BEFORE SCALES were used in determining meat prices, the ancient Romans arrived at the price by a game of chance. The buyer would shut one of his hands. The seller did the same. Each of them suddenly opened their full hand or a few fingers. If the fingers were even on each side, the seller had the price he offered; if they were odd, the buyer gave his own price.

This process was suppressed in about the year 360. The government felt that it was for the public good to suppress this measuring practice for the sale of meat, and that it was more advisable to sell by weight than to trust to a game with fingers.

By the Middle Ages, the governments were even more aggressive about the relationship between weights and prices at point of sale. Selling underweight loaves of bread was a common crime and bakers selling short weight loaves were pulled through the town on a hurdle with the offending loaves hung around their neck. This long trend of consumer protection by governement is now in doubt. It's time once again to have your own scale, not only for a control of what you are paying for your food, but as an accurate method of measurement.

Measuring ingredients by weight is much more precise than measuring by volume. A pound of flour will always contain the same amount of that component. A cup of flour can vary enormously between flour that has been sifted into the cup or packed down tightly. A request for "One pound of onions" is exact, "eight medium onions" is not. European cookbooks measure solid ingredients by weight, American cookbooks use volume.

For many years, scales were not common pieces of kitchen equipment of this side of the Atlantic. Today, however, with our increased interest in diet control, scales are becoming a basic kitchen utensil. After all, measuring "a cup" of halibut for broiling is not only non-specific but could really kill the presentation of the finished dish. A "two ounce filet" isn't much to eat, but it is exact.

Kitchen scales are divided into two basic designs: the spring scales and the beam balance.

A beam balance works in precisely the same way as a doctor's scale.Terraillon, an excellent French manufacturer of measuring instruments, produces a beam balance 12-by-7 inches at the base and 3 inches high. The base is made of colored enameled steel and comes with a removable, highly polished chrome holding tray. There are two rows of slide balances and counter weights. The upper level will measure up to 22 pounds. The lower slide records ounces. It is quite accurate throughout its full measuring range and a good value at $36.

Terraillon also makes a compact spring scale. Made of plastic and only 6 1/4-by-4 1/4 inches at the base and 4 1/2 inches high, it is not as accurate as a balance but will do a decent job for almost all kitchen chores.

Spring scales work like bathroom scales. The weight in the tray presses down on a spring which transmits the pressure to a calibrated dial.As springs age, they tend to be less precise. But the convenience of this scale makes it a good choic for most kitchens. Available in 2,000 gram and 4,000 gram capacities, they retail for $23 and $25 respectively.

Many restaurants use a professional quality scale made by Pelouze. It has an excellent system for adjusting the scale for each portion. Place a bowl or dish on top of the scale to hold the ingredients. There is a large, clearly printed, unbreakable, plastic dial that is set back to zero. You add your first component, check its weight and turn the dial back to zero again. Continue measuring in this manner until all the ingredients have been prepared. Made of enameled steel, it will measure up to 25 pounds at one time. The base is 6 1/2-by-6 1/2 inches. It is 8 1/2 inches high and sells for $31.95.

One auxiliary feature worth noting is the aluminum Adapto-Plate.It measures 18-by-14 inches and is just like a baker's sheet. The plate attaches on the top of the scale's measuring platform. It will allow you to accurately measure large objects. The Adapto-plate distributes the weight and assures a more accurate reading. The plate costs $16.95. If you've ever wondered whether the 18 pound turkey that comes home from your butcher really weighs 18 pounds, this is the scale for you.