UNITED STATES DEPARTMENT OF AGRICULTURE 
BULLETIN No. 494 
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Contribution from the Bureau of Plant Industry 
WM. A. TAYLOR, Chief 
Washington, D. C. 
PROFESSIONAL PAPER 
January 16, 1917 
A HUMIDIFIER FOR LEMON CURING ROOMS. 
By A. D. Shamel, 
Physiologist in Charge of Fruit-Improvement hvvestigations, Office of Horti- 
cultural and Pomological Investigations. 
CONTENTS. 
Introduction 
Object of the experiments 
Plan of the work 
Methods tried for increasing the relative hu- 
midity 
The invention of the humidifier 
Page, 
Construction of the humidifier 6 
Operation of the humidifier 7 
Other uses of the humidifier 9 • 
Results 10 
Summary 10 
INTRODUCTION. 
In the summer of 1914 the writer became interested in some studies 
having for their object the control of humidity in the curing rooms 
of one of the lemon packing houses in southern California. These 
rooms, 20 in number, are about 20 feet long by 20 feet wide and 10 
feet high. They are arranged five on each side of two corridors, 
which are covered by monitor-type ventilators with slatted sides. 
The rooms are equipped with ventilating doors along the outer bot- 
tom side and inner top side, arranged in such a way that they can be 
opened easily and held in any position desired, or can be closed so as 
to prevent any appreciable movement of air from th^ rooms. 
The walls of the rooms are made of galvanized steel. A 4-inch 
space between the walls, on all sides of the room except the bottom, 
is filled with redwood sawdust. The floors of the rooms are made 
of 2 by 4 inch wooden stringers laid flatwise on the joists, with half- 
inch spaces betAveen them. I^nderneath each room is a small earth 
cellar, or pit, in which to place heating appliances for use in raising 
the temperature of the rooms. 
Gr,990^— 17 
