2 BULLETIN 565, U. S. DEPARTMENT OF AGRICULTUEE. 
a lower grading and a reduced price for the good eggs he has 
shipped. The shipper who does not candle his eggs has no check on 
the candling reports of the consignee and must accept loss off, 
lowered grading, or other price penalties. 
Knowledge of candling and sorting sufficient to sort eggs by the 
various commercial grades used in the central markets is, of course, 
a valuable asset to the country collector and shipper. Ability to use 
the candle at least with accuracy enough to exclude inedible eggs is 
becoming an accomplishment essential to all who wish to escape legal 
difficulties and to market their produce on anything like a profitable 
basis. The detailed descriptions, diagrams, and colored plates in 
this bulletin, it is believed, will enable producers, dealers, and house- 
wives to distinguish with sufficient accuracy between edible and 
inedible eggs. The authors caution those who are first attempting 
to candle for market to give the benefit of the doubt to the consumer 
and to retain for home use any eggs which appear at all questionable 
before the candle. 
GRADING OF EGGS. 
Eggs are graded for market according to freshness, cleanliness, 
size, color, and soundness of shell. Sorting according to size, color, 
and cleanliness requires only a visual inspection of the egg while it 
is being held in the hand. At the same time eggs clearly showing 
damaged shells may be separated. "When the crack is so small that 
it is not easily seen with the naked eye, it can be detected by candling 
or by clicking two or more eggs together. A cracked egg tapped 
lightly against a whole egg gives out a deadened sound, quite differ- 
ent from the clear ring from eggs with unbroken shells. It is com- 
paratively easy to grade eggs according to appearance and soundness 
of shell, but it requires knowledge and experience to be able to judge 
the quality of the contents by candling. 
THE EGG CANDLE. 
The only equipment necessary for candling eggs is a device which 
consists of a bright light surrounded by a shield having a small open- 
ing of sufficient size to receive the egg. Farmers who have few eggs 
to market can make a candle by using a kerosene lamp as a source of 
light and a piece of stovepipe about 8 inches long as a shield. The 
hole should be 1| inches in diameter and should be cut in the pipe 
just opposite the flame in the lamp. Notches, or small openings, 
should be cut in the bottom of the pipe opposite the hole, to provide 
air for the lamp. A candle similar to that just described is shown 
in figure 1. 
