that far.
1) According to the American Institute of New York:
The sand Glass was invented at Alexandria about 150 BC.
2) According to the journal of British Archaeological Association:
Hourglass were in use before the time of St. Jerome and the first representation
of an hourglass it is in a Sarcophagus dated 340 AD ,
representing the wedding of Peleus and Thetis,
discovered in home in the 18th century.
The hourglass has also been called a “sand clock“. It works on the same principle as the clepsydra With clepsydra (AKA water clocks), water moves from one vessel to another or leaks out of a vessel at a precise rate. How much water is present in a second vessel or remaining in the only vessel indicates the time depending upon the design of the clock. Water clocks date as far back as 1500BC.
Some people date “sand clocks” to 1300AD when requests for hourglasses started showing up on shopping lists for ships. The hourglass was important for shipping. Water clocks and pendulum clocks aren't reliable on ships because they need to be stable to keep time accurately. Hourglasses can be suspended from a hook and the swaying of a ship doesn't interfere very much with the movement of the sand. Additional support for the hourglass being invented in the 1300s is that an hourglass is featured in Lorenzetti’s work “Allegory of Good Government” which was created in 1338. Some people say this is the earliest artistic representation of an hourglass. That puts the hourglass being invented at the same time as the mechanical clock and that doesn't pass the sniff test.
Ancient Egyptians, ancient Greeks, and ancient Romans, all had the technology, knowledge, and supplies needed to create a sand clock. The idea that technology seemed to stand still from 1500BC to 1300AD just doesn't make sense to us.
According to Knight's American Mechanical Dictionary(copyright 1817): “The sand-glass was derived from or suggested by the clepsydra.” The dictionary goes on to say, “On an ancient bas-relief in Rome an hour-glass is placed in the hands of Morpheus. Athenaeus says that the ancients carried portable hour-glasses with them.”
Charles Dickens (yes, the Charles Dickens) made note of the same depiction of Morpheus in the which an hourglass can be seen in his nonfiction weekly journal, “All the Year Round” (volume number: X; copyright 1873). “No one knows at what period these time treasures were introduced. In a basso-relievo at Mattei Palace, presenting the marriage of Thetis and Peleus, Morpheus appears holding an hour-glass in his hand. This shows, at any rate, such implements were known in mythological days of Greece.”
That’s good enough for me. Far be it for me to argue with Charles Dickens, one of my researchers, however, will argue with Charles Dickens. She’s like a hunting dog when it comes to sniffing out information and she won’t let up until she’s satisfied.
According to her logic, an artistic depiction of an event isn't evidence of technological levels at the time of the event. It’s evidence of technological levels at the time of the creation of the artwork. We set out to date the basso-relievo and came up empty handed. We tried to date the Mattei Palace and came across a tidbit of information that puts the palace construction around 1191. We’re unsure of the accuracy of that date. The famous “turtle fountain” on the grounds of the Mattei Palace dates back to the 1500s. The turtles themselves weren't added until the 1600s. The idea was to date the wall that held the bas-relief, but that turned into another dead end.
Numerous horological websites state that the hourglass dates back to ancient times. We know that ancient societies used oil lamps, candles, as well as clepsydra to mark time. It stands to reason that they would also use sand. Some history websites mention that hourglasses were used to time Senator’s speeches in ancient Rome. The book “Ancient Inventions” states that the Senators used clepsydra for that purpose not sand-based timepieces. The Senators would use a wax plug to temporarily pause the “clock” when their speeches were interrupted. Sand would cling to such a plug and with several uses the accuracy of the hourglass would be questionable.
By the 1300s hourglasses were so common that they were a staple on ships and were used symbolically in artwork. It takes time for a symbol to seep into culture and to be used symbolically. The symbolism of the hourglass seems to span several different cultures. That would also take a lot of time. We can’t point to any definitive piece of evidence, but 1300 seems way too late for the creation of the hourglass.
The hourglass is a technological equivalent of the ancient water clocks and we believe they date back that far.
Design
Design and conceptualization are usually the most complicated part of hourglass making. The hourglass maker must be craftsman, artist, and public relations expert in advising clients of the practicalities in hourglass design and construction. Businesses are commissioning hourglasses as gifts related to the year 2000, but they also want to reflect the character of their business or incorporate materials associated with their products. After the design is finalized, actual construction of the hourglass is relatively straightforward.
Sand-clock designs can also vary considerably in size. The smallest known hourglasses are the size of a cuff link, and the largest are up to 3 ft (1 m) tall. The glasses can have various shapes from round to oblong and can be engraved. Multiple (more than two) glass gloves can be linked together, and several hourglasses can be mounted in the same frame and turned on a turnstile.
According to one craftsman, hourglass design has no limits. He develops his own designs, makes hourglasses based on designs or requests provided by his customers, or creates designs to suit a particular market interest. He has sculpted pairs of his own hands as frames to hold the glasses, used unusual materials like bamboo or marble to craft the frames, and called on other hourglasses, such as the gargoyle-framed hourglass in the movie version of The Wizard of Oz, for his inspirations. He has made hourglasses containing coal sand, mining slag, sand from the Great Wall of China, and polyethylene resin sand. Shopping networks on television are currently selling hourglasses that are futuristic in design in keeping with interest in the new millennium.
The Manufacturing
Process
The first hourglass were two separate bulbs with a cord wrapped at their union that was then coated in was to hold the piece together and let sand flow in between.
Sand-clock designs can also vary considerably in size. The smallest known hourglasses are the size of a cuff link, and the largest are up to 3 ft (1 m) tall. The glasses can have various shapes from round to oblong and can be engraved. Multiple (more than two) glass gloves can be linked together, and several hourglasses can be mounted in the same frame and turned on a turnstile.
According to one craftsman, hourglass design has no limits. He develops his own designs, makes hourglasses based on designs or requests provided by his customers, or creates designs to suit a particular market interest. He has sculpted pairs of his own hands as frames to hold the glasses, used unusual materials like bamboo or marble to craft the frames, and called on other hourglasses, such as the gargoyle-framed hourglass in the movie version of The Wizard of Oz, for his inspirations. He has made hourglasses containing coal sand, mining slag, sand from the Great Wall of China, and polyethylene resin sand. Shopping networks on television are currently selling hourglasses that are futuristic in design in keeping with interest in the new millennium.
The Manufacturing
Process
- After the design and materials are selected, the body of the hourglass is blown on a glass lathe to a size appropriate for the size (time interval) of the hourglass.
- The frame is made; depending on its design, it may be a single piece or multiple pieces including a bottom, top, and three or four posts. This manufacture depends on the material. If the frame is made of resin, molds may be constructed, the resin is poured in and allowed to cure, the pieces are sanded or otherwise smoothed and polished, and they are fitted together. Frame pieces may be fitted to interlock; or they may be glued, bonded, or welded, again depending on the materials involved.
- One of the most common misconceptions about hourglasses is that there is a formula for the quantity of sand contained in the glass. The sand quantity in a given hourglass design or shape is not based on science or a measurement formula. The types of grains, the curves of the glass, and the shape and size of the opening impose too many variables on the rate of flow of the sand through the glass, so the amount of sand can not be mathematically calculated. Before the top of the frame is sealed, sand is added and allowed to flow through the glass for its prescribed time interval. At the end of that time period, sand remaining in the top of the glass is poured off and the glass is sealed.
The first hourglass were two separate bulbs with a cord wrapped at their union that was then coated in was to hold the piece together and let sand flow in between.
Material
Glass for hourglasses is the same material as that used for other blown glass. It is manufactured in tubes of varying lengths by specialized suppliers for firing and shaping by machine or by mouth-blowing. Pre-formed light-bulb blanks can also be transformed into hourglasses by joining them together at the bases of the bulbs. Similarly, jars can be hooked together at their necks to make hourglasses; these can range in appearance from rustic to modern depending on the "character" of the jars.
The frames or housings for hourglasses are open to the designer's whims. Raw materials most often consist of pieces of fine wood that can be crafted or carved to suit a particular style, decor, design, or theme. Bamboo, resin, and various metals like brass, bronze, and pewter are also beautiful framing materials. Specialized hourglasses are made in such small numbers that raw materials are purchased from outside sources for limited
The sand used in a decent hourglass isn't regular sand. Sometimes it’s not even sand. Typically, sand is too angular to pass evenly through the neck of an hourglass. Angular sand will also wear away at the glass and slowly widen the neck which results in an inaccurate timepiece. Polished, dried, and rounded sand is sometimes used. Powdered marble and silica is sometimes used also. A few sand-glasses actually contain tiny glass beads or shot instead of sand.
Earlier some hourglass actually did use sand as the granular mixture to measure time,
many did not use sand at all. The material used in most bulbs was a combination of
"powdered marble, tin/lead oxides, and burnt egg shells".
The frames or housings for hourglasses are open to the designer's whims. Raw materials most often consist of pieces of fine wood that can be crafted or carved to suit a particular style, decor, design, or theme. Bamboo, resin, and various metals like brass, bronze, and pewter are also beautiful framing materials. Specialized hourglasses are made in such small numbers that raw materials are purchased from outside sources for limited
The sand used in a decent hourglass isn't regular sand. Sometimes it’s not even sand. Typically, sand is too angular to pass evenly through the neck of an hourglass. Angular sand will also wear away at the glass and slowly widen the neck which results in an inaccurate timepiece. Polished, dried, and rounded sand is sometimes used. Powdered marble and silica is sometimes used also. A few sand-glasses actually contain tiny glass beads or shot instead of sand.
Earlier some hourglass actually did use sand as the granular mixture to measure time,
many did not use sand at all. The material used in most bulbs was a combination of
"powdered marble, tin/lead oxides, and burnt egg shells".
Uses
Hourglasses, like this old one made out of bronze, were frequently used on sailing vessels.
Some hourglasses were quite elaborate and fit the name “sand clock” better than “hourglass”. Some sand clocks were a series of hourglasses that could be flipped independently. Some would mark the quarter and half hour while others would mark a whole hour or two hours. As previously mentioned, hourglasses were used on ships to help mark the passage of time while at sea. Sailors and pirates used hourglasses in a few different ways. One way was the “watch glass“. This was an hourglass that would sound a bell every half an hour so that the crew could keep track of time. Sailors also figured out how to determine their speed with an hourglass. A knotted piece of rope with a woodchip attached at the end would float out from the stern of the ship. An officer would use a small sand clock to mark time between the knots (between 15 and 30 seconds depending upon the culture). This is the origin of the nautical term “knots” as in “knots per hour”.
Some hourglasses are called “pulpit glasses“. These were hourglasses (some measured two hours) that were kept at the lectern of the sanctuary. When the priest would deliver their homily or the pastor would deliver their sermon, the hourglass helped prevent anyone from becoming verbose.
Some people still use hourglasses for games and as egg timers in the kitchen. But the steampunk craze is bringing back the aesthetics of yore and hourglasses are experiencing an uptick of popularity within that subculture. They’re also often used symbolically in artwork and media presentations. The “wait” icon in some computer operating systems is a symbolic use of an hourglass
Some hourglasses were quite elaborate and fit the name “sand clock” better than “hourglass”. Some sand clocks were a series of hourglasses that could be flipped independently. Some would mark the quarter and half hour while others would mark a whole hour or two hours. As previously mentioned, hourglasses were used on ships to help mark the passage of time while at sea. Sailors and pirates used hourglasses in a few different ways. One way was the “watch glass“. This was an hourglass that would sound a bell every half an hour so that the crew could keep track of time. Sailors also figured out how to determine their speed with an hourglass. A knotted piece of rope with a woodchip attached at the end would float out from the stern of the ship. An officer would use a small sand clock to mark time between the knots (between 15 and 30 seconds depending upon the culture). This is the origin of the nautical term “knots” as in “knots per hour”.
Some hourglasses are called “pulpit glasses“. These were hourglasses (some measured two hours) that were kept at the lectern of the sanctuary. When the priest would deliver their homily or the pastor would deliver their sermon, the hourglass helped prevent anyone from becoming verbose.
Some people still use hourglasses for games and as egg timers in the kitchen. But the steampunk craze is bringing back the aesthetics of yore and hourglasses are experiencing an uptick of popularity within that subculture. They’re also often used symbolically in artwork and media presentations. The “wait” icon in some computer operating systems is a symbolic use of an hourglass
Cultural
Hourglass Motif : Because of its symmetry, graphic signs resembling an hourglass are seen in the art of cultures which never encountered such objects. Vertical pairs of triangles joined at the apex are common in Native American Art; both in North America. where it can represent, for example, the body of the Thunderbird or an enemy scalp, and South America, where it is believed to represent a Chuncho jungle dweller.
