Remember when panhandlers used to ask for a dime for a cup of coffee?

You can wrap that line in pink ribbon and deliver it to the National Archives for filing. It's just a memory now.

A few days ago. I told you I had experimented with coffee beans and instant coffee to find out how many ounces of beverage each yielded. After that column appeared. James R. Morrell suggested that I check the Feb. 7 issue of U.S. News and World Report, which carried a summary of a study by the Department of Agriculture.

Agriculture's researchers assumed that "one cup" contains six ounces, and that a pound of ground coffee beans makes 50 cups of beverage. With "name brand" coffee selling at $3.19 a pound, the cost of brewing cup of coffee at home was calculated to be 6.4 cents. Using "store brand" coffee at $2.39 a pound would bring the price down to 4.8 cents a cup.

However, with a 10-ounce jar of name brand instant selling at $3.39 and yielding 142 cups of coffee, the survey found that instant coffee costs only 2.4 cents a cup. The magazine's listing makes no mention of store brand instants that are often just as good, and a lot of cheaper.

It does, however, note that an 8-ounce jar of freeze-dried instant (supposedly much tastier than regular instant) sells for $4.79 and produces 120 cups of coffee at an average price of 4 cents a cup. My own experience has been that once you depart from the ritual of grinding your own coffee beans each morning, you are beginning to make compromises that can end up out in left field if you permit them to. Your own taste and pocketbook have to guide you to a warm morning drink you can live with.

Among the "other beverages" that Agriculture looked into was hot chocolate, which to my mind is not a very good substitute for coffee. It is also more expensive than coffee. It will run you from 6.8 to 10.5 cents per cup.

A more practical suggestion may be Postum, a beverage made from cereal and therefore totally lacking in caffeine - with means it is also totally lacking in coffee-like taste. However, you can buy 8 ounces of Postum for $1.55, the Agriculture Department found, and make 68 cups of beverage with it. The cost per cup is therefore only 2.3 cents.

Tea is even cheaper, especially when a teabag is used for one or more refills. A cup of tea made from name brand teabags costs only 2 cents (8 ounces of teabags produce 100 cups and cost $1.95). You can save even more by buying store brand teabags or loose tea. Either runs $1.39 in 8-ounce lots and brings the cost of a cup of tea down to 1.4 cents. Instant tea also runs 1.4 cents a cup. Three ounces cost $1.69 and produce 120 cups of tea.

To some people, Agriculture's research will be of little interest. They will continue to buy their favorite brands of coffee, even if the price goes to $5 or $6 a pound.

But many District Liners, particularly those who must live on fixed incomes, have already been priced out of the coffee market. More will be forced to drop out as the price continues to increase. They're as addicted to the taste and aroma of coffee as any of us, but to survive they must find ways to cut costs. I hope there's something in the foregoing they'll find of help.

Meantime, the 10-cent cup of coffee appears to be a thing of the past.The prices cited in Agriculture's study include ingredients only. They do not cover the full cost of brewing a cup of coffee, whether at home or in a restaurant - things like energy, coffee-making apparatus, crockery, silverware, cream, suger or dishwashing. If you're a restaurateur, add labor, rent, insurance, breakage, theft and 19 kinds of official permits.

If you're among those who are forced to compromise because you can no longer afford real coffee, may be this will make you feel better: I have found that if you drink tea hot enough, it burns your mouth and you can't be sure whether you're drinking tea or coffee. Keep smiling.