scholarly journals Günther Oestmann, The Astronomical Clock of Strasbourg Cathedral: Function and Significance. Trans. Bruce W. Irwin

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Carole Taylor
Keyword(s):  
Astronomical Clock

Günther Oestmann, The Astronomical Clock of Strasbourg Cathedral: Function and Significance. Trans. Bruce W. Irwin Leiden and Boston: Brill, 2020. Hardback xvi, 348 pp. ISBN: 978-90-04-42346-6. $179.00.

scholarly journals XVII. Description of an escapement for an astronomical clock, invented by the late Captain Henry Kater, F.R.S. &c., drawn up from his own memorandums by his son Edward Kater, Esq. Communicated by Sir J. F. W. Herschel, Bart., K. H. V. P. R. S. &c

1840 ◽  
Vol 130 ◽  
pp. 335-340
Keyword(s):  
Royal Society ◽  
Astronomical Clock ◽  
The Many

In venturing to offer to the attention of the Royal Society the following description of an escapement for an astronomical clock, I beg to premise that I restrict myself almost entirely to the collecting and arranging of my father’s own notes respecting it, written at intervals during the many years he was engaged upon it. His last improvement was made very shortly before his death, but from increasing ill health he was unable to pursue the requisite observations for verifying the accuracy of the present plan. Owing to the numerous memorandums left by my father on this subject, I am fortunately able to give the description of the escapement nearly in his own words, with but little addition beyond some drawings which I have made to elucidate the explanations.

Circadian organization of chitin in some insect skeletons

1965 ◽  
Vol s3-106 (76) ◽  
pp. 315-325
Author(s):  
A. C. NEVILLE
Keyword(s):  
Circadian Clock ◽  
General Feature ◽  
Periplaneta Americana ◽  
Constant Darkness ◽  
Actual Rate ◽  
Rate Of Increase ◽  
Parallel Fibres ◽  
Astronomical Clock ◽  
Circadian Organization ◽  
Water Bugs

A circadian clock is shown to be involved in the control of macromolecular orientation of chitin by cells secreting and organizing insect endocuticle. Daily organization of locust endocuticle into alternating lamellate and non-lamellate layers persists in constant temperature (36° C) and constant darkness for at least 2 weeks; the freerunning period is then about 23 h, so that after a number of days the circadian clock is 180° out of phase with the astronomical clock, with which it is normally phased. The rhythm is almost independent of temperature, with a Q10 of 1.04, as contrasted with a Q10 of 2.0 for the actual rate of increase of endocuticular thickness. Locust epidermal cells differ in response to specific imposed environmental conditions according to their location in the integument. In some cells, constant low temperature uncouples chitin lamellogenesis from the circadian clock, provided that illumination (light or dark) is constant also: the result is continuously lamellate endocuticle. In other cells constant light acts as an uncoupling factor, provided that temperature (high or low) is constant also: the result in this case is continuously non-lamellate endocuticle. The circadian rhythm of chitin lamellogenesis persists in a cave cricket (Dolichopoda linderi). A similar circadian lamellogenesis rhythm occurs in the endocuticle of nymphs and adults of the cockroach Periplaneta americana. A crossed-fibre multiple-ply endocuticle in the legs and wings of giant toe-biter water bugs (Belosto-matidae) also displays circadian organization, the chitin macromolecules in any one layer lying in parallel fibres, at an angle of approximately 6o° to those in the next layer. It is suggested that daily organization of the skeleton may be a general feature of arthropods. Examples include the phenomena of timing of chitin lamellogenesis; chitin crossed-fibrillar organization; degree of fluorescence of the rubber-like protein resilin; and mineralization of crayfish gastroliths.

scholarly journals VI. On a new astronomical clock, and a pendulum governor for uniform motion

1869 ◽  
Vol 17 ◽  
pp. 468-470
Keyword(s):  
Uniform Motion ◽  
Geometrical Transformation ◽  
Astronomical Clock ◽  
The Dead ◽  
Better Than

It seems strange that the dead-beat escapement should still hold its place in the astronomical clock, when its geometrical transformation, the cylinder escapement of the same inventor, Graham, only survives in Geneva watches of the cheaper class. For better portable time-keepers, it has been altered (through the rack-and-pinion movement) into the detached lever, which has proved much more accurate. If it is possible to make astronomical clocks go better than at present by merely giving them a better escapement, it is quite certain that one on the same principle as the detached lever, or as the ship-chronometer escapement, would improve their time-keeping. But the inaccuracies hitherto tolerated in astronomical clocks may be due more to the faultiness of the mercury compensation pendulum, and of the mode in which it is hung, and of the instability of the supporting clock-case or framework, than to imperfection of the escapement and the greatness of the arc of vibration which it requires ; therefore it would be wrong to expect confidently much improvement in the time-keeping merely from improvement of the escapement. I have therefore endeavoured to improve both the compensation for change of temperature in the pendulum, and the mode of its support, in a clock which I have recently made with an escapement on a new principle, in which the simplicity of the dead-beat escapement of Graham is retained, while its great defect, the stopping of the whole train of wheels by pressure of a tooth upon a surface moving with the pendulum, is remedied.

scholarly journals Very Weak Signals (VWS) detected by stacking method according to different astronomical periodicities (HiCum)

2007 ◽  
Vol 7 (6) ◽  
pp. 651-656 ◽  
Author(s):  
M. van Ruymbeke ◽  
P. Zhu ◽  
N. Cadicheanu ◽  
S. Naslin
Keyword(s):  
Weak Signals ◽  
Sliding Windows ◽  
Volcanic Events ◽  
Astronomical Clock ◽  
Phase Variations

Abstract. A stacking method to detect very weak signals is introduced in this paper. This method is to stack observed data in different well known periodicities according to the astronomical clock since majority geophysical observations are time based. We validated this method by applying it in four different cases. Interactions behind the observed parameters become obviously after it is stacked in two diurnal and semidiurnal tidal periodical waves. Amplitude and phase variations will be also measurable when a sliding windows stacking is used. This could be an important reference to find precursors before some earthquakes and volcanic events, corresponding to attenuations of medium patterns.

LI. An account of the going of an astronomical clock

1771 ◽  
Vol 61 ◽  
pp. 559-566
Keyword(s):  
The Public ◽  
Astronomical Clock

Having heard if often lamented, that very few registers of the going of clocks have been communicated to the public; I take the liberty to lay before the Society such observations as I have made to ascertain mine; and shall be happy if my amusements can in any way be of the least service to any one.

The Wheel of Fortune

2020 ◽  
pp. 35-44
Author(s):  
Nicholas Mee
Keyword(s):  
Early Development ◽  
Southern England ◽  
Astronomical Clock

Chapter 4 looks at the early development of the mechanical clock. The fully mechanical clock may have been invented in southern England around 1280, possibly at Dunstable Priory in Bedfordshire. One line of evidence derives from a commentary on Sacrobosco’s De Sphaera Mundi by Robertus Anglicus, written in 1271. The chapter discusses subsequent developments and, in particular, the life and work of Richard of Wallingford, who rose from humble beginnings to become Abbot of St Albans. In 1327 he wrote Tractatus Horologii Astronomici (Treatise on the Astronomical Clock). The manuscript was rediscovered by John North in 1965, and it has been used to reconstruct Wallingford’s clock, which is now on display in St Albans Cathedral.

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