Roy Chapman 

 Andrews would 

 be proud of our 

 new Museum 

 Expedition Hat" 



For 125 years, scientists 

 from the American Museum 

 of Natural History have 

 braved harsh elements, 

 rugged terrain, and the blaz- 

 ing sun in their quest to 

 unlock the earth's mysteries. 

 In their explorations around 

 the globe, they would don 

 this distinctive, wide- 

 brimmed canvas hat for pro- 

 tection and comfort. Now, 

 for the explorer in all of us, 

 this classic Museum head- 

 gear can be yours. 



Worn by such 

 legendary Museum 

 explorers as Roy 

 Chapman Andrews 

 — said to be the 

 inspiration for 

 Hollywood's 

 "Indiana Jones"— 

 on his expeditions 

 to China and 

 Mongolia in the 

 1920s, the rugged 

 American Museum of Natural 

 History Expedition Hat goes 

 anywhere. It's made of 100% 

 natural, double-thick, pre- 

 shrunk cotton canvas, 

 and features a 

 3-1/2" brim, 

 brass grom- 

 mets, and 



a chin strap with adjustable 

 Nexus cordlock. It crushes 

 for easy travel. Best of all, 

 each purchase benefits the 

 Museum and the new expe- 

 ditions launched each year. 



The American Museum 

 of Natural History 

 Expedition Hat, $29. 

 Add a bandanna or leather 

 hatband for $4 each. 

 To order, call toll-free: 

 1-800-852-0925. Major 

 credit cards accepted. 

 Sizes S - XXL available. 

 Satisfaction guaranteed or 

 return within 30 

 days for full 

 refund. 



American Museum of Nsjtural History 



Central Park West at 79th Street, NY, NY, Mli 1-800-852-0925 



dence, the sun is 400 times farther away 

 from us than the moon, but it is also 400 

 times larger than the moon, so that in the 

 sky the two appear to have roughly the 

 same diameter This is what makes solar 

 eclipses so spectacular.) During apogee, 

 however, when the moon is farthest from 

 us, its disk is not large enough to cover the 

 sun completely, so a ring, or annulus, of 

 sunlight escapes around the edges. Along 

 one side, the ring is often broken up into 

 bright points of light by mountains on the 

 moon's surface. 



During May's annular eclipse, the 

 moon's disk will cover 88 percent of the 

 sun. Even 12 percent of sunshine in the 

 ring of annularity is still a lot of hght, how- 

 ever, and although the sky will become 

 darker, it won't be spectacularly so. At the 

 height of the eclipse, the lighting will be 

 equivalent to that of a heavily overcast 

 day. What will be striking is that the edges 

 of shadows will get sharper (because Ught 

 is coming from a smaller source), and 

 hundreds of pinhole images of the sun will 

 be seen under trees as the image of the sun 

 is filtered through the leaves. 



This effect can be simulated by making 

 a pinhole in a card and projecting the 

 image of the sun through it onto a sheet of 

 paper This method is one way of viewing 

 eclipses safely. To look at the sun during 

 eclipses, you need special filters to protect 

 your eyes from its direct rays, which can 

 quickly cause permanent damage. Be- 

 cause all the bright photosphere of the sun 

 is hidden by the moon in a total solar 

 eclipse, during totality, observers can 

 safely look directly at the eclipse with the 

 naked eye. Annular and partial ecUpses, 

 however, can never be viewed safely be- 

 cause some of the solar surface remains 

 exposed. If you must look directly at the 

 sun, use a rectangular welder's glass of 

 shade number 14, which can be purchased 

 at hardware stores and welding supply 

 firms. Welder's glass of lower shade num- 

 bers are not safe for solar viewing. Nor do 

 gelatin filters, color film, photographic fil- 

 ters, smoked glass, or sunglasses offer any 

 protection. 



Viewers near the center of the eclipse 

 path will see a symmetrical ring of sun- 

 light around the moon, while those near 

 the edges of the track will see the moon off 

 center in the solar disk. At its best near 

 Toledo, Ohio, the annular phase of the 

 echpse will last six minutes and thirteen 

 seconds. The rest of the United States, as 

 well as Canada, Mexico, Central America, 

 Greenland, Iceland, the Arctic, and por- 

 tions of Europe and Africa, will witness a 



74 Natural History 5/94 



