While it’s uncertain who the inventor was, it is quite clear that spectacles quickly took hold into common use in that city, and use of them spread outward to the rest of the known world in just a few years. The Invention of Spectacles: The modern reinvention of spectacles occurred around 1280-1285 in Florence, Italy. Strangely, even though this must have worked quite well, and many people must have read this passage, there is no other evidence of spectacle use for over twelve centuries. The Emperor Nero used to watch in an Emerald the gladatorial combats.” This quote appears to be the first description of using a monacle for correcting short-sighted vision. Pliny the Elder wrote the following in 23-79 A.D.: “Emeralds are usually concave so that they may concentrate the visual rays. There is one very early description of an isolated use of spectacles. However, studies of early Chinese spectacles show that often the lenses were planar, without corrective abilities, and people may have actually used these colored glasses for cosmetic purposes rather than for astigmatism. Early Evidence of Spectacle Use: It has been said that spectacles were in use in China well before they were known in the West. It wasn’t until the invention of spectacles that optics came into common use. While the above exerpts give a glimpse at optical knowledge in the past, it’s important to realize that this knowledge was likely confined to the learned scientists and philosophers. If the letters of a book, or any minute object, be viewed through a lesser segment of a sphere of glass or crystal, whose plane is laid upon them, they will appear far better and larger. 1267 AD Bacon Wrote definite descriptions of simple magnification in his Perspectiva of 1267: “Great things can be performed by refracted vision. He wrote the following: “Letters, however small and indistinct, are seen enlarged and more clearly through a globe of glass filled with water.” 962-1038 AD: Arabian Scholar Alhazen: Wrote the first major optical work Opticae Thesaurus discussing not only optical principles, but described the anatomy of the eye, and how the lens of the eye focuses an image on the retina. 1st Century AD: Seneca: Described actual magnification by a globe of water. He then very accurately calculated the refraction constant of water. 2nd Century BC: Claudius Ptolemy:Described a stick appearing to bend in a pool of water, and accurately recorded the angles to within ½ degree for this relationship. Ancient Writings of Optics Several ancient manuscripts give us datable evidence of the state of refraction and optics throughout the ages. It’s now thought that lenses were not used nearly so long ago. It is now generally agreed that this stone was actually just an ornament which fell away from it’s mounting. Secondly, cloudy striae within the stone, which add an aesthetic quality, make it a poor magnifier. In the last century, however, studies of this object have shown that the curved surface is actually faceted, and not rounded, as one would have done to make a lens. This was long thought to be the first example of a plano-convex lens. The Lanyard Lens: The above is the famous “Lanyard Lens” discovered at Nimrod by Lanyard, and datable to 721-705 BC. This chapter should give some insighs on how optical theory developed making microscopy possible. Early History of the Lens: The first use of a lens is a bit of a mystery, but it’s now believed that use of lenses is more modern than previously thought. I great ly encourage anyone with corrections, disagreements, or suggestions to send me email About the Images in this Document: The images used in this document are derived from many sources, such as the original historic documents, the National Library of Medicine’s History of Medicine While I am working to replace copyrighted pictures, I urge anyone who wishes to use these images to research the copyright status before using them in non-private work. A number of good books exist on the topic, and several are listed under the Scientific Books section of the “Scientific and Medical Antique Collecting System” which I also encourage you to visit. I encourage you to visit this page as a complement covering some later developments. which covers more recent (20th century) improvements. Another “History of Microscopy” is maintained by Chris Jefferies in the U.K. This paper covers the early history of the microscope, starting with use of a simple lens in ancient times, to the first compound microscope circa 1590, up to the microscopes of the 19th century. Introduction: The microscope has become one of the most recognizable symbols of science. Ĭhapter 6: The Microscopes of the 19th Century Chapter 3: Microscopes of the 17th CenturyĬhapter 4: Mechanical Improvements of the 18th CenturyĬhapter 5: The Achromatic Lens Dispute.
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“ Parallel Migrations XXV,” Anne Dushanko-Dobek’s tribute to environmental justice and perseverance in the face of perilous journeys. Our #ThirdThursday Public Art Tours kick off with an Earth Day theme! Join us at Lake Lawson/Lake Smith Natural Area for a walk and discussion about Visit Virginia Beach Arts on Facebook for event details and updates. #MOCA MUSEUM VIRGINIA BEACH FREE#Our final sketch crawl before the unofficial end of Summer 2021 takes us back to the ViBe Creative District! New art is always popping up in the ViBe, so whether you joined the initial tour in April or are brand new, there will surely be something you haven’t seen! We’d dance with joy on the Maser Art stage if you join us!Įmail to RSVP and visit for more information.Ģ021 Spring/Summer #ThirdThursday Public Art Tour ScheduleĪll events are FREE and from 4pm-6pm. (4509 Commerce St., Virginia Beach, VA 23462) We’ll sketch them in this downtown tour! Tour begins outside of the Zeiders American Dream Theater. The Virginia Beach Town Center is a hub of arts and culture! When you’ve visited the area to watch a show at the Zeiders American Dream Theater or the Sandler Center for the Performing Arts, you may have noticed some public art easter eggs. During this crawl, you may even hear some tunes being played at the park gazebo! (524 Kempsville Rd., Virginia Beach, VA 23464) We’ll sprinkle in some history along with art for this crawl! Kempes Landing Park celebrates the historical Kempsville Area, and includes art pieces such as “ Good Game,” a tribute to the sportsmanship of local youth baseball. Saturday, J(EVENT WAS RAINED OUT RESCHEDULED TO JUNE 26, 2021) (104 Atlantic Ave., Virginia Beach, VA 23451) This crawl is in the heart of the Rudee Loop, which includes several murals, sculptures, vibrant placemaking features and is a stone’s throw from the Virginia Beach oceanfront! There are plenty of options to draw! (3663 Marlin Bay Dr., Virginia Beach, VA 23455) This bonus April tour will take you to the Pleasure House Point area of Virginia Beach, as we view and discuss the turtle-y awesome environmental art installation called “ Terrapin Basin.” The tour begins outside of the Brock Environmental Center. #MOCA MUSEUM VIRGINIA BEACH SERIES#We’ll kick off our 2021 #SecondSaturday Sketch Crawl Series in the ViBe Creative District! We’ll gather at the Virginia Museum of Contemporary Art (MOCA), then chart a course through the murals of the ViBe, ending at the City of Virginia Beach’s latest public art installation, “ Barreled!” Visit and Virginia Beach Arts on Facebook for event updates.įREE sketching supplies are limited, so arrive early! 2021 Spring/Summer #SecondSaturday Sketch Crawl ScheduleĪll events are from 1pm-3pm. □ Is the mountain feist dog an official breed?Ī Most Unique “Breed” On paper, the Mountain Feist is an unusual dog. Mountain feist lifespan | how long can a mountain feist live?.□ What is a mountain feist breed of dog? The Mountain Feist is a dog breed, very similar to Jack Russell Terrier originating from the southern portion of North America. The color their coat comes in a large variety and include red and white, blue and white, black and tan, red brindle, red, black, and spotted tricolors. They have a height range of 12-17 inches at the withers, with a short, dense and smooth coat. Most of their ancestory can be traced to terrier breeds but it is thought that they may also. Is the mountain feist a good breed of dog? Physically, feists are small- to medium-sized dogs, ranging in weight from 10-30 lbs. They are not recognized as a breed by the American Kennel Club.
While you may spend a lot of time doing this in German class with your teacher, this is a constructed environment. Learning German at a higher level means formulating your sentences and speaking like German native speakers. Listen to and watch German media to hear native speakers If you’re learning German to study Engineering, it might not make so much sense to learn tons of food-related vocabulary.Īsk yourself: what is my purpose for learning German and what related vocabulary and phrases do I need to know to feel comfortable speaking in German efficiently and effectively? Once you have this answer, this is what you should focus your practice on. For example, if you’re learning German to work in business, it probably doesn’t make sense to learn German philosophy vocabulary. Keep your practice relevant for youīecoming fluent in German doesn’t mean learning every vocabulary word there is to know (this is actually impossible anyway due to composite words). It’s this point that propels you forward in becoming fluent, because when you learn to format sentences in a German way, you also begin to think “like a native German”. When you know how basic grammar works, you can combine vocabulary and grammar to create your own sentences. Learn basic german grammar how to#While many popular language apps give great vocabulary, they often don’t teach you how to use this vocabulary in different contexts and how the grammar is formulated. I would personally stress this third point: learn to form your own sentences. If you’re looking to be fluent in German in 3 months, you’ll want to give the Lingoda Sprint a go, because you learn the ins and outs of German grammar, get to practice speaking with native speakers, and also learn to form your own sentences. How long does it take to be fluent in German? Well, in order to get to “fluency”, you need to spend a lot of time practicing, but this can be done in a short period of time if you’re dedicated enough. In my opinion, this “fluid conversation” is what makes a person “fluent”, so I’ve compiled a few helpful tips to get you there. The most important is that people can understand you, and that you can understand others well enough to have a fluid conversation. What I can also say is that grammar isn’t as important as you might think. And while it is definitely complex, there is a lot of fun to it, too (I particularly love making up composite words). During my time at German language school, we spent a lot of time going over German grammar. The tricky part for most, however, is German grammar. But the good news is that if you’re familiar with English (or are a native English speaker like me), there are a lot of English words and phrases that are the same in both languages, such as “information”, “finger” and “minute”. As someone who has learned German as an adult, I won’t lie to you and say that German is easy to learn without practice. |
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