what does 18th century A.D. mean?
607303
yup.\n18 century is 1700's\n\nbtw it was found by the chinese earlier than that\n\nGunpowder is considered one of the Four Great Inventions of the Chinese, though in fact it is not known whether it was first invented in China.\n\nThe first type of gunpowder was black powder. Neither its inventors nor exact date of creation is known. Historians of various cultures have postulated that it was invented between the seventh or ninth centuries by either the Chinese or the Arabs. In the West, Roger Bacon was the first to describe the formula for gunpowder on the ground of a passage in his On Marvelous Power of Art and Nature in 1242, leading many in the ensuing centuries to the mistaken belief that Bacon invented gunpowder -- even though Bacon himself mentioned that gunpowder was known in diverse places (see Opus tertium, by order of Pope Clement IV in 1266). It is also possible that black powder was invented independently by more than one culture at around the same time. As James Partington states in A History of Greek Fire and Gunpowder:\n\n    "Gunpowder is not, of course, an 'invention' in the modern sense, the product of a single time and place; no individual's name can be attached to it, nor can that of any single nation or region. Fire is one of the primordial forces of nature, and incendiary weapons have had a place in armies' toolkits for almost as long as civilized states have made war."\n\nRegardless of origin, gunpowder was the first chemical propellant and the first explosive recorded in history.\n\nThe Arabs are generally credited with being the first to purify gunpowder to contain almost no sodium nitrate (only potassium nitrate) and to have a high enough quality to use effectively as a combat explosive. By the 15th century they had invented both a rocket and torpedo, both spear-tipped. The spear would lodge into a boat or other large surface and then the explosives would detonate as the propellant burned out.\n\nOne of the flaws of black powder in its original form was its tendency to "demix" under the effects of vibration, e.g. in the knapsack of a marching soldier. The component ingredients would separate, and the powder sample poured into a gun would not have the correct proportions. The same volume of powder, depending on its vibration history and whether it was sampled from the top or bottom of the powder container, could either fizzle or burst the gun barrel. "Corning" is the process that prevented demixing and made black powder far more reliable. It was invented in Europe around the fifteenth century, and involves forcing damp powder through a sieve to form it into granules. Each granule contains a mixture of the three ingredients with nearly optimum proportions.
232744
Maybe like 200,000a year.
1143655
It could be that they are giving a number to mean a long amount of time. It could be that a year was measured differently in his time. It could be a translation issue. Maybe the world they are translating is supposed to be month and not year. If so, if he lived 950 years, it would actually be just over 79 years.
784578
1789 - 1776=13\n\n;-D All hail the chief!
95030
findout_22 - 1974? What kind of answer is that? \n\nI suspect it is sometime in the ealr 1900s...probably 1912.
780333
Epistolary Novels (made of correspondace) were extremely popular in the 18th century
88230
yup, AD usually stands for anno domini.  however, to help children understand it better, sometimes they refer to AD as after death (of christ) and BC as before christ.  however, this is very hypothetical since christ died during 33 AD leaving us to wonder how we will address 0-32.  limbo years?
291816
AD: Anno Domine in the Christian era; used before dates after the supposed year Christ was born; "in AD 200" \nwordnet.princeton.edu/perl/webwn\n\nBC: Abbreviation for the term Before Christ. Years are counted back from the traditionally recognized year of Christ's birth. In academic, historical, and archaeological circles, this term is now generally replaced by Before Common Era (BCE).\nwww.archaeological.org/webinfo.php
333562
Usually it refers to people who lived before the sack of Rome in the early 5th century AD. It's very non-specific, though, and the precise meaning depends upon the context.
639340
I am sure that is what Britain said back in the 1770's and 1780's about the US.
701366
i'd love to live in the late 1800's ... some modern some rustic and the beautiful dresses and the furniture!  thanks for asking this question!  = )
42245
Definitions of a.d on the Web:\n\nAD: in the Christian era; used before dates after the supposed year Christ was born; "in AD 200" \nwordnet.princeton.edu/perl/webwn\n\n\nThe system of numbering years A.D. (for "Anno Domini") was instituted in about the year 527 A.D. by the Roman abbot Dionysius Exiguus, who reckoned that the Incarnation had occurred on March 25 in the year 754 a.u.c., with the birth of Jesus occurring nine months later. Thus the year 754 a.u.c. was designated by him as the year 1 A.D. It is generally thought that his estimate of the time of this event was off by a few years (and there is even uncertainty as to whether he identified 1 A.D. with 754 a.u.c. or 753 a.u.c.).
660821
Well, obviously it is not from 1789. In Denver? At that time, the US Constitution had only been signed for about a year, the Department of the Treasury was formed by Act of Congress that year. So you have a coin that commemerates the founding of the Treasury and shows the Treasury Dept bldg in Washington DC. There should be a date showing the striking date and a valuation somewhere on the coin. Good luck in finding out more about it. I would suggest looking at some numismatistic sites on google.
659478
I think he meant to ask why a day is divided into 24 and not 36 or 48. The actual time would be the same but there would be short intervals. A half hour would end up being an hour. Why divide a circle into 360 or an hour into 60. \n\nHour :- "a traditional unit of time, equal to 60 minutes, or 3600 seconds, or 1/24 day. The custom of dividing the daylight into 12 hours goes back at least as far as the Babylonians, who liked to divide units by 12 because groups of 12 are easily divided into halves, thirds, or fourths. Originally an hour was 1/12 of the time between sunrise and sunset, so summer hours were longer than winter hours. Later, when people wanted to express times at night, it was natural to divide the night into 12 hours as well, making 24 hours in the day. Only after the invention of mechanical clocks, around 1300, did hours became equal intervals marked by clocks. The word comes from an ancient Greek word hora which originally meant a season, especially a religious season, and hence a "defined" period of time. In the Christian church hora came to mean one of the services held at seven specific times during the day, thus establishing the word as marking subdivisions of the day."
786254
Federalists, if you mean in 1700's.
87755
The U.S.A. has  been a country for 229 years. Declared independence in 1776
416427
The 22nd century starts in the year 2100\n\nSome would argue that as there was no Year 0 the first century started in 1 AD and was only 99 years long instead of 100 years long. And therefore all subsequent centuries should start in 101, 201 ... 2001, 2101.\n\nI don't agree with that point of view but it exists.