Sept. 22, 1882.] 



♦ KNO\VLEDGE ♦ 



271 



.^ci V^ AN ILLiLaiRATED "^ Jy> 



MAGi^ZlNEoFSQIfNCE , 



PLAINLt ^ORDED -EXACTlf DESCRIEED J 



LONDON: FRIDAY, SEPTEMBER 22, 1882. 



Contents op No. 47. 



1 Ird Clodd..'. 273 



^" Iltiutraled.) 



I 27-* 



EL- ■ ! _ 4 275 



Butterllies and Moths. ByW.J.H. 



CUrk 276 



Are Toads Poisonous ? 277 



Clouds in the Air. (lUuttraied.) 



Bv the Editor 278 



Compound Nest, {niustrated.) 279 



Carbonic Acid in the Air : 



Correspondence : — Singular Rain- 

 bow — Mechanical Paradox — Hot 

 and Cold Drinks — Skeleton Leaves 

 —Brain Troubles— A Luminous 

 Sea — "A Glass of Wine " — 

 Poisonous Lizard — Botanical Re- 

 pulsion and Attraction — Tarnished 



Daguerreotype, &c 2 



Ajlswers to Correspondents S 



^txtrnt anb art #05s(ip. 



Discovery of a Co.met. — A circular from Lord Craw- 

 ford's Observatory at Dunecht says : — " Monsieur Cruls 

 telegraphs from Rio Janeiro, by the Science Observer Code, 

 the discovery of a comet on September 11-718 M. T. (Riol) 

 in R. A. 9h. 48min ; Dec! - 2° 1'. M. Cruls says that it 

 is visible to the naked eye, and is probably the expected 

 Comet Pons of 1812." 



Mr. a. Aixslie, of the Common, Ealing, says the Times, 

 telegraphed to us yesterday : — "This morning, at 10. -1.5, I 

 found a magnificent comet west of the sun about G rain, 

 and about 1-3° south. It is approaching the sun rapidly, 

 and is, no doubt, the comet referred to in the Earl of 

 Crawford's Circular, No. .5-1." [For Mr. A. Ainslie, of the 

 Common, Ealing, read Mr. A. .Ainslie Common, Ealing. — 

 Ed.] 



The Use of Balloons in War. — The objection to the 

 use of balloons in war time always has been the possibility 

 of the enemy firing at and disabling them, to the certain 

 death of the unfortunate occupant Mr. A. Cooper Key 

 writes to a daily paper suggesting a plan by which this 

 risk could be obviated. He proposes that a small captive 

 balloon, from which four cameras fi.xed to a square frame 

 are suspended, should ascend to a given height — say half 

 or three-cjuarters of a mile ; the four lenses, previously 

 focussed, must be towards the earth, and closed with in- 

 stantaneous shutters, capable of being moved by galvanic 

 battery, the wires from which could bo carried by the 

 rope which tethers the balloon, and the frame in which 

 cameras are fixed should have facing plates at an angle of 

 45°, and be prominently painted in diilbrent coloured 

 symbols which could be clearly read oft" from the field of 

 observation. The officer in charge should be provided with 

 a field-glass, mariner's compass, and a sheet of ptiper with 

 symbols painted to correspond with those on tlie camera 

 frame, so as to note the position of balloon the instant 

 contact is made by means of the battery. Thus, when the 

 balloon is brought to earth, the exact situation in which 

 the pliotograph was taken can be ascertained. 



Edison v. Maxim. — A suit has been brought by the 

 Edison Company against H. E. Maxim for infringing 

 Edison's incandescent lamp patents. The trial will probably 

 take place in Paris in November next. — Electrician. 



The Enyineer says : — The unsanitary condition of cer- 

 tain towns in the United States has drawn attention to 

 the fact that wooden houses, and especially wooden founda- 

 tions, are liable after a certain time to cause malarial 

 symptoms. So many malarious attacks have been expe- 

 rienced of late years in San Francisco that the medical 

 men began to suspect the buildings, especially as the 

 structures themselves, which are nearly all built on wooden 

 foundations, began to show disturbances, cracks appearing 

 in the walls, and the floors settling. Scientific investigation 

 into the causes of these troubles points to the fact that the 

 wood used in the foundations becomes decayed by contact 

 with the sand, which destroys its fibre and leaves it porous 

 and brittle. The next stage in the process is the formation 

 of a fungus growth from the edge of the wood, composed of 

 infinitesimal insect life, which burrows the remaining 

 wood until its vitality is gone, and the insect itself dies. 

 Physicians attribute many of the unpleasant smells and 

 the bad health that hang about the inhabitants of these 

 dwellings to this malarial condition, which to a great 

 extent disappears as soon as proper foundations are sub- 

 stituted for those of wood. There are doubtless many old 

 houses in this country which, without being actually 

 dangerous to health, have constantly hanging about them 

 a damp odour of decay, giving rise to malaise, and it is 

 most probable that the woodwork will in many cases be 

 found to be permeated by insect life. 



Ancient Works in Florida. — The Traiers Jlerald de- 

 scribes the finding of an ancient work in digging a canal 

 between Lakes Eustis and Dora, to open up the more' 

 southern lakes of the great lake region of Florida. The 

 first excavations revealed the existence of a clearly-defined 

 wall lying in a line toward the south-west, from where it 

 was first struck. The wall was composed of a dark brown 

 sandstone, very much crumbled in places, but more distinct, 

 more clearly defined, and the stone more solid, as the digging 

 increased in depth. The wall was evidently the eastern 

 side oC an ancient home or fortification, as the slope of the 

 outer wall was to the west. About eight feet from the 

 slope of the eastern wall a mound of sand was struck, em- 

 betlded in the muck formation above and around it This 

 sand mound was dug into only a few inches, as the depth of 

 the water demanded but a slight increased depth of the 

 channel at that point ; but enough was discovered to 

 warrant the belief that here on the north-western shore of 

 Lake Dora is submerged a city or town or fortification 

 older by centuries than anything yet discovered in this 

 portion of Florida. Small, curiously shaped blocks of sand- 

 stone, some of them showing traces of fire, pieces of pottery, 

 and utensils made of a mottled flint were thrown out by 

 the men while working waist deep in water. One spear- 

 head of mottled flint, five and a-lialf inches long by one 

 and a-quarter inches wide, nicely finished, was taken from 

 the top of the sand mound, and about four feet below the 

 water level of the lake. 



The Telephone in the Divin(vBell.— The Neiocastle 

 Chi-onic/e says the telephone has been applied as a means 

 of signalling between the workmen in the River Wear 

 Commissioners' diving-bell and the workmen in charge of 

 tlie crane and air pump for governing the bell, in the craft 



