CO-OPERATIVE FACTORIES. 1 27 



If the walls be made of wood, there should be at least 

 two still air spaces in the wall, made of five thick- 

 nesses of lumber and at least three of good building 

 paper. These spaces should be made tight at the top 

 and bottom so that the air in them cannot circulate. 

 In the case of refrigerators and well made .cheese 

 ripening-rooms there should be in addition a six inch 

 space filled with dry sawdust, mill shavings, or tan 

 bark. It is also a good plan to confine the air of the 

 wall in refrigerators in small spaces by nailing inch 

 strips between the sheeting in such a way as to form 

 squares from one to two feet in size. 



The best inside finish for a brick, stone, or cement 

 building is the wall, without any lumber except on 

 the ceiling. The walls and ceiling should be white- 

 washed as often as needed in order to keep it clean. 

 A spray pump may be used for the purpose. A lath 

 and plaster finish is not suitable for a factory, as the 

 plaster becomes loosened by the jar of the machinery 

 and by the steam and soon falls and disfigures the 

 inside. The ceiling of the work-room in a creamery 

 or cheesery should not be less than twelve feet high. 

 This makes the room much cooler in summer and 

 more healthful at any time, though somewhat more 

 difficult to heat in winter. The heating of all parts 

 of the building should be done from the steam boiler. 

 By arranging for the condensed steam to return to the 

 boiler the expense is not very great, and it saves the 

 expense, risk, and trouble of stoves. For each twenty 

 cubic feet of space to be heated, one linear foot of 

 inch pipe is needed. A room thirty by thirty by 



