During the era of achromatic refractors in the 19th century, observatories were not as a rule located on rural, inaccessible mountaintops, but often were constructed on the campuses of metropolitan colleges. Some, like the Naval Observatory in Washington, were actually built in lowlands, with guaranteed bad 'seeing'! Pioneering studies of nebulae were accomplished in Great Britain, with a 60% frequency of cloud cover. Yet, thousands of celestial objects were scrutinzed by diligent, eagle-eyed searchers.

However, it is instructive to note that an item was missed, not discovered until the days of astrophotography: one of the most impressive and vast gas clouds in our galaxy, the "North American" Nebula. It is odd, considering that the object has the fortunate characteristic to be similar to a familiar earthly image, which of course was very well mapped by then, though satellite pictures would not come for many decades. The known concept of the commonplace map outline of the American continent aided the tendencies of the eye/brain to construct order when studying visual impressions.

If the viewer expects something to be present, as noted by Herschel, it may be seen with relative ease. Since no one had earlier seen the dusty cloud, the revelation of its faint outlines -- theoretically detectable in some of the short-focus comet hunting telescopes of the time -- had to wait for Dr. Max Wolf, a pioneering astrophotograper in Heidelberg, to perfect his techniques. His photograph, published in 1900 by the British magazine "Knowledge", seems as fine as a modern one. The German astronomer graced the nebula with its nickname, and the NGC, based largely on visual observations, described the object as "F, eeL" (faint, extremely large).

In "OBSERVING THE CONSTELLATIONS", John Sanford suggests:

"This is easier to photograph than to see well, but with large binoculars or a low-power rich-field telescope the 'continental' shape can be traced out reasonably well. 7 X 50 binoculars will show it on a really clear dark night, and the region definitely looks brighter than the surroundings with the well-adapted naked eye...(especially with a deep sky filter to remove auroral glow) the whole continent with the charming cluster NGC 6997 can be traced."

In 1995, author Waldee tested views near the light-polluted Santa Clara valley and in darker central California. A large Dob scope sweeps through the nebula, not able to provide low magnification, but with a 5.5" aperture f/3.6 instrument, the object is quite like our simulated images! It is pale, and just brighter than the background, but in a large field the outline of the "Gulf of Mexico" region is unmistakable, though nebulosity fades out in the 'higher latitudes'. Without a nebular filter (even in a very dark sky site) detection was difficult; with it the nebula was well-seen rising late one morning, over the heavily-populated Morgan Hill skyline.

Charles Chew enjoys photographing the Cygnus region around brilliant Deneb, and his color image was used for these simulations.

PICTURE NO. 1 (left): In a 5-6" richest-field scope, the star images will be sharper, but in a wide field ocular the region looks like this simulation, in an imperfectly-dark sky with some light pollution.

PICTURE NO. 2 (middle): By adding a narrowband general nebular-line filter, at a large exit pupil of 5 - 7 mm, the nebula is clearly detected as a pale gray mass, without the brilliant h-alpha red light of photographs.

PICTURE NO. 3 (right): The original 20 minute exposure. done by Charles Chew, with with a Nikon f/3.5 telephoto lens of 200-mm focal length. A broadband LPR filter improved contrast, and the film was Kodak Ektar 1000, hypered with forming gas. Sadly, the scanner we had in the early 1990s did not do full justice to his original picture, and we could only use 256-color depth for the "Eyepiece" program, whose color version is shown here.