The first unmanned hot-air balloons are attributed to Zhu Geliang, a military strategist in post-Han China (181–234 ce).1 A household name in China, Zhu Geliang is remembered for his deep wisdom and dedication to duty as well as his resourcefulness as an inventor. Adapting paper lanterns to create the first lighter-than-air craft, he mounted across the neck at the base of the lantern a small cloth wick, soaked in a flammable liquid. When lit, the flame both illuminated the "lantern" and provided the heat necessary to create the buoyancy for the balloon to lift off. Clearly visible in the night sky they were an effective means of signalling his troops. Zhu Geliang also went by the name Kong Ming. Today, these lanterns, known as Kong Ming lanterns, are released throughout Southeast Asia at festivals to symbolize hope and a bright future. In November of 2004, a Guinness World Record was set when 1,888 Kong Ming lanterns were released into the night skies over the city of Wanning in Hainan, China.2 While the launching of Kong Ming lanterns into the night sky can be breathtaking and is fast becoming a tourist attraction, many jurisdictions are banning them due to the risk of fire and disruption to air traffic. More than fifteen centuries after Zhu Geliang's lanterns, two French brothers took the development of lighter-than-air craft to the next level—manned flight. Once again paper played a major role. On June 4, 1783, brothers Joseph and Etienne Montgolfier, members of an established papermaking family in Annonay, France, inflated a paper and linen envelope with hot air. The brothers' first unmanned public flight lasted less than ten minutes with the balloon traveling more than a mile before landing. \[See Reynaud's article in this issue. Ed.\] A tradition of building and flying unmanned paper hot-air balloons continues to this day in several parts of the world. Small towns and villages in Italy fly paper hot-air balloons during feasts of patron saints. In 1994 the Association of Italian Hot-Air Balloon Makers (A.R.I.A.) was founded with the aim to promote and develop balloon culture and increase the number of knowledgeable, paper hot-air balloon makers. Each year artists and balloon enthusiasts participate Building and Flying Paper Hot-Air Balloons brian queen ___________ notes 1. "Hot Air Balloon" from the Wikipedia website. Retrieved December 27, 2005 from http://en.wikipedia.org/ wiki/Hot_air_balloon. 2. "Flying lanterns light up skies, make record books" from the China Daily website. Retrieved January 5, 2006 from http://www.chinadaily.com.cn/english/doc/2004-11/25/ content_394700.htm. 3. For more information about A.R.I.A., go to the association's website: http://www.ariaonline.it/ (retrieved on December 17, 2005). 4. For more information about Brazilian balloons, go to Edilson Lima Rigapov's website: http://www.balloons.tk/ (retrieved on December 17, 2005). 5. For more information about Argentinean balloons, go to the Turma del Plata website: http://www.tdplata .com/ (retrieved on December 26, 2005). Floating paper lanterns fill the sky over the Andaman Sea in a one-year anniversary remembrance of tsunami victims in Khao Lak, Thailand, on December 26, 2005. Photo: Adrees Latif, Reuters.   in the "Flying Frescos" competition for cash prizes. The A.R.I.A. also collaborates with schools where the construction and flight of hot-air balloons aid in the teaching of art, science, mathematics, geometry, history, and geography.3 Paper balloons play a role in Easter celebrations in the town of Leonidion on the east coast of Greece. On the eve of Easter, after the parish priest has uttered the words "Christ has risen," parishioners set aloft hundreds of paper fire balloons into the night sky. Paper historian Elaine Koretsky has documented the construction and flight of handmade paper fire balloons in Burma. \[See Koretsky's article in this issue. Ed.\] Perhaps the largest and most sophisticated paper hot-air balloons are made in Brazil and Argentina, where teams work for a year to design, engineer, and build balloons 50 to 100 feet in height to compete in annual June festivals.4 The envelope is made up of standard gores (panels of paper) except that each gore is made up of hundreds of pieces of colored paper, each individually cut and glued. This collage technique creates an envelope with complex and rich geometric patterns.5 The heat source for these balloons also involves the use of paper. Rolls of paper towels, those commonly used in kitchens, or rolls of toilet paper are soaked in paraffin and mounted to a platform made of wire that sits inside the balloon near the open neck at the bottom. Once ignited, the paraffin burns and provides the necessary heat until it expires and the balloon begins to descend. Sometimes the balloon crash-lands before its fuel is spent, raising the risk of fire. With safety in mind, the Brazilian government enacted a law in May 1998, forbidding the flying of these balloons. Fortunately for Argentineans, the art and craft of paper hot-air balloons still continues. summer 2006 - 17 Colorful, detailed Argentinean paper hot-air balloons. All photos on this page by and courtesy of Gabriel Krasnopolsky, Turma del Plata, Buenos Aires. 18 - hand papermaking Model Paper Hot-Air Balloon The model balloons I describe here require thin, lightweight paper that weighs about 15 grams per square meter. I use tissue paper, the kind available in dollar stores and card shops for gift-wrapping or used as filler when packaging clothes. While commercial tissue paper is adequate for this project, one can make a much stronger but more expensive balloon using thin Japanese papers such as gampi or kozo paper. The long bast fibers and the Japanese nagashizuki method of papermaking result in a material that is strong, lightweight, and flexible, qualities which make Japanese paper ideal for hot-air balloons. The explanation and drawings that follow describe a six-foot-high balloon. You can make a smaller version by simply halving all of the dimensions. Materials for Making the Balloon - 40 sheets of tissue paper, 20 x 26 inches each. You will also need an 8-inch-diameter circle to be used at the crown. Use the cut-offs to make this circle. - Stiff cardstock for making a template. - An adhesive paste or glue you would normally use to glue paper. Solid glue sticks work best. - A 30-inch length of wire for the bottom ring. A thin wire coat hanger works well. Materials for Launching the Balloon - A camp stove, a hair dryer, or industrial heat gun. If you use a camp stove for your heat source, you will also need an 18-inch length of 6-inch-diameter stovepipe. - An 8-inch length of string to make a loop at the top of the balloon. - A broom handle (or stick) with a hook on the end to support the balloon while it is being filled with hot air. summer 2006 - 19 Assembly Assemble the envelope of the balloon by gluing together the gores (panels). The gores can be decorated with permanent markers or can alternate in color. First make a template out of cardboard or stiff cardstock following the dimensions given in Figure 1. Make eight tissue-paper panels, each at least 96 inches long and 23 inches wide by gluing five sheets of tissue paper together end to end. Use a -inch overlap for the glue joint. Pile the eight sheets of paper on top of one another. Lay the template on top and, using a sharp cutting blade, cut through all eight sheets at once. Take two of the gores and lay one on top of the other, slightly offsetting the top gore to one side by of an inch (see Figure 2). Apply glue to the lower panel along the -inch margin and fold it over onto the top panel. Glue and fold immediately as you work along the length of the panel. Lay a third panel on top of the two just glued, but this time offset the panel to the opposite side (see Figure 3). Glue and fold as you did the first time creating an accordion fold. Continue in this manner until you have glued all eight gores. Check often to see if any of the panels are being glued in the wrong place. Now lift the unglued edge of the top (the eighth) panel and fold panels two through seven in half into the center leaving the edges of panels one and eight to be glued together like the rest, completing the circle (see Figure 4). Check once again that there are no areas glued that should not be. While the balloon is still folded, cut 1 inch off the crown. Tape a short piece of string to the 8-inch-diameter circle of paper creating a loop. Glue the circle to the top of the balloon to close the hole. Next make a hoop with the coat hanger wire, about 9 inches in diameter plus an overlap. Size the hoop by opening it inside the neck of the balloon an inch from the bottom of the gores. Remove the sized hoop and tape the overlap. Make eight tabs in the neck of the balloon by cutting 1-inch-deep cuts between each of the eight seams (see Figure 5). Secure the wire hoop in place by gluing and folding over the tabs. The wire hoop serves two purposes—to weigh down the bottom of the balloon so that it is more stable in flight, and to create an opening, making it easier to fill with hot air. Now inflate the balloon with hot air using a hair dryer or heat gun and repair any unglued seams or holes. This should be done indoors. Your hot-air balloon is now ready to launch! Launching Find a wide, open space to launch your balloon and make note of the wind direction. Seasoned balloonists will release a small rubber helium balloon to test the winds. Depending on the size and weight of the balloon, temperature, and wind conditions, you may have to chase the balloon for a couple of miles. The danger is that it may come down on a busy street or freeway or get caught in power lines. Choose an open field and only fly the balloon in very light wind. It can also be flown in a large auditorium for a more controlled flight. To fill the balloon, support the crown with the broom handle and secure the hook through the loop (see Figure 6). Place the stovepipe over the lit camp stove and lower the neck over the stovepipe. Fill with hot air until a distinct upward pull is felt. Then let go. The balloon will quickly ascend. The completed paper hot-air balloon, as described in this article, ready for launching.