This section is from the book "The Steward's Handbook And Guide To Party Catering", by Jessup Whitehead. Also available from Amazon: Larousse Gastronomique.
Chickens lose one third their weight in boiling and one third more in picking from the bones and mincing. 4 1/2 raw chicken yields only 1 1/2clear meat for salad. "The result of a set of experiments which were actually made in a public establishment. They were not undertaken from mere curiosity, but to serve a purpose of practical utility: 2S pieces of beef weighing 2S0 lbs. lost in boiling 73 lbs. 14 oz. Hence the loss of beef in boiling was 26 1/2. in 100 lbs.; 19 pieces of beef weighing 190 lbs. lost in roasting 61 lbs. 2oz., or 32 lbs. in 100 lbs.; 9 pieces of beef weighing 90 lbs. lost in baking 27 lbs., or 30 lbs. in 100 lbs.; 27 legs of mutton weighing 260 lbs. lost in boiling and by having the shank-bone taken off 62 lbs. 4 oz. (the shanks weighed 4 oz. each.) The loss in boiling was 55 lbs. 8 oz.; the.legs of mutton lost 21 1/3. in 100 lbs.; 35 shoulders of mutton weighing 350 lbs. lost in roasting 109 lbs. 10 oz.; loss of weight in roasting shoulders of mutton is about 31 1/3. in 100 lbs.; 16 loins of mutton weighing 141 lbs. lost in roasting 49 lbs. 14 oz.; loins of mutton lose by roasting about 35 1/2. 100 lbs.; 10 necks of mutton weighing 100 lbs. lost in roasting 32 lbs. 6 oz.
From The Foregoing Statement Two Practical Inferences May Be Drawn: (1) In respect of economy that it is more profitable to boil meat than to roast it. (2)-Whether we roast or boil meat it loses by being cooked from one-fifth to one-third of its whole weight".