Describes different types of irises, and methods for growing them successfully in a home garden.

The object of this report is the description of a method which seems to be practicable for determining the path of an airplane, especially in taking off and landing. This report tells how, by means of a camera, preferably a kinetograph, which simultaneously photographs a stop watch the distance of an airplane from the camera and its height above the ground can be determined.

Now that the two-stroke-cycle engine has begun to make its appearance in automobiles, it is important to know what services we have a right to expect of it in aeronautics, what conditions must be met by engines of this type for use on airplanes and what has been accomplished.

"We propose to show how to calculate the cooling capacity of all radiators through which the air flows in separate streamlets, whether enclosed in actual tubes or not and whatever cross-sectional shape the tubes may have. The first part will give the fundamental principles for calculating velocity of air in the tubes and the heat exchange by radiation, conduction and convection, and show, by examples, the agreement of the calculation with experiments. In the second part, the effect of the dimensions and conditions of operation on the heat exchange will be systematically investigated" (p. 1).

"The following report has been prepared for publication by the NACA. Suitable locations of orifices for the measurement of pressure distributions have been discussed. Tables are given for quickly laying out these locations and for quickly and easily computing the resultant air forces from the result of the measurements" (p. 1).

The Behm acoustic sounder for aircraft enables the barometric determination for the altitude by night or fog and therefore promises to prove of great importance in safeguarding air traffic.

"Through the utilization of the "Magnus effect" on the Flettner rotor ship, the attention of the public has been directed to the underlying physical principle. It has been found that the Prandtl boundary-layer theory furnishes a satisfactory explanation of the observed phenomena. The present article deals with the prevention of this separation or detachment of the flow by drawing the boundary layer into the inside of a body through a slot or slots in its surface" (p. 1).

The public generally is taking very little interest in the progress of Civil Aviation, and the time has come to educate the public in aeronautics and to make them realize the far-reaching importance of air transport. Briefly, the whole problem resolves itself into discovering and applying means for bringing some of the many aspects and effects of civil aviation into the everyday lives of the public. The report suggests three principal groups of methods: (1) Bring aviation into daily contact with the public. (2) Bring the public into daily contact with aviation. (3) General publicity.

This report, on the planing and get-away characteristics of the F-5-L, gives the results of the second of a series of take-off tests on three different seaplanes conducted by the National Advisory Committee for Aeronautics at the suggestion of the Bureau of Aeronautics, Navy Department. The single-float seaplane was the first tested and the twin-float seaplane is to be the third. The characteristics of the boat type were found to be similar to the single float, the main difference being the increased sluggishness and relatively larger planing resistance of the larger seaplane. At a water speed of 15 miles per hour the seaplane trims aft to about 12 degrees and remains in this angular position while plowing. At 2.25 miles per hour the planing stage is started and the planing angle is immediately lowered to about 10 degrees. As the velocity increases the longitudinal control becomes more effective but over control will produce instability. At the get-away the range of angle of attack is 19 degrees to 11 degrees with velocities from the stalling speed through about 25 per cent of the speed range.

Equations for instantaneous velocity and distance flown are derived for an airplane which crosses the starting line of a speed course at a speed higher than that which can normally be maintained in horizontal flight. A specific case is assumed and calculations made for five initial velocities. Curves of velocity, average velocity, and distance flown are plotted against time for each case and analyzed. It is shown that the increase in average velocity due to a diving start may be very large for short-speed courses.

Detailed tables of pressures and densities are given for altitudes up to 20,000 meters and to 65,000 feet. In addition to the tables the various data pertaining to the standard atmosphere have been compiled in convenient form for ready reference. This report is an extension of NACA-TR-147.