My Telescope

The refracting telescope undoubted is considered as one of the most important discoveries in astronomy. Planets, features of the Moon, other planets’ moons and other heavenly objects within the solar system and beyond – these are the many significant finds of the refractor as a major type of astronomical telescope.

Galileo Telescope, one of the earliest refractor, was considered the first astronomical telescope to be used seriously and professionally in the study of the heavens. It paved the way for the development of astronomy as a major science.

Famous Refracting Telescope / Lenses Manufacturers of the Early Times

Alvan Clark, astronomer and lens maker created Alvan Clark and Sons in 1846, the company that manufactured the best scope lenses.

Alvan Graham Clark created the 26 inches lens of the United States Naval Observatory, as well as the lenses in Yerkes Observatory and Lick Observatory.

The Carl Zeiss Company was also a major Zeiss refractor manufacturer in the first half of the 1900’s. The company installed at the Griffith observatory the 12 inch (1 foot) Zeiss scope in 1935.

Zeiss also manufactured the refractor for the Gifford Observatory found in Wellington, New Zealand at Mount Victoria. The 130 mm Zeiss scope underwent major restoration and is presently in the observatory for astronomical use.

Although today the refracting telescope is not being manufactured to be used professionally – it has firmly earned its place in the history of astronomy as one of the most useful and prolific astronomical instruments of all times.

Located in the northern side of Pittsburgh, the Buhl Planetarium or Buhl Science Center opened in 1939 and became a major planetarium and astronomy center in the United States.

Two years later its refracting telescope observatory became operational, and become known as the People’s Observatory, aptly named as it was dedicated to the public. Very much involved with the founding of the People’s Observatory was Harlow Shapley, a well known American scientist and astronomer of Harvard College Observatory, who dedicated it to the public in 1941. (The moon’s Shapley crater was named after him.)

The People’s Observatory featured its major refracting telescope instrument – the 25.4 centimeter (10 inch) Siderostate refractor telescope.

Actually before the 10 inch refracting telescope came to be used by the astronomical observatory, a 10.16 centimeter (4 inch) Zeiss scope was bought by Buhl. But it was apparent upon its use and checking of its specifications and astronomical and optical functions that they made the mistake of purchasing the Zeiss scope.

So the 25.4 centimeter refracting telescope immediately took over upon its acquisition albeit the Zeiss refractor is still being used at the Henry Buhl, Jr. Planetarium.

The planetarium also has an observatory dome where astronomical enthusiasts and find and use a Mead reflecting telescope.

The Vatican observatory is said to be one of the oldest astronomical telescope observatories in the world.

Before the Vatican observatory, the Papacy built three previous observatories, the Roman College Observatory, the Specula Vaticana, and Observatory of the Capital.

In 1891, this refracting telescope observatory was rebuilt – this time it was constructed on a hill near the St. Peter’s Basilica.

But because of the development and growing population of the City of Rome, its skies became too bright for astronomical studies making it less than ideal for the Vatican Observatory to stay there.

So the Vatican Observatory transferred at the Summer Residence of the Pope located in Castel Gandolfo which is southeast of Rome.

Still the continuing increase brightness of the Roman skies slowly but steadily affected the scientific and astronomical research of the observatory.

Because of this, the Observatory in 1981 built a second an astronomical research group, known as the Vatican Observatory Research Group (VORG), in Arizona, US. The research group is considered one of the best and modern in the world.

The Vatican refracting telescope observatory has one of its major refractor and astronomical telescopes the Zeiss refracting telescope. The Zeiss scope was mounted and made available on the 29th of September 1935.

The aperture of the Zeiss scope is 40 centimeters.

Other important specifications of the Zeiss refracting telescope is the Focal Length which as 600 centimeter and the Image scale which is 34 inches / mm.

Aside from the Zeiss scope, other astronomical telescopes and instruments at the observatory are the Double Astrograph, Schmidt and Lennon Telescopes.

The basic design, the function of the eyepiece and lens, and optical mechanics of a refracting telescope is so simple that even a middle school student would be able to enumerate its parts, lens and eyepiece – few as they are.

While it is a fact the refracting telescope is one of the simplest types of astronomical telescope – it contributes greatly in the science of astronomy being one of the more important and major instrument utilized in many innumerable astronomical discoveries.

It is unfortunate that the refractor is an imperfect instrument as it possesses a major technical flaw which is known as the chromatic aberration. Chromatic aberration is a defect in which all the lights that pass through the lens do not meet on one point of focus. This in turn renders the vividness and clarity of the images to become inferior.

Because of such defective feature of the refracting telescope, this astronomical telescope gradually became known as an ineffective type of telescope. The refractor acquired the image of being not very reliable for astronomical gazing, study and research.

The popularity of the refractor as a dependable astronomical and stargazing instrument continued to dwindle all the more especially with the invention of a more improved version of the reflecting telescope. Eventually, the reflecting telescope took over the refracting telescope as the important astronomical telescope of modern times.

The fact is, there is not a major refractor built and constructed in recent times.

But the honor can not be denied – the discovery of this astronomical telescope is indeed one of the most important events that helped greatly in the advancement of the science of astronomy.

One of the smaller, more “personal” but popular like the world’s major refracting telescope observatories, the Crosby Ramsey Memorial telescope observatory can be found at the Maryland Science Center, right at its rooftop. Aside from the Observatory, the science center, located at the Inner Harbor, Maryland has exhibits including dinosaur displays which are open to the public. The Maryland Science Center continues to improve and grow and the latest addition to its modern facilities is a state of the art theater

The memorial observatory has as its scope centerpiece the computerized and improved 8 inch refracting telescope. The observatory bought this refractor from the famous optical lens manufacturing company Alvan Clark and Sons way back in 1927.

And because improvements are done on the Crosby Ramsey’s Alvan Clark refracting telescope – it now boasts of being able to provide and capture astronomical images aside from the usual near earth objects like the moon.

Computerization likewise makes stargazing a lot easier – the refracting telescope trains itself to whatever sky object an observer desires to view by the simple use of commands.

The Crosby Ramsey telescope observatory continues to improve and grow and the latest addition to its modern facilities is a state of the art theater.

The telescope observatory is committed in providing its services to the public, and is open to everyone on Thursdays and Sundays for its sun and star gazing activities.

In New Zealand is a popular refracting telescope observatory named the Gifford Observatory. The Gifford observatory can be specifically found on Mount Victoria, in Wellington.

The refracting telescope observatory, which has become one of Wellington’s great pride when it comes to great contributions to the advancement and promotion of the science of astronomy and stargazing, was founded in 1912 by Charles Gifford who is a scientist, astronomer and college mathematics professor.

The astronomical telescope centerpiece of the observatory is the 130 mm Zeiss refracting telescope. Together with the scope were excellent astronomical instruments such as a photograph developing instrument, a spectroscope, and an astronomical camera or an astrograph.

The refractor is as popular as the Gifford observatory’s founder as both pictures of the Charles Gifford and the refractor are hanging on the observatory building’s wall.

Unfortunately, during the 1970’s the Gifford astronomical facility lost its former excellent condition and begun to deteriorate until it became not fit to operate.

In recent years however, after some time of undergoing renovation and restoration, the Gifford refracting telescope observatory finally becomes fully operational today and are being used mostly for the students of Wellington for group study sessions, as well as the local astronomical societies.

The Griffith refracting telescope observatory was founded by Griffith J. Griffith, a millionaire from Los Angeles, California. The popular observatory can be found in the City of Los Angeles, on Griffith Park, Mount Hollywood. The location affords visitors magnificent sights of many places in California such as Los Angeles itself.

Griffith was inspired to built the observatory after he visited the Mount Wilson Observatory.

With construction money of 100,000 dollars from Griffith, he instructed the building of the observatory on Mount Hollywood. The mountain top observatory was finally open on 1935 with its facilities available to the public.

Later after his death, ownership and operation of the Griffith Observatory was turned over to the city of Los Angeles.

One of the more popular astronomical telescope at the Griffith Observatory was the 12 inch (1 foot) Zeiss refracting telescope.

Ever since the opening of the observatory, this refracting telescope became available to the public, mostly people of Los Angeles and California. It became the stargazing refractor for the general public.

It is even said that many celestrial and astronomical objects such as comets and asteroids were viewed through the Zeiss refractor than any other refracting telescope in the United States.

Another astronomical telescope worth mentioning is the Dollond refracting telescope.

This refractor with glass and brass as the main materials was assembled and built by London optical instrument maker George Dollond in the year 1836 in England.

Some of the important optical specifications and qualities of the Dollond refracting telescope are:

This refractor’s focal length is 0.3 meters or 300 centimeters. Focal length is the length of the path from the lens to the eyepiece through which light passes.

Length and height are both measured at 18 centimeters.

The refractor’s aperture is measured at approximately 18 centimeters. The aperture is defined as the diameter of the primary mirror or lens of the telescope. The higher the value of the diameter of the mirror or lens, the more vivid and detailed with be the image.

The Dollonds – famous astronomical and refracting telescope builders

George Dollond was a famous European inventor, optician and eyepiece maker. His scientific inventions were important gadgets utilized not only in the field of astronomy, but also in navigation.

George Dollond, together with father John and uncle Peter, became very famous all over Europe as being great builders and inventors of astronomical telescope equipments, as well as reliable navigation gadgets, equipments and instruments.

The mechanics of a refracting telescope is easy enough to be understood even by non-enthusiasts.

Anyone with little skill can even build a simple refracting telescope. But of course, the most important parts of this astronomical telescope are its lenses.

As we already learned from my earlier post on this type of telescope, its two lenses are the objective lens and the eyepiece lens.

Once you have these two lenses, you are on your way to building your first astronomical telescope for your stargazing endeavors.

The objective lens is convex lens – the light gathering lens, and the larger of the two. This lens is found at the front end of the telescope tube.

The eyepiece lens, on the other hand, is on the opposite end of the tube and the one that magnifies the picture or image of the object.

Should anyone decide to assemble a refractor, it is best to go to a recognized scope dealer and manufacturer in your area for the best lenses.

A refracting telescope has been eclipsed by more modern astronomical telescope – this is due to the fact that this telescope delivers less than perfect images for astronomical enthusiasts to enjoy.

Nonetheless, many telescope novices choose the refractor when building their own scope. This is because of the fact that parts of the refracting telescope are few, simple and readily available.

Related Posts:
Refracting Telescope: Today's Modern Galileo Telescope
Refracting Telescope: On Brightness and Magnification

The history and invention of the refracting telescope would not be complete without mentioning Hans Lippershey.

Lippershey is not only credited with the invention and construction of the first refracting telescope, but also of the world’s very first practical telescope.

In fact the Lippershey refractor was the sole model of the Galileo telescope – the first real astronomical telescope and a much more improved version of refracting telescope, in terms of mechanics and astronomical stargazing.

A Dutch optician and lens maker, Hans Lippershey was born in Germany but spent his life in Middelburg, Netherlands. Lippershey was experiencing success as a maker of spectacles, since he belong to a flourishing trade at that time.

Lens making became more established and exciting when new techniques on glass making were brought it from Italy.

There were contentions that the refracting telescope was not an idea original to Hans Lippershey but actually to his children, whom he observed one time playing and tinkering around with some lenses.

Still it is needless to say that Hans Lippershey should be given the same importance and credit many accord to Galileo Galilei when it comes to the invention and evolution of the refracting telescope.

Similar post: Refracting Telescope: Lippershey’s Invention

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With the lens built by the German telescope building company Merz and Mahler, this 15 inch (or 1.25 feet) refracting telescope was constructed in the Harvard compound, in Cambridge, Massachusetts in 1847.

For two decades, the Merz and Mahler Refracting Telescope, which is more popularly known as the Great Refractor, was the largest astronomical telescope in the United States.

The Great Refractor was housed by the Harvard College Observatory, Harvard University’s center of research on astronomy.

During its time, the Harvard’s refracting telescope was popular for being instrumental in capturing and producing very vivid and detailed images of the moon. In fact, some of these images won recognition in the international photography exhibition at the London Crystal Palace.

Another important achievement was the eighth satellite and inner ring of Saturn, which was a feat of father and son W. Bond and George Bond.

Still another achievement was the daguerreotype of the star Vega.

Other important astronomical finds done with the 15 inch refracting telescope was the discovery of asteroids and other near earth objects.

Today, the Great Refractor is used mainly for observation purposes and students’ astronomical researches.

In Shreveport, State of Louisiana is where you can find the Ralph A. Worley astronomical telescope Observatory. The reflecting telescope and refracting telescope observatory was constructed in 1964 by a group of astronomy enthusiasts called the Shreveport-Bossier Astronomical Society, to be later donated for use by the Caddo School System.

Presently the reflecting telescope / refracting telescope observatory is used by the Louisiana State University at Shreveport (LSU-Shreveport) for their scientific and astronomy classes.

Likewise, astronomical groups and associations take advantage of this observatory in Shreveport – and many stargazing sessions, astronomical classes, meetings and programs, as well as astronomical lectures are being held at this Shreveport observatory.

The Ralph A. Worley Observatory is home to a Newtonian reflecting telescope (16 inches) and a 6 inches refracting telescope. The Worley Observatory has actually two telescope buildings – The dome type building houses the Newtonian reflecting telescope, while another building (this one has a leveled roofing) beside it contains the 6 inch refracting telescope.

The Ralph A. Worley is still available for various astronomical researches and stargazing, albeit currently it is in a stage of major upgrading and maintenance.