In this report are described four different types of propellers which appeared at widely separated dates, but which were exhibited together at the last Salon de l'Aeronautique. The four propellers are the Chaviere variable pitch propeller, the variable pitch propeller used on the Clement Bayard dirigible, the variable pitch propeller used on Italian dirigibles, and the Levasseur variable pitch propeller.

This report is intended to cover the progress that has been made in both the manufacture and utility of light alloys in the United States since the first part of 1919. Duralumin is extensively discussed both as to manufacture and durability.

"If we wish to form an accurate idea of the extraordinary progress achieved in aeronautics, a comparison must be made of the latest altitude records and the figures regarded as highest attainable limit some ten years ago. It is desirable, for two reasons, that we should be able to define the limit of the altitudes that can be reached without artificial aid. First, to know to what extent the human body can endure the inhalation of rarified air. Second, the mental capacity of the aviator must be tested at high altitudes and the limit known below which he is able to make reliable observations without being artificially supplied with oxygen" (p. 1).

Methods and equipment for recording small and sometimes rapid motions by photographic means are described, and the efficacy of photographic recording in such instances is evaluated. The optical system consisting of the light source, the mirror or prism for transmitting motion to the emergent beam, and a means of bringing the rays into focus on the film are discussed. Attention is given to the critical issue of mirror mounting.

Given here are the results of experiments conducted by Colonel Costanzi of the Italian Army to determine the influence of the surrounding building in which a wind tunnel was installed on the efficiency of the installation, and how the efficiency of the installation was affected by the design of the tunnel. Also given are the results of a series of experiments by Eiffel on 34 models of tunnels of different dimensions. This series of experiments was started in order to find out if, by changing the shape of the nozzle or of the diffuser of the large tunnel at Auteuil, the efficiency of the installation could be improved.

Given here is a brief description of the Göttingen wind tunnel for the testing of aircraft models, preceded by a history of its development. Included are a number of diagrams illustrating, among other things, a sectional elevation of the wind tunnel, the pressure regulator, the entrance cone and method of supporting a model for simple drag tests, a three-component balance, and a propeller testing device, all of which are discussed in the text.

Note presenting an examination of horizontal buoyancy in wind tunnels, including an examination of the relative flow, static pressure gradient, horizontal buoyancy computation, and methods of computation in practical use are provided.

Describes the different varieties of clover, hay grasses, and regular grasses that are found in and best suited to meadow lands in the northeastern and midwestern United States; also explains methods of seeding and fertilizing.

Report discusses the theory of inflow of the propeller and the fact that both suctional axial velocity and suctional tangential velocity must be considered when calculating the maximum efficiency.

Patent for a funnel for heavy, slow running liquids, that will prevent any spilling when turned sideways.

Patent for an attachment for cars. This attachment reduces carbon deposit in the cylinder and on the valves of the car.

Patent for improved butter cutting machine to be used in professional kitchens.

Patent for a broom which allows the user to easily replace the broom straw or fiber with new straw or fiber when it is worn out. The intention is to decrease the cost of brooms while still producing "a strong and relatively durable broom structure" (lines 18-19).

Patent for automobile radiator with protective members for the water-containing chambers.

Patent for new and useful improvements for can openers. The principal purpose is to provide means for opening round cans of different sizes and also square cans.

Patent for an animal trap that allows an animal, most suitably animals of the rodent species, to enter a rectangular box from any of its four sides through a gate formed of downwardly inclined wires pivoted above each of said openings inside of the box. When an animal enters the trap, they are unable to leave because of the downwardly bent ends of transverse bars secured to the said inclined wires.

Patent for a wooden sugarcane stripper with two cutting blades that "reduces to a minimum the liability of damage being done to the stalks during the stripping operation" (p. 2, lines 21-24), including illustrations.

Patent for improvements in chairs and counters. This patent has to do with "mounting a chair with relation to a counter, table or the like, so that the chair can be slid to a position beneath the counter when not in use" (lines 9-13). This patent also has to do with moveable back and seat of the chair so that it can be folded when not in use.

Patent for a detachable bail (wire handle) for cans and buckets allowing bails and cans to be packed separately and reducing overall packing space.

This report provides results of analyses and pertinent fata regarding eleven samples taken from the composition of the air in burning buildings.

Patent for an electronic heating comb providing an electric heating element.

Patent for an improved inlet grate, which has a supporting frame. This inlet grate will not be displaced by traffic or other disturbances.

Patent for a wrench that has a fixed jaw and an adjustable slidable jaw.

Patent for Train-Order Holder designed to keep sheets of paper secure and in place to prevent writing on margins and displacement.