2 8o 



NATURE 



[May 15, 1913 



Red Book No. 173 of the British Fire Prevention 

 Committee contains an account, with photographs, 

 of tests on reinforced concrete doors. These doors 

 were constructed to the designs of Commandant 

 Welsch, ex-chief officer of the Ghent Fire Brigade. 

 No. 1 door had a T iron rim and expanded metal and 

 flat-iron reinforcement filled in with concrete; this 

 door was hung on runners and made to slide, and 

 was fixed on the outside of an opening. No. 2 door 

 was similar to No. 1 door, but fixed on the inside 

 of an opening. In No. 3 test two doors as described 

 above were used, one on the inside and one on the 

 outside of an opening. In No. 3 test, the doors were 

 subjected to the action of a fire of 150 minutes' dura- 

 tion at temperatures gradually increasing to about 

 2000 F., followed by the application of water for two 

 minutes on the fire side. In thirty-two minutes the 

 outer face of the outer door was too hot to bear the 

 hand, and in 140 minutes the lower half of the door 

 had bulged outwards. In seventeen minutes cracks 

 appeared all over the fire side of the inner door and 

 continued to increase ; in 107 minutes this door came 

 away from the runner at one top corner ; in 150 

 minutes the door fell forwards into the interior of 

 the hut. On water being applied, the inner face of 

 the outer door was eroded where struck by the jet. 

 The tests afford some very useful lessons and give 

 information which should lead to the design of an 

 efficient fireproof reinforced concrete door. 



The report of the council and the proceedings of 

 the Hampstead Scientific Society for the year 1912 

 show that the work of the society, which was founded 

 in 1899, not only expanded greatly during the year, 

 but increased in value. It is hoped that during the 

 present month the work " Hampstead Heath : its 

 Geology and Natural History," prepared by members 

 of the society, will be published. The Mayor and 

 Borough Council of Hampstead have invited the 

 South-Eastern Union of Scientific Societies to hold its 

 annual congress at Hampstead this summer, and the 

 meetings will be held from June 4 to 7. Thirty-two 

 meetings were held during the year, besides six sum- 

 mer outdoor meetings and a course of four lectures 

 to juveniles during the Christmas holidays. Among 

 the list of lecturers during the year we notice the 

 names of the president of the society, Prof. W. M. 

 Flinders Petrie, and of Profs. A. Fowler and A. W. 

 Porter. The report records a deficit on the general 

 working of the society, due to the heavy expenditure 

 involved in the maintenance of the meteorological 

 station, which has now three years of unbroken 

 meteorological records to its credit. 



Among the most recent additions to the admirable 

 series of "The People's Books," which Messrs. T. C. 

 and E. C. Jack are publishing at 6d. net each, are 

 three volumes dealing with subjects of science and 

 technology. Dr. P. Phillips writes on the "Science 

 of Light," and intends his book to be a companion^ 

 to that on " Radiation," already published in the 

 series. In between eighty and ninety small pages he 

 deals with the propagation, reflection, refraction, dis- 

 persion, interference, and polarisation of light, and 

 also explains diffraction and the electromagnetic nature 

 NO. 2272, VOL. 91] 



of light waves. The treatment is necessarily slight, 

 but the volume will prove useful even to students of 

 physics, because of the outline history of the science 

 which it contains. In a volume on " British Birds," 

 Mr. F. B. Kirkman gives descriptions of 187 of the 

 commoner species and their nests and eggs. Mr. 

 A. W. Seaby has provided 1 1 1 illustrations, which, 

 though small, give a good idea of the birds described. 



I The third book is on "Gardening," and is by Mr. 



[ A. C. Bartlett, who has confined his attention to 

 descriptions of the chief gardening operations and the 

 propagation of plants by cuttings, grafting, budding, 

 and other methods. 



OUR ASTRONOMICAL COLUMN. 

 A New Faint Comet (19130).— A Kiel telegram of 

 date May 7 reports the discovery of a comet of mag- 

 nitude 95 on May 6, at i5h. 5m. mean time, Nice, by 

 M. Schaumasse, of the Nice Observatory. Its position 

 when discovered was given as R.A. 2oh. 54m. 44s., 

 and declination +9 52', and it was moving in a 

 north-easterly direction. 



A Kiel circular of May 10 gives the following 

 elements and ephemeris, computed bv Kiess and 

 Nicholson : — 



T = May 17-91 G.M.T. 



»= 57" 28' 



</ = 3i7° o' 



/ = 26 26' 



q = 1 440 



a 6 



h. m. s. 

 May 15 ... 20 16 12 ... + 19 o 

 „ 19 ... 19 48 37 ... +24 13 

 ,. 23 ■•• 19 II 22 ... +30 7 

 The comet rises this evening about 9.20, and should 

 be capable of being seen with telescopes of moderate 

 power in the early morning hours. 



The Physical Appearance of Mars. — It is well 

 known that observers of the planet Mars are divided 

 into two schools, one believing that the so-called 

 canals are really long, continuous, and narrow streaks, 

 the other looking upon them as the summation of a 

 complexity of detail revealing irregular streaks and 

 presenting; frequent interruptions and condensations. 

 In the current number of Knowledge, Mr. Antoniadi, 

 a strong advocate of the latter view, communicates 

 an interesting article on the subject of these Martian 

 markings, and puts forward his explanation of the 

 divergency of ideas of observers on their appearance. 

 Large versus small aperture is his main reason; thus 

 he writes : — " The student who passes many consecu- 

 tive hours in the study of Mars with medium-sized 

 instruments is liable to catch rare glimpses of straight 

 lines, single or double, generally lasting about one- 

 quarter of a second. Here we have a vindication of 

 Schiaparelli's discoveries. But their deceitful char- 

 acter will obtrude itself on the observer using a large 

 telescope, when, in the place of lines, he will behold 

 steadily either a winding, knotted, irregular band, 

 or the jagged edge of a half-tone, or some other com- 

 plex detail." ihe article is illustrated by a fine set 

 of drawings of the planet made in 191 1, "the observa- 

 tions being made with the 33-in. refractor of the 

 Meudon Observatory. 



The National Observatory of Athens. — Vol. vi. 

 of the Annales de VObservatoire National d'Athenes 

 contains a series of valuable contributions published 

 under the direction of Prof. Demetrius Eginitis, the 

 director of the observatory. It is only possible here 

 to state the titles of the memoirs and sets of observa- 



