So you've left your umbrella in the subway again on a wet Washington day. Duck into the nearest drugstore and buy a cheap one, courtesy of this small island, now the umbrella capital of the world.

Thousands of young men and women here have become so adapt at rapidly fitting delicate steel ribs into waterproof fabric, and for such little pay, that Taiwan has overtaken Japan as the leading umbrella maker - and captured more than 60 per cent of the U.S. market in the process.

In the office of umbrella tycoon T. F. Chen - who is rarely without the black collapsible model he makes for Totes Inc. of Ohio - framed Chinese saying proclaims: "The heavens bestow great happiness" Chen won't deny it.

"Business is up 35 per cent over last year," he said. Even if there's drought in San Francisco and Hong Kong, it's pouring in Washington and Paris, and Chen's five-company Fu/Tai umbrella group sells umbrellas all over the world.

"There are so many umbrella factories in this country," he said, "and that much competition is good for quality and fashions. Before, many countries bought from Japan and West Germany, but now they don't make so many any more. Making umbrellas depends on manual labor. Taiwan's labor costs have risen some, but they are still lower than other countries."

In the same way. Taiwan has surged in the U.S. markets for shoes and tennis rackets. Chen raised salaries 25 per cent for his 1,000 workers last year, but they still average no more than $30 a week. They turn out about 3.6 million umbrellas a year about 1 million of which Chen sells in the United States.

About 850,000 of those are the basic black, collapsible model - what the industry calls "topless." The Totes company of Loveland, Ohio, pioneered the popular model that folds into a footlong tube businessmen can stuff in a briefcase. Totes found, however, that it could not make a profit paying U.S. wage rates for the delicate handwork. So its factories now concentrate on making overshoes while Chen and other overseas suppliers make the umbrellas.

Taiwan produced about 60 million umbrellas in 1976, and expects to do better this year. The demand in the United States and Europe hasn't increased sharply, but there's an umbrella boom in the Third World.

"African countries like Nigeria didn't want umbrellas before, now they do," Chen sai. "They used to go barefoot, but now they're wearing shoes. They're wearing better clothing now that they don't want to get wet."

Tastes in style and color vary all over the world. Americans seem to prefer conservative patterns and colors now - the bell-shaped clear plastic models have died out. Europeans like geometric designs while Southeast Asia goes for wild patterns and bright colors.

Chen's industrial empire consists of four factories lined up along a road in Wukou, a Taipei suburb. A huge water tower painted to look like an umbrella dominates the semi-rural scene. The first factory manufactures the steel tubes and ribs for the frame. The seconds turns out the nylon covers. The third factory makes handles and the fourth puts all the pieces together. A fifth company handles exports.

Company designers say they have pondered long and hard the lament of the customer who finds his umbrella blows inside out in a strong wind or is constantly lost. Chen says as umbrella that could resist the strongest winds would be too heavy. Many manufactures here are adding loops to handles to help absent-minded customers, who must still remember to put the loop over their wrist to keep from losing the umbrella.

Chen, 57, stumbed into the umbrella business after being refused admission to universities that were the preserve of Japanese and elite Taiwanese during the island's long period of Japanese occupation. He started to import umbrella parts from Japan, then opened a little workshop in a poorer section of Taipei in 1953 with $1,300 in savings. He pitched in to learn how to make an umbrella, with the help of his first nine workers. The business grew, spurred on by Chen's energy and attention to quality.

Today, he is chairman of the Taiwan Umbrella-Makers' Association, responsible for keeping the industry ahead of its rising competitors in Hong Kong and South Korea. Taiwan has suffered from it success. Its rise at a 71 per cent share of umbrella exports to the United States caused it to lose its duty-free status, forcing it to pay a 20 per cent duty that other Asian competitors still avoid.

Chen says he still finds a little time for his favorite pasttime, golf.And if it rains, says company manager H.C. Wu, "he's not upset. He just brings his umbrella."