Now showing items 13-32 of 115

    • Dates of Easter for Two Thousand Years 

      Rigge, William F., S.J. (1907)
      First Paragraph: | Whenever we take up the calendar of a new year our first inquiry is concerning the date of Easter, since its position regulates the dates of all the movable feasts of the year. This is as it ought to be.
    • The Demon Star 

      Rigge, William F., S.J. (1913)
      First Paragraph | In the northern heavens, visible in the United States on almost any night of the year, there is a famous star that the Arabians named Al Gol, the Demon Star. While all the myriads of fixed stars glowed ...
    • Does the Earth Really Go Round the Sun? 

      Rigge, William F., S.J. (1915)
      First Paragraph: | Deep down in the recesses of some minds, there may be perhaps a lurking suspicion, that the earth’s going around the sun at the distance of about 93,000,000 miles may be, after all, only a theory, and ...
    • Double Star Systems 

      Rigge, William F., S.J. (1913)
      First Paragraph: | The continual increase in the number and size and perfection of astronomical instruments, together with the progress in the skill of men that use them and study and measure and discuss their results, are ...
    • The Driving Clock and the Clamp and Slow-Motion Screw of an Equatorial 

      Rigge, William F., S.J. (1912)
      First Paragraph: | Providing an equatorial telescope with an efficient driving clock, and bringing the clamp and slow-motion screws on both axes down to the eyepiece, appear to be so exclusively the work of a professional ...
    • The Eclipse Expedition of the Creighton University to Washington Georgia 

      Rigge, William F., S.J. (1901)
      First Paragraph: | Creighton University has contributed its share towards the scientific observation of the total solar, eclipse of May 28, 1900, so far as its means and circumstances permitted. As this great event occurred ...
    • The Eclipses of 1905 

      Rigge, William F., S.J. (1905)
      First Paragraph: | Of the two solar and two lunar eclipses occur ring in the course of the year 1905, one of each class will be more or less visible in the United States.
    • The Eclipses of 1906 

      Rigge, William F., S.J. (1906)
      First Paragraph: | During the year 1906 there will be three partial eclipses of the sun and two total eclipses of the moon. One of each class will be visible in the United States.
    • The Eclipses of 1908 

      Rigge, William F., S.J. (1908)
      First Paragraph: | During the year 1908 there will be three eclipses of the sun. The first of these will occur on January 3, and will be visible to a part of the United States near the time of sunset. The second will take ...
    • The Eclipses of 1909 

      Rigge, William F., S.J. (1909)
      First Paragraph: | During the year 1909 there will be four eclipses, two of the sun and two of the moon. All of these, except one solar eclipse, will be more or less visible in the United States.
    • The Eclipses of 1916 

      Rigge, William F., S.J. (1916)
      First Paragraph: | There will be five eclipses during the year 1916. The first three will be completely visible all over the United States, the fourth can be seen only in Australia and its adjacent waters, while the fifth, ...
    • Edward Heis 

      Rigge, William F., S.J. (1906)
      First Paragraph: | The centenary of the birth of a great astronomer naturally calls for some notice of the man and his work. | Edward Heis was born in Cologne, Germany, on February 18, 1806. He was the third son of George ...
    • Envelope Rosettes 

      Rigge, William F., S.J. (1920)
      First Paragraph: | One way of drawing a cardioid is to make a pen start in phase 90° from the center of a disk and move along a radius with simple harmonic motion, while the disk revolves with a uniform angular speed of ...
    • Experimental Proofs of the Earth’s Rotation 

      Rigge, William F., S.J. (1913)
      First Paragraph: | In establishing the truth of the Copernican system, professors of astronomy are apt to look upon Foucault’s pendulum as the one experimental proof of the earth’s diurnal rotation. They may also possibly ...
    • Father Angelo Secchi 

      Rigge, William F., S.J. (1918)
      First Paragraph: | A century ago, on June 29,1818, there was born at Reggio in AEmilia, Italy, a child that was destined to become one of the greatest astronomers of his age. He was to open up new avenues of research and ...
    • Father Hagens Astrophotographic Journey 

      Rigge, William F., S.J. (1907)
      First Paragraph: | It was in the early part of April, 1906, that Father Hagen took his departure from the Georgetown College Observatory in order to obey the summons of Pope Pius X and assume the directorship of the Vatican ...
    • A Fifty-Foot Mercury Telescope 

      Rigge, William F., S.J. (1922)
      First Paragraph: | Some months ago the press brought the great news that a monster telescope, 50 feet in diameter, was being projected on an entirely novel and reliable principle, such that its construction would not only ...
    • The Frequency of Total Eclipses of the Sun at a Given Place 

      Rigge, William F., S.J. (1924)
      First Paragraph: | We may put it down as a fact, that whenever an eclipse of the Sun occurs at any place, the astronomer there is sure to be asked, especially by the representatives of the press: “Does an eclipse of the ...
    • Gaging a Horizontal Cylinder 

      Rigge, William F., S.J. (1916)
      First Paragraph: | The actual amount of liquid present at any time in a horizontal cylindrical tank may be gaged very rapidly, if we make use of a graphic process such as is furnished by the diagram in this article. As the ...
    • Harmonic Curves 

      Rigge, William F., S.J. (Creighton University. Omaha, Nebraska, 1926)
      Harmonic curves always captivate the eye by their wonderful beauty and their endless variety. They have that correct proportion in their parts which delights the artist, that simplicity of construction in their apparent ...