Have a question for George? E-mail us.
Globe terms defined
Reference materials about globes
Who manufactured globes?
Labels pasted on globes
Mapping the Stars
Improving digital photos of maps
Restoring old planetaria
Condition of works on paper
How were 19th century lithographs made?
Q: Could you clear up a matter of the naming of these objects for me? You seem to make a distinction between armillary spheres, tellurians and orreries. I would be happy if you could tell me the difference amongst all of these. I had thought that tellurians were synonymous with planetaria and orreries. Is the main difference between celestial globes and orreries that orreries are mechanical? Thank you so much for helping a confused but dedicated amateur!
A: Planetaria (or planetary models) is a general term that includes armillary spheres, tellurians and orreries. To put it simply, armillaries are constructed from concentric rings, a tellurian is a mechanical device with a globe on the end of an arm, and orreries are mechanical devices with spheres on wire armatures. Our Glossary of Globe Terminology explains all these terms and more. By the way, occasionally you will also see combination armillary-orreries or tellurian-orreries.
I have recently started collecting world globes, and have had little luck
finding information on the net or in books about this interesting hobby.
Can you recommend any sites or publications I should consult?
Are there any e-mail discussion groups for globe collectors?
"Fledgling Globe Collector," New Zealand
A: We have added a list of recommended globe research and reference books to the web site that you may also order from ussee our globe books page. As for discussion groups, while we do not know of one specifically for globe collectors, there is one for the history of cartography called MapHist, which you can investigate further on the MapHist information page. The Oddens's Bookmarks site compiles web site references on the subject of cartography, with more than 17,000 listings last time we checked.
Q: Do you have more information about the people and companies that made the globes that you sell?
A: See our Guide to Globe Makers for biographies and histories of globe makers and manufacturers.
Q: What is that figure eight on maps and globes?
A: It's called an analemma, and it allows precise calculations of mean time (the time by which we set our clocks) by accounting for the tilt of the earth's axis. It also marks the solstices and equinoxes. Read all about it in the online Washington Post.
Q: How do you estimate the date of a globe?
A: Globes were frequently dated in the cartouche until about 1900. Thereafter, often they have no date, so you need to look at the geography.
Some geographical changes that can be used to date globes are:
For a comprehensive list of 20th century political changes helpful in dating globes, see the web site of globe manufacturer Replogle.
Q: Why do some globes have a label pasted over the original manufacturer's emblem?
A: British globe maker W. & A.K. Johnston had strategic business relationships with most of the major American Chicago globe makers, including A.H. Andrews, Rand McNally, Weber Costello, and A.J. Nystrom. These American globe makers and school supply houses often sold Johnston globes with an over-label pasted over the Johnston label. In that case, the royal coat of arms that surmounted the round cartouche often still showed. Read more about Johnston and the Chicago globe makers in our Guide to Globe Makers reference section.
Q: Where can I find more information about astronomical globes and maps - celestial globes, star maps, planispheres and so forth?
A: Learn more about different types of celestial globes and maps and find links to items in our site in our Collecting Celestial Globes section, which is based on an interview with George conducted by Martha Stewart on her TV show, Martha Stewart Living.
Q: I am trying to photograph my map collection, but as you can see from this image, my digital camera lens can't quite master a rectangle despite my hardest and most sincere efforts. The plate mark at the top slopes slightly downward from left to right and slopes towards the left as you move from the top right to the bottom right. I would like to crop the image to the plate mark and then "rebalance" the image so it is level and not tilted. I have Adobe PhotoShop LE 5.0 and Microsoft Photo Editor 3.0 on my computer. Does anyone know if my current editing software has this capability that I've not been able to uncover? I certainly don't want to spend big bucks on a full version photo editing program to provide this function if I don't have to.
A: Our webmaster has the answer to your question. She says your camera was not centered on the image, so the corners are not at right angles. This is called skewing. You can attack the problem two ways--by setting up your camera to minimize skewing or by correcting it in Photoshop. Read her step-by-step advice.
Q: I am missing the Sun on my Trippensee Planetarium and would like to know if you can sell me a replacement.
A: We do not sell spare parts, but Science First, which bought the Trippensee Planetarium Company does. Replacement parts are available for their current line as well as for older H and S models. For more information, contact them.
Q: My framed print looks like it is darkened, and has a waterstain in the bottom. Also there is a tear extending into the image. Does this hurt the value? Can a conservator repair the damage?
A: Condition is always a factor in value of a print. Often damages can be corrected to some extent by a professional paper conservator, but their work is expensive - generally at least $100 a print. So, if your print is not valuable, it probably does not pay to fix unless it has sentimental value or you just like it regardless of monetary market value. Here are some guidelines.
Framed Print: Carefully take print out of frame. Mats that are older than 20 years, corrugated cardboard, and wood backings are acidic and should be replaced. In reframing, ask your framer to frame to museum standard specifications with respect to backing materials, hinging, and UV plexiglass glazing.
Print Glued to Cardboard: This is not good for the print if the cardboard is acidic, because the acidic backing will cause the paper to turn brown over time. A paper conservator often can get the print off the backboard, generally by submerging it in water to dissolve the glue. This is a job for a conservator, because they must determine first if the process of removing the print from the backing will damage the print.
Dirty or Stained Print: Waterstains, dirt, spots, foxing. Foxing is comprised of small brown marks that seem to bloom on a print. Generally a dirty or stained print can be cleaned by a paper conservator. Sometimes it comes up completely clean. Sometimes some of the stains persist. If the print is colored, the print conservator might "lose" some of the color, so that has to be weighed in as a factor in deciding whether to restore.
Tears and Chips to Paper: A paper conservator can mend these or tip in missing pieces. Some tears become nearly invisible, some don't, but they cannot be eliminated.
Types of Paper: The type of paper used for the print is a factor in how well it will clean up with a restorer. For example, 18th Century laid paper made of cloth rags cleans very well. Some 19th century paper made of wood pulp will always be fragile and continue to disintegrate.
Q: How were 19th century lithographs made?
In the traditional lithographic process, a slab of limestone is ground to a smooth surface, on which the design is drawn in reverse with oil media such as a grease crayon. The non-printing parts of the design are sealed with a solution of gum arabic and acid, but the original drawing will receive ink when the plate is printed. Today, stones are still sometimes used for fine art printing, but most lithography is done on chemically-treated metal plates. Stones with original 19th century graphics, such as the one shown at left, are rare since the stones were often reused. (View a larger image.)