UTAH ACADEMY OF SCIENCES 71 
the sun. That is; there should be the application of 
radiant heat, of convected heat, and all the variations 
of temperature and humidity found in a solar day. The 
material is allowed to “sleep” between periods of dehy- 
dration. The machine designed to accomplish this is 
one in which air is dehydrated to the proper humidity by 
being passed through a spray of brine, then heated to 
the proper temperature, then passed into separated cells 
containing stacks of trays of the material to be dried. 
There are dampers in these cells so arranged as to direct 
the currents of air intermittently through the different 
parts of the stack. 
No. 3, patented in 1917. The operation of this 
machine is based on the theory that, first, if a cellular 
body is heated, the cell fluid expands, forcing the cell 
wall to expand; the cell wall in expanding becomes 
thinner thus allowing more rapid exmosis of the cell 
fluid; second, when this exuded water is removed by 
heated air currents the process of evaporation lowers 
the temperature of the cell to the point where exmosis 
ceases; third, light, in the form of electric light, aids in 
the exmosis of water from plant cells. This idea was 
worked out in a machine composed of a revolving drum 
made of compartments in which the material to be dehy- 
drated is placed. Through the center of the drum run 
steam or electric coils which heat the material to 110 
degrees F.; after the material reaches this temperature 
the air currents are forced through the compartments. 
Electric lights are so placed as to illuminate the drying 
material. The steam coils in the center of the drum 
keeps the material heated up to proper temperature. 
No. 4, patented in 1917. This machine was designed 
to dry hops and is operated on the theory that materials 
dry more uniformly and that there is less physical or 
chemical change in the cells when the temperature of 
convected heat starts at 120 degrees F. and is raised at 
intervals until it reaches 170 degrees F. In this way 
the material is dried to such a low moisture content that 
there is not enough moisture to allow the enzymes to 
become active, but there is still enough left to protect the 
oils from rapid oxidation, as would happen if the mater- 
ial were to be dessicated. 
