scholarly journals I. An experimental determination of the velocity of sound

1872 ◽  
Vol 162 ◽  
pp. 1-6
Keyword(s):  
Experimental Determination ◽  
Velocity Of Sound ◽  
Galvanic Current ◽  
Dry Air ◽  
Cape Of Good Hope ◽  
Point Of Interest ◽  
Royal Observatory ◽  
Port Elizabeth ◽  
Mean Time

A galvanic current passes from the batteries at the Royal Observatory, Cape of Good Hope, at 1 o’clock, Cape mean time. This current discharges a gun at the Castle, and through relays drops a time-ball at Port Elizabeth. It appeared to me that a valuable determination of the velocity of sound might be obtained by measuring upon the chronograph of the Observatory the time between the sound reaching some point near the gun and that of its arrival at the Observatory. I thought also that it would be a point of interest to check, within the limits of our changes of temperature, the variations in the velocity of sound as dependent upon temperature, and to obtain some test of the applicability of the coefficient of expansion of dry air, as determined in cabinet experiments, to the mixture of air and water which would be the medium of the propagation of sound in our experiments.

III. An experimental determination of the velocity of sound

1872 ◽  
Vol 20 (130-138) ◽  
pp. 34-35
Keyword(s):  
Experimental Determination ◽  
Cape Town ◽  
The Other ◽  
Velocity Of Sound ◽  
Successful Operation ◽  
Single Wire ◽  
Galvanic Current ◽  
Royal Observatory ◽  
Port Elizabeth

A galvanic current passes from the batteries at the Royal Observatory, Cape Town, at 1 o’clock, and discharges a gun at the Castle, and through relays drops a time-ball at Port Elizabeth. It appeared to the author that a valuable determination of the velocity of sound might be obtained by measuring upon the chronograph of the Observatory the interval between the time of the sound reaching some point near the gun and that of its arrival at the Observatory. As there is only a single wire between the Observatory and Cape Town, some little difficulty was experienced in making the necessary arrangements, without any interference with the 1 o’clock current to Port Elizabeth; but this difficulty was overcome by a plan which the author describes, and which was brought into successful operation on Feb. 27, 1871. The experiments could not have been carried out, on account of the encroachment they would have made on the time of the Observatory staff, had it not been for the assistance of J. Den, Esq., the acting manager of the Cape Telegraph Company, to whom the author is indebted for the preparation of a good earth-connexion near the gun, for permission to Mr. Kirby, a gentleman attached to the telegraph office, to assist in the experiments, and for a general superintendence of the arrangements at Cape Town. The observed times of hearing the sound were recorded on the chronograph by two observers, situated one (Mr. Kirby) at a distance of 641 feet from the gun, the other (Mr. Mann) at the Observatory, at a distance of 15,449 feet from the gun. The former distance was sufficient to allow the connexion of the main wire to be broken at the telegraph office after the gun had been fired, but before the sound reached the first observer.

Harold Spencer Jones, 1890-1960

1961 ◽  
Vol 7 ◽  
pp. 136-145
Keyword(s):  
Natural Sciences ◽  
Magnitude Scale ◽  
Isaac Newton ◽  
The Third ◽  
Cape Of Good Hope ◽  
The North ◽  
Royal Observatory ◽  
North Polar

Harold Spencer Jones was the third child, and eldest son, of Henry Charles Jones, an accountant, and Sarah Ryland, who had been a schoolmistress. He was born in Kensington on 29 March 1890 and exhibited as a child a remarkable interest in mathematics. He was encouraged in his mathematical interests by his parents, and went to Latymer Upper School, from which he won a scholarship to Jesus College, Cambridge. He took a First Class in Part I of the Mathematical Tripos in 1909, and was a Wrangler in Part II of the Tripos in 1911. He then read Part II of the Natural Sciences Tripos, in Physics, and again secured a First. He was second Smith’s Prizeman in 1913 and Isaac Newton Student in 1912. In 1913 he was elected to a Fellowship in Jesus College. In 1913 he was appointed Chief Assistant at the Royal Observatory, which was then at Greenwich, where he remained for ten years, with some interruption occasioned by the 1914-1918 war. During Spencer Jones’s first period at Greenwich he went to Russia with C. R. Davidson to observe the eclipse of 1914. He wrote several papers on a subject which remained one of great interest to him, namely the variation of latitude, as observed by the Cookson floating telescope. He also made a determination of the photographic magnitude scale of the North Polar Sequence. In the midst of these activities, he was appointed to the office of H.M. Astronomer at the Cape of Good Hope, taking up office in 1923. He was, of course, a young man to be appointed to such a position, in which he was director of a large observatory.

scholarly journals VII. Outlines of experiments and inquiries respecting sound and light. By Thomas Young, M. D. F. R. S. In a letter to Edward Whitaker Gray, M. D. Sec. R. S

1800 ◽  
Vol 90 ◽  
pp. 106-150 ◽  
Keyword(s):  
Royal Society ◽  
Velocity Of Sound ◽  
Human Voice ◽  
The Subject ◽  
The Mean ◽  
Elastic Fluids ◽  
Musical Sounds ◽  
Mean Time

Dear Sir, It has long been my intention to lay before the Royal Society a few observations on the subject of sound; and I have endea­voured to collect as much information, and to make as many experiments, connected with this inquiry, as circumstances enabled me to do; but, the further I have proceeded, the more widely the prospect of what lay before me has been extended; and, as I find that the investigation, in all its magnitude, will occupy the leisure hours of some years, or perhaps of a life, I am determined, in the mean time, lest any unforeseen circumstances should prevent my continuing the pursuit, to submit to the Society some conclusions which I have already formed from the results of various experiments. Their subjects are, I. The measurement of the quantity of air discharged through an aperture. II. The determination of the direction and velocity of a stream of air proceeding from an orifice. III. Ocular evidence of the nature of sound. IV. The velocity of sound. V. Sonorous cavities. VI. The degree of divergence of sound. VII. The decay of sound. VIII. The harmonic sounds of pipes. IX. The vibrations of different elastic fluids. X. The analogy between light and sound. XI. The coalescence of musical sounds. XII. The frequency of vibrations constituting a given note. XIII. The vibrations of chords. XIV. The vibrations of rods and plates. XV. The human voice. XVI. The temperament of musical intervals.

Time and Latitude in South Africa

1972 ◽  
Vol 1 ◽  
pp. 27-38
Author(s):  
J. Hers
Keyword(s):  
South Africa ◽  
Cape Town ◽  
Astronomical Observations ◽  
Royal Observatory ◽  
The Republic ◽  
Astronomical Determination ◽  
Limited Accuracy ◽  
Better Than

In South Africa the modern outlook towards time may be said to have started in 1948. Both the two major observatories, The Royal Observatory in Cape Town and the Union Observatory (now known as the Republic Observatory) in Johannesburg had, of course, been involved in the astronomical determination of time almost from their inception, and the Johannesburg Observatory has been responsible for the official time of South Africa since 1908. However the pendulum clocks then in use could not be relied on to provide an accuracy better than about 1/10 second, which was of the same order as that of the astronomical observations. It is doubtful if much use was made of even this limited accuracy outside the two observatories, and although there may – occasionally have been a demand for more accurate time, it was certainly not voiced.

Experimental determination of a state equation for dissipative granular gases

1999 ◽  
Vol 96 (6) ◽  
pp. 1111-1116 ◽  
Author(s):  
E. Falcon ◽  
S. Fauve ◽  
C. Laroche
Keyword(s):  
Experimental Determination ◽  
State Equation ◽  
Granular Gases
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