The Bridgeport times and evening farmer., 1920-01-05
HOW GREAT iS YOUR KNOWLEDGE
 O. A GALORE?
Flow the Housewife Gan Figure Out the Cheapest
 Efficient Body Fuel

Washington, D. C., Jan. 5 = "A . family consisting of father, mother, ] and three children requires about a hundred and twenty 190-caloEae portions for an adequate daily diet"
 How much would that have meant to the average housekeeper ten years ago? She probably could not have told whether calories were islands or canned goods" as MT. Dooley said of the Philippines. Lately, however, they have been talked and written about so much that she at least has a vague notion that they are in some way connected with the value of food to the body and that the more calo- ries she can provide for her family, the better it will be nourished. The United States Department of Agricu.- ture has recently published some tables which make it easier for her to 'count the calories'' as well as the cost of the food she buys. She can use such tables without knowing any thing more aout calories, just as she can use electric light without under standing the kilowatt hours that ap- pear in the monthly bill; but calories are neither so mysterious nor so com plicated that she can not easily un- derstand what they are.
 The word calorie comes from "ca- lor." a Latin word meaning heat. A calorie is a unit for measuring quan- titles of heat just as yard is a unit for measuG Gng length or pound for weight. Roughly, a calorie equals the amount of heat required to raise the temperature of a pound of water degrees F.
 Heat and Energy Similar.
 But that isn't the whole story. What we call heat and what we call energy are really different forms of the same force. The heat of the sun, the strength of the winds, the warmth from the fire, the pressure of the expanding steam or exploding gas in the engine, even the flowing of sap in the plant and the construction of the muscles in our bodfes-al these are due to the same universal energy showing itself in different ways. Coal is made up of substances held together by this same energy, and so Is gasoline or any other kind of fuel. When the fuel is burned, the energy is set free in the form of heat which in turn may become the force that drives the machine. In this last form we call it me chanical energy. Thus our calorie may represent either enough heat to raise the temperature of one pound of water degrees F. or enough me chanical force to lift one ton about one foot and a half.
 Now, food is fuel for our bodies and the energy stored in it can be re- leased in the body and used for keep ing 1t warm or for the work of the muscles, much as gasoline Is released and used when the gas is consumed FTNI, our muscles the more mechanical energy we release and the more must be provided by our food fuel. In or der to make sure that we are stok- ing our body engine rightly, we must be able to say both how much energy our food yields (called it's fuel or energy value) and how much energy our bodies use. This is where the calories come in, for we can measure both food energy and body energy in calories.
 Facts Simplified.
 How scientists have learned to do this is 8 really wonderful story in which famous men all over the world have been playing their parts for a century, marvelously accurate ap- paratus hase been developed and all sorts of interesting facts have been discovered. Thanks to it all, the scientists now really know what are the energy values of our common foods and what are the energy needs of all sorts and conditions of men And, best of all, they know these for merly mysterious things so we'll that they can make them of practical use to plain, everyday people who don't !. understand much about science.
 Heat and energy are sometimes q measured in other ways than by calo. -ries, just as weight is sometime. measured in kilograms instead ot pounds, and length in meters instead of yards. In questions of engin, fuel another and larger unit, called the British thermal unit, is usually more convenient than the calorie while in dealing with some types O 1Tlercha anical work, the unit called tht foot ton is often used. But for ques tions of human food and body en ergy, the calorie is almost universal, chosen as the most satisfact ctory meas ure. Sometimes when the naateria measured yields so many calories tha we have to discuss them in tens o thousands. the 100-calorie portion i used instead, just as dollars are use, instead of cents in reckoning prices This 100-calorie portion means simpl the amount of a given food whicl would yield 100 calorieS of energy.
 Thus we find that the sentenc at the beginning of this story reall does mean somthing. It means tha the family described in it probabl uses up body energy at the rate 0 about 12,000 caiories a day and need food fuel of the same energy value.
 Choosing Cheap Fuel.
 Body-fue1, like other kinds of fue costs money and the problem is t get the amount needed for the small est sum possible, which means choos ing food rather carefully. A ma running a sawmH1 in the cypres swamps of Louisiana or the Michiga woods would have to pay lot C money for enough anthracite coal t run his steam engine, but he ca take his fuel from the sawdust hea and the slab-Iine, and so save mone,
 Much the same situation exist with regard to the fuel for the hu
 man engine. If our family of fiv bought it's 120 10O-calorie portion all in sirloin steak at 50 cents
 pound, the cost would be s6 a da, If it bought them all in white DC