10 BULLETIN 849, U. S. DEPARTMENT OF AGRICULTURE. 
plant of 23 stories as in a higher one. By either elevating or pump- 
ing the milk to a tank 2 or 23 stories high, gravity will do the work; 
that is, the milk will flow through the clarifier and the pasteurizer 
into the bottle-filling machinery without the use of a pump. 
The principal advantage of building a higher plant is the smaller 
ground area needed when the plant is in a thickly settled part of the 
city; however, the tendency to build farther away from the down- 
town section is increasing, so that this consideration becomes of 
minor importance. The appearance of the building from the street 
is important, as it serves as an advertisement. 
While the size of the plant as well as the number of stories de- 
pends on the quantity of milk to be handled, it should be so planned 
that one man can remain on one floor and not have to go from one 
floor to another in doing his work. Much time may be wasted if the 
men have to go upstairs and downstairs in their daily duties. 
The ceiling of the plant should be at least 12 feet high. When 
the pasteurizing equipment is on the balcony, midway between the- 
ground floor and the second floor, the handling room and the bot- 
tling room should be two full stories. 
MATERIALS OF CONSTRUCTION. 
The materials used for the construction of the plant depend a 
great deal on local conditions. The most satisfactory materials that 
may be used are reinforced concrete, hollow tile with cement finish, 
or selected brick. Cement blocks are also used to a limited extent. 
When concrete is used, the inside walls should be finished with a 
smooth surface and protected with paint that will stand hot water 
and steam. 
At present the proportion of brick plants and wooden plants is 
large, but concrete is becoming very popular in many localities and 
is probably the most suitable for a milk plant. It is practically fire- 
proof, very sanitary, weather resistant, and durable. Hollow tile 
with stucco finish is also much used for milk plants. With that 
type of construction the inside walls must be finished with cement 
or similar material.. In certain localities cement blocks are used. 
This form of construction is usually found in the smaller plants 
and is very satisfactory, provided the material is not too expensive. 
The wood-frame buildings in nearly all cases are old ones. Many 
plants are now built of selected brick with cement finish on the 
inside, which is a very satisfactory type of construction. 
INSIDE WALLS AND CEILINGS. 
For the inside walls select a material that will provide a smooth, 
easily cleaned surface that is durable and waterproof. Concrete or 
cement is very commonly used and is quite satisfactory. This ma- 
