| RefNo | MS/603/8/30 |
| Previous numbers | 1369 |
| Level | Item |
| Title | Letter from H M [Hector Munro] Macdonald, 52 College Bounds, Aberdeen, to [Joseph] Larmor |
| Creator | Macdonald; Hector Munro (1865-1935); British mathematician |
| Recipient | Larmor; Sir Joseph (1857-1942); Irish theoretical physicist |
| Date | 22 October 1913 |
| Description | Macdonald asks if there is any accurate observation of the intensity of sound from a foghorn and different distances. He thinks he has been told that there was at least one belt of silence beyond which the foghorn could be heard again. His analysis suggests that this might happen, but he has not reduced it to numbers yet, and he would like to have data to compare with theoretical results. He also has 'the distance to which the creeping effect at the edge of the shadow extends'. He gives details for a wavelength of 2 1/2 miles and where the shadow begins to act effectively. After dropping off suddenly, it obeys the law he gave in 1909. He notes what he is really working on in transmiters, which he hopes to write up over Christmas. He thinks Larmor will have seen a paper in the Annalen der Physik 'by an author with an unpronoucable name' proving [Henri] Poincaré wrong in his Palermo Transactions of 1910. The author has not hit the weak spot in Poincaré and has not worked out the proper answer. Macdonald is now immersed in lectures; Charles Niven is back at work and seemingly fit. |
| Extent | 4p. |
| Format | Manuscript |
| PhysicalDescription | Ink on paper |
| AccessStatus | Open |
Fellows associated with this archive
| Code | PersonName | Dates |
| NA1351 | Macdonald; Hector Munro (1865 - 1935) | 1865 - 1935 |