A para-focal lens set is a set of lenses that when interchanged one for another will not require refocusing, the image of the specimen will remain in focus.
Short answer: Zacharias Jansen Long answer: Your question is not valid for 2 reasons: 1. You cannot "discover" something if it does not exist. You should be asking who invented it, not who found it laying around somewhere. 2. A "simple microscope" is not common terminology. Simple compared to an electron microscope? or simple compared to a compound microscope? What is typically referred to as just "microscope" is technically a compound microscope. A set of multiple lenses mounted in a desktop style that allows the compounding of magnification. A compound microscope is the standard microscope in any basic lab setting. Anything more "simple" than a compound microscope would not even really be a microscope, it would either be a telescope, or simpler than that is a magnifying glass (with a single lens) The inventor of the magnifying glass was: Roger Bacon The next step up is the telescope invented by: Zacharias Jansen The next step up is the "compound microscope" which was also invented by: Zacharias Jansen (this is the simplest form of what would be recognized as or named "microscope") If you wanted to go even "simpler" and define microscope as anything that magnifies, there were reading glasses around for thousands of years prior, and even "reading stones" which were lumps of polished glass used to magnify parchment in Egypt as far back as 7000 B.C. (inventor unknown). So it really depends on how you wish to refine your meaning of simple. The magnification of anything? There is no known inventor for reading stones, his name is lost to time. Or if you mean the first invented microscope that could examine things too small for a human eye to detect, that's a compound microscope. Thus if I am guessing your meaning correctly, you meant to ask this question: Question: Who invented the compound microscope? Answer: Zacharias Jansen
The first record of the use of lenses to manipulate images was in Greek and Roman writings of around 1000 A.D. As for the origins of someone using lenses to magnify a minute object, it is unclear. Most scientific instruments have a clear place in the historical records when they were formed and who created them, not the microscope though. The definition of the microscope makes it difficult to determine when it was first created. Since there were lenses dating back to ancient societies, how do we say when those lenses were used to look at minute objects? It is practically impossible to say when a single lens was used in that fashion. Credit for the first compound microscope (multiple lenses) is generally given to Zacharias Jansen and John Lippershey of the Netherlands, in 1590. It is likely that the microscope was a result of work made on the telescope. The telescope had much more practical uses in that time, because it could be used for maritime navigation.This idea is supported by the account of one of the first compound microscopes, which was six feet long and had a one inch barrel with a lens at either end. After the compound microscope the next major development was in lenses. Half a century after the compound microscope, both Anthony van Leeuwenhoek and Robert Hooke realized that lenses with very short focal lengths was the key to more magnification. This meant the use of extremely double convex or spherical lenses. They also used lenses made of pure quartz, creating a more pure glass instead of the poor quality, greenish glass of the day. The problem of making lenses in this fashion was that it created chromatic aberration. This aberration is because different wavelengths of light are refracted different amounts, resulting in a smeared image instead of a clear one. In 1758 John Dollard patented an achromatic lens. Even with this new lens, it was not until 1930 when Lister was able to use it to alleviate the problem of chromatic aberration. Much of the interim time was spent on telescope technology. Another form of the microscope, first proposed by Isaac Newton in 1692, is the reflecting microscope. In this case the light would not pass through a lens, but would reflect off of a concave mirror. Since all light is reflected the same, there would be no problem with chromatic aberration. The first reflecting microscope was made by Barker in 1736. This model was developed directly from reflecting telescope designs. Reflecting microscopes are used today, but the transmission type are much more prevalent.
The first record of the use of lenses to manipulate images was in Greek and Roman writings of around 1000 A.D. As for the origins of someone using lenses to magnify a minute object, it is unclear. Most scientific instruments have a clear place in the historical records when they were formed and who created them, not the microscope though. The definition of the microscope makes it difficult to determine when it was first created. Since there were lenses dating back to ancient societies, how do we say when those lenses were used to look at minute objects? It is practically impossible to say when a single lens was used in that fashion. Credit for the first compound microscope (multiple lenses) is generally given to Zacharias Jansen and John Lippershey of the Netherlands, in 1590. It is likely that the microscope was a result of work made on the telescope. The telescope had much more practical uses in that time, because it could be used for maritime navigation.This idea is supported by the account of one of the first compound microscopes, which was six feet long and had a one inch barrel with a lens at either end. After the compound microscope the next major development was in lenses. Half a century after the compound microscope, both Anthony van Leeuwenhoek and Robert Hooke realized that lenses with very short focal lengths was the key to more magnification. This meant the use of extremely double convex or spherical lenses. They also used lenses made of pure quartz, creating a more pure glass instead of the poor quality, greenish glass of the day. The problem of making lenses in this fashion was that it created chromatic aberration. This aberration is because different wavelengths of light are refracted different amounts, resulting in a smeared image instead of a clear one. In 1758 John Dollard patented an achromatic lens. Even with this new lens, it was not until 1930 when Lister was able to use it to alleviate the problem of chromatic aberration. Much of the interim time was spent on telescope technology. Another form of the microscope, first proposed by Isaac newton in 1692, is the reflecting microscope. In this case the light would not pass through a lens, but would reflect off of a concave mirror. Since all light is reflected the same, there would be no problem with chromatic aberration. The first reflecting microscope was made by Barker in 1736. This model was developed directly from reflecting telescope designs. Reflecting microscopes are used today, but the transmission type are much more prevalent.
by suckin it baby
If you meant "compound" the answer is "H2O" or "water." If you meant "element" the answer is "hydrogen."
If you meant carbon disulfide, it is a compound, CS2
The smallest unit of a compound.
It is a compound that has a non superimposable mirror image, and an asymmetric center.
If you meant scissors, the the answer is yes.
The ability of a microscope to measure by separation images that would be difficult to see with the naked eye. This separation is called angular separation.
Assuming you meant Aluminium - no - it's an element.
Yes, Carbon Dioxide is a Compound its symbol is CO2 (Note Number is meant to be small)