POPULAR MISCELLANY. 



139 



tion of weather conditions and phenomena 

 in other parts of the kingdom indicates that 

 there were other observers in England who 

 corresponded with Merle. A comet was 

 seen in the second week of September, 1343, 

 appearing about sunset. Our author called 

 it " ardens draco,' 1 '' or burning dragon, but 

 did not seem terrified by it. He merely re- 

 marked that it was a sign of dry weather. 

 In the same year, on the 28th of March, is 

 entered a notice of an earthquake so violent 

 that the stones of the chimneys in certain 

 parts of Lindsey were thrown down. The 

 motion lasted while one might say the an- 

 gelic salutation, which was about half as long 

 then as it is now. The mention of stones 

 falling in the stone chimneys " lapides 

 in caminis lapideis " is interesting, as it 

 proves the fallacy of the belief that chimneys 

 are a late invention, and that the English 

 of those times were so barbarous that the 

 smoke was got rid of by means of a hole in 

 the roof. The recovery of the journal is due 

 to a mention of it by Dr. Plot, of the Royal 

 Society, in 1685, as being in the Bodleian 

 Library. It was looked for and found. 



Drops of Fog. Advantage was taken by 

 Mr. John Aitken, during a visit to the Righi, 

 of the opportunities that were afforded there 

 for investigating the water particles in 

 clouds. With an instrument the author has 

 invented those particles were distinctly seen 

 showering down, and the number falling on 

 the micrometer was easily counted. The 

 number was observed to vary greatly from 

 time to time. The greatest rate actually 

 counted was sixty drops per square milli- 

 metre in thirty seconds, but for a few sec- 

 onds the rate was much quicker. The maxi- 

 mum rate named gives twelve thousand drops 

 per square centimetre per minute, or sev- 

 enty-seven thousand four hundred drops per 

 square inch per minute. The drops are so 

 extremely small that they rapidly evaporate, 

 more than two or three being seldom visi- 

 ble at the same time on one square of the 

 micrometer. The denser the cloud the quick- 

 er was the rate of fall, and as the cloud 

 thinned away the drops fell at longer inter- 

 vals, and they diminished in size at the 

 same time. It was frequently observed 

 when the mountain-top was in clouds, par- 

 ticularly if they were not very dense over- 



head, that the surfaces of all exposed ob- 

 jects were dry not only the stones on the 

 ground, which might have received heat from 

 the earth, but also wooden seats, posts, etc. 

 and if wetted they soon dried. And while 

 everything was dry, the fog-counter showed 

 that fine rain-drops were falling in immense 

 numbers, and the air, on testing, was found 

 to be saturated. A few observations were 

 therefore made to explain the apparent con- 

 tradiction of surfaces remaining dry while 

 exposed to a continued shower of fine rain 

 and surrounded by saturated air. The ex- 

 planation was found to be, simply, radiant 

 heat. A considerable amount of heat, as 

 also of light, was found to penetrate the 

 clouds, notwithstanding their density. This 

 radiant heat is absorbed by all exposed sur- 

 faces and heats them, while they in turn 

 heat the air in contact with them, and the 

 fine drops of water are either evaporated in 

 this hot layer of air or after they come in 

 contact with the heated surfaces. Other 

 observations made on Mount Pilatus pointed 

 to the same conclusion. All large objects, 

 such as seats, posts, etc., were dry in cloud 

 when there was any radiation ; while small 

 objects, such as pins, fine threads, etc., were 

 covered with beads of water. The large sur- 

 faces being more heated by radiation than 

 small ones, when surrounded by air, these 

 surfaces evaporate the drops falling on 

 them, while the small ones, being kept cool 

 by the passing air, are unable to keep them- 

 selves free. The observations made with 

 the fog-counter point to the conclusion that 

 the density or thickness of a cloud depends 

 more on the number of water particles than 

 on the number of dust particles in it. 



Mortality and Morbidity by Professions. 



M. Jacques Bertillon recently communi- 

 cated to the French Society of Public Medi- 

 cine a table of mortality by professions, 

 compiled from official documents of the city 

 of Paris from 1885 to 1889. This is the 

 first table of the kind that has been made 

 in France. Other tables have been made in 

 England by Mr. William Farr and by Mr. 

 Ogle, compiled from the returns of census 

 years, and in Switzerland by M. Kummer 

 for the years 1879 to 1882. On a comparison 

 of the results of these four tables, made with 

 special reference to the relative number for 



