By the 1920s, each state in the United States had passed public laws that stipulated a certain day to be Arbor Day or Arbor and Bird Day observance.

By the late 1920s Potter and her Hill Top farm manager Tom Storey had made a name for their prize-winning Herdwick flock.

By the 1920s, composers of Tin Pan Alley and Broadway used ballad to signify a slow, sentimental tune or love song, often written in a fairly standardized form ( see below ).

By the late 1920s, New York writers other than Fitz Gerald were starting to use " Big Apple " and were using it outside of a horse-racing context.

By the 1920s, the emerging middle and working classes were powerful enough to elect a reformist president, Arturo Alessandri Palma.

By the 1920s, many newspapers had a comics page on which many strips were collected together.

Additional milieu were provided by Chaosium with the release of Dreamlands, a boxed supplement containing additional rules needed for playing within the Lovecraft Dreamlands, a large map and a scenario booklet, and Cthulhu By Gaslight, another boxed set which moved the action from the 1920s to the 1890s.

By the early 1920s, unit operations became an important aspect of chemical engineering at MIT and other US universities, as well as at Imperial College London.

By the late 1920s, Al Capone and the Mob were inspiring not only fear, but piquing mainstream curiosity about the American underworld.

By the 1920s, the U. S. reached what is still its era of greatest-ever output, producing an average of 800 feature films annually, or 82 % of the global total ( Eyman, 1997 ).

By the 1920s Lewis Fry Richardson's interest in weather prediction led him to propose human computers and numerical analysis to model the weather ; to this day, the most powerful computers on Earth are needed to adequately model its weather using the Navier – Stokes equations.

By the 1920s, the idea of an Israelite conquest of Canaan-the story of the book of Joshua-was not supported by the archaeological record.

By the 1920s, Hearst, was the owner of a chain of newspapers from coast to coast.

By the 1920s, the diatonic harmonica had largely reached its modern form.

By the 1920s however the Senate had lost much of its original influence, and hence no sitting senator had been known to have serious aspirations of becoming prime minister whilst remaining in the Senate.

By the 1920s the number of cars had soared to 60, 000.

By the early 1920s, however, the inherent limitations of this type of engine had rendered it obsolete, with the power output increasingly going into overcoming the air-resistance of the spinning engine itself.

By the 1920s psychoanalysts assumed that homosexuality was pathological and that attempts to treat it were appropriate, although psychoanalytic opinion about changing homosexuality was largely pessimistic.

By the late 1920s the resistance movement against colonial rule had gathered widespread support during the mistreatment of the Samoan people by the New Zealand administration.

By the late 1920s, however, those employing only optical and electronic technologies were being explored.

By the late 1920s, economic performance had stabilised, but the overall situation was disappointing, for Britain had clearly fallen behind the United States and other countries as an industrial power.

By the 1920s, however, this boisterous folksiness had diminished.

By the end of the 1920s Corbusier was already an internationally known architect.

By the 1920s, the British Government were seeking a replacement for their book code systems, which had been shown to be insecure, and which proved to be slow and awkward to use in practice.

" By the 1920s, Birmingham was the 19th largest city in the U. S and held more than 30 % of the population of the state.

By monitoring, we mean some system of control over the types of information sent from the various centers.

By the use of various weights, data for a force-rate of shear graph can be obtained.

By means of charts showing wave-travel times and depths in the ocean at various locations, it is possible to estimate the rate of approach and probable time of arrival at Hawaii of a tsunami getting under way at any spot in the Pacific.

By making comparisons across cultural traditions ( time-based ) and cultural regions ( space-based ), anthropologists have developed various kinds of comparative method, a central part of their science.

By the end of the 14th century, most of Anatolia was controlled by various Anatolian beyliks.

By the mid-4th century however the assembly's judicial functions were largely curtailed, though it always kept a role in the initiation of various kinds of political trial.

By the early 2000s ( decade ), however, the university quietly reexamined its position on accreditation as degree mills proliferated and various government bureaucracies, such as law enforcement agencies, began excluding BJU graduates on the grounds that the university did not appear on appropriate federal lists.

By 1000 BC ancient civilizations were using technologies that formed the basis of the various branches of chemistry such as ; extracting metal from their ores, making pottery and glazes, fermenting beer and wine, making pigments for cosmetics and painting, extracting chemicals from plants for medicine and perfume, making cheese, dying cloth, tanning leather, rendering fat into soap, making glass, and making alloys like bronze.

By calculating the maximum time that electrical signals can move in various branches of a CPU's many circuits, the designers can select an appropriate period for the clock signal.

By studying categories and functors, we are not just studying a class of mathematical structures and the morphisms between them ; we are studying the relationships between various classes of mathematical structures.

By late 1918, hundreds of Cheka committees had been created in various cities, at multiple levels including: oblast, guberniya (" Gubcheks "), raion, uyezd, and volost Chekas, with Raion and Volost Extraordinary Commissioners.

By starting with an inertial frame, where Newton's laws of motion hold, and keeping track of how the time derivatives of a position vector change when transforming to a rotating reference frame, the various fictitious forces and their forms can be identified.

By March 1963 however, after the visit of Colonel Michael Greene of the United States Army, and the resulting ' Greene Plan ,' the pattern of bilaterally agreed military assistance to various Congolese military components, instead of a single unified effort, was already taking shape.

" By various stratagems the jealous king seeks his death, but the plots only endear David the more to the people, and especially to Saul's son Jonathan, who loves David ( 1 Samuel 18: 1, 2 Samuel 1: 25 – 26 ).

By late September 1945 the Thomases had left Wales and were living with various friends in London.

By July 2008 various blogs referred to " an e-mail " from a colleague of the band's attorney that suggested the issue was " amicably resolved ".

By comparing the length and intensity of various methods of therapies, it was proven that intensity is a better predictor of recovery than the method of therapy used.

By 1874 or 1875 ( various sources give both dates ) he had also perfected the electromechanical hardware to transmit his code.

Despite the revivalists ' various political views and different opinions regarding the nature of authentic folk music, they all shared an understanding of Americanism that grounded the nation's identity in cultural pluralism and political democracy " By the end of the 1930s they along with the musicians and others had turned American folk music into a social movement.

By far the most common and widespread species of fox is the red fox ( Vulpes vulpes ), although various species are found on almost every continent.

By 1947, Hayek was an organizer of the Mont Pelerin Society, a group of classical liberals who sought to oppose what they saw as socialism in various areas.

By 2006, such was the confusion from these multiple Acts, each amending the others ( and not all of which were ever actually commenced and thus were in the public record but not enforced as actual legislation ); and the amendments of Irish firearms legislation by other Acts ranging from the Wildlife Acts ( mostly relating to hunting law ) to the Road Traffic Acts ( relating to how and where firearms could be transported ) and others ; the large amount of secondary legislation ( Statutory Instruments, which set out regulations, the design of application forms for licences and so forth, as well as the details of when various parts of the Acts came into force ); as well as the introduction of EU firearms law into the canon of Irish legislation ; led the Irish Law Reform Commission to recommend that all the extant legislation be restated a legal process by which all the existing primary and secondary legislation would be read as one and a single document produced as the new Firearms Act ( and all prior Acts would be repealed ).

By the time of the Crusades ( 1096 – 1270 ), horseshoes were widespread and frequently mentioned in various written sources.

By the 19th century, the various forms and divisions of historic games began to differentiate and coalesce into the individual sports defined today.

By 16 May, however, Dannatt announced that Prince Harry would not serve in Iraq ; concerns included Harry being a high-value target ( as several threats by various groups had already been made against him ) and the dangers the soldiers around him would face should any attempt be made on the Prince's life or capture.