Oct. 20, 1 881] 



NATURE 



583 



line joining any two particles of air sliall always be parallel 

 to its original direction, an assumption which is manifestly 

 incorrect. If I rightly understand the description of Mr. 

 Wilson's integrator on p. 467, the trace given by it is 

 precisely that which has just been shown in the case of my o.vn 

 machine to be based on a fallacious assumption. But though 

 the trace may be useless, the summation of the movements of 

 the table above described gives results which are representative 

 of physical realities, being in fact the quadrantal components of 

 the wind-movement at the station during the period dealt with 

 by the machine. I trust that the preceding remarks w ill suffice 

 to ju-tify the statements contained in my last letter. Dr. von 

 Oettingen's remark, referred to in my concluding sentence, 

 related, not to his wind-component-integrator, but to the con- 

 tinual change of form in what may be called the physical 

 Lambert's line, and implied the consequent .idvitability of dis- 

 carding Lambert's method of treatment. 



Charles E. Burton 

 38, Barclay Road, Walham Green, S.W., October 14 



P.S, — On September 21 last I forwarded to Prof. Stokes a de- 

 scription, with dravi'ings, of tvi'o forms of wind-compontnt in- 

 tegrator, suitable either for attachment to a cup and vane- 

 anemometer, or for the reduction of existing anemograms of 

 the pattern adopted by the Meteorological Oflice ; and of simpler 

 mechanism than my earlier machine, or Dr. von Oettingen's. 



Calabar Bean as a Preservative 



As many find such a diflicully in ]ireserving entomological and 

 other natural histoi-y specimens it may not be uninteresting to 

 your renders to have a brief note on the use of Calabar Bean as 

 a preservative. About eight years ago, when AquilH Smith, 

 M.D., Professor of Materia Medica, Trinity College, Dublin, was 

 showing me through the museum that he has rendered so famous, 

 I vfas struck by the perfect manner in which the specimens were 

 preserved ; the little brown beetle that is generally such a pest in 

 similar collections being entirely absent. Pr. Smith told me 

 that he treated the specimens with tinclure of Calabar Bean, and 

 very kindly gave me a bottle of the tincture. I used the tincture 

 freely in my cabinet of Lepidoptera, and, although the collection 

 has been wofuUy neglected Mnce, it has remained quite free 

 from mites. Dr. Smith tells me that the tincture was prepared 

 by Mr. Squire of 277, Oxford Street, London, its strength being 

 one part of the bean to eight of (rectified?) spirit. I might 

 mention that Mr. Fetherstonhaugh used some of the tincture 

 which I gave him in his cabinet, and was delighted with its 

 action. A drop of the tincture is placed on the body of the 

 insect. I found it a good plan to d j this whiLt the insect was 

 on the drying board, as otherwise, in newly set insects, the 

 damping with spirit caused the wings to spring. 



E. MacDowel Cosgrave 



A Correction 



1 FIND that the term "glissette " is not used precisely in the 

 sense which I had supposed. A reference to Mr. Besant's 

 " Notes on Roulettes and Gli~settes" (which I had not before 

 me last week) shows that the envelopes of the moving lines, to 

 which the theorem in my last letter refers, would be properly 

 described as rouletlis. It is obvious, however, that gli-^scltes are 

 in general also rouIe:tes. George AL Minchi.m 



Royal Indian Engineering College. 



Effect of Green in Painted Windows 

 I NOTICED to-day a curious effect in the east windows of Old 

 Upton Church which may interest artists among your readers, 

 and of which I should be glad to see any explanation. The 

 pattern is in small regular pieces in which a strong red is pre- 

 valent, especially in the ribbon round the edge. Green is 

 perhaps the least represented in area. At all events, generally, 

 red largely prevail-; over green. The latter i-i not over brilliant. 

 At a distance of ten feet the general effect is red. At that 

 distance I see the pat'ern sharply, and green is not at all obtru- 

 sive. At the length of the church, say fifty feet off, I cannot 

 distinguish the pattern, and the whole window looks a thin 

 watery green haze ; the bright red margin is inappreciable. 

 Richmond, October 12 W. J. Herschel 



THE A UTUMN MEETING OF THE IRON AND 



STEEL INSTITUTE 

 A T the meeting of the above Institution, which has 

 -'*■ just taken place, several papers of scientific and 

 practical interest were read and discussed. They may be 

 broadly divided into two classes, viz. ist, those relating to 

 the production of iron and steel, from the ore, and the 

 qualities of the material when produced ; and 2nd, 

 the various applications to which steel has been put in 

 recent times. The latter class of papers, at the recent 

 meeting, dealt principally with the use of steel in the 

 manufacture of ordnance, small arms, projectiles, and 

 gun-carriages and the papers, some of whiah were of great, 

 interest, will be reserved for consideration in a separate 

 notice, .'\mongst the papers dealing with the manufac- 

 ture of steel we may notice specially a memoir by Herr 

 Paul Kupelweiser of Witkowitz, in Austria, on recent pro- 

 gress attained in the use of the basic process at the works 

 with which he is connected. This process, which has 

 been frequently referred to in Nature, seems— probably 

 on account of the quality of the ores met with — to have 

 been adapted more frequently in Continental steel works 

 than in our own country, for according to Herr Kupel- 

 weiser's summary, no less than thirty works in France, 

 Belgium, Germany, Austria, and Russia, have acquired 

 licences under the Thomas patents, the greater nuinber 

 of these being already at work ; while the remainder are 

 adapting their old plant, or erecting new works with the 

 view to its immediate introduction. The weak point of 

 the process hitherto has undoubtedly been the want of 

 durability in the refractory linings of the converters, and 

 on this point the author states that, in spite of numerous 

 trials with other materials, the works with which he is ac- 

 quainted still use the materials originally proposed by Mr. 

 Thomas, viz. either the basic bricks or the shrunk lime 

 and tar mixture. At Witkowitz, however, a new material 

 has been used containing a comparatively sinall per- 

 centage of silica, and the quality of the bricks manufac- 

 tured from this has been found to be materially improved. 

 Ground brick mixed with 5 to 10 per cent, of tar is also 

 used at many works for lining as well as for repairs. 

 Basic tu) &res have been tried in many places, but are not 

 commonly used ; but the author states that magnesia 

 obtained by precipitation from chloride of magnesia by 

 milk of lime appears, from experiments made on a small 

 scale, to be a promising material for making tuyeres. As 

 regards the quality of the steel he makes the following 

 remarkable statement :—" The basic process, as regards 

 the quality of its products, is not only completely equal 

 to the acid process, but even, in my opinion, superior to 

 the latter." As a specimen of the excellent q'lality of the 

 mild steel manufactured at Witkowitz ihe author exhi- 

 bited a locomotive boiler tube made of this material, 

 which had been expanded cold by it cans of a tube 

 expander froin 9 to 17 millimetres, on an original dia- 

 meter of 48 millimetres, equal to an extension of from 20 

 to 36 per cent, on the periphery of the material, without 

 even splitting at the line of weld. 



Another paper of great interest to foreign manufac- 

 turers was Prof. Ttmner's memoir " On the Use of Lignite 

 or Brown Coal in the Blast Furnace." It is well known 

 that the Austro-Hungarian Empire contains immense 

 deposits of this fuel, 'it would be difficult to over-esti- 

 mate the benefit which would accrue to the iron industry 

 of Austria if this abundant and inexpensive fuel could 

 be used successfully in the blast-furnace. .All the experi- 

 ments made in this direction till last year were of a more 

 or less isolated and unsatisfactory character. In June, 

 1880, however, the " Mining and Metallurgical Associa- 

 tion of Styria and Carinthia " appointed a committee to 

 investigate the subject afresh. This committee has not 

 yet reported, or indeed concluded its labours, but it is 

 satisfactory to learn that it is fully acknowledged that 

 there if no theoretical difficulty in the way of smelting 



