PHILOSOPHICAL INSTITUTE.

Globe, Volume II, Issue 106, 2 October 1874, Page 2

PHILOSOPHICAL INSTITUTE.

The ordinary meeting of the Philosophical Institute of Canterbury was held on Thursday, at the Public Library. Present—Dr Haast (President), Drs Powell, Buller, and Coward, His Honor the Judge, Revs J. W. Stack, C. Fraser, Professor Bickerton, Messrs Condell, Fereday, Inglis, G. W. Hall, C. M. Wakefield, A. F. N. Blakiston. The minutes of the previous meeting were read and confirmed, A ballot was taken for the election of Mr Robert Parker as a member of the institute, and that gentleman was duly elected. The President expressed the pleasure he felt at welcoming Dr Buller once more amongst them.

Professor Bickerton then read the following paper on a new thermometer for lecture use : , , “ On a new thermometer for lecture purposes. —A thermometer of simple construction that may be seen by a large number of persons at once, is a piece of apparatus that would be very useful to the lecturer on heat, &c. “It would be of especial value in schools, &c., where but little time can be spent in preparing experiments. “A thermoelectric pile and galvanometer is a most valuable piece of apparatus. But there are many cases to which it does not apply well, nor is it well seen in a flat room, in which most elementary teaching is carried on. It is also expensive, and requires some skill to use satisfactorily. “ These considerations, and the necessity I have often felt for such an instrument, induced me to design the thermometer described below. ' “ The thermometer depends upon the different co-efficients of expansion of metals, and is constructed as follows :—About a dozen pairs of thin strips of zinc and steel, about four inches long, are rivetted at their alternate ends ; the two outside strips are continued on beyond one end of the bundle so formed. Each of these two pieces have a steel pin soldered across their ends ; these two pins work in holes in the end of a long index finger, which at the mean temperature of the range of the thermometer is in a straight line with the bundle of metal strips. “Any increase of temperature causes each of the zinc strips to expand more than the steel, and the sura of their difference is at once transmitted to the pins, one of which is thus thrust beyond the other, and causes the index to move on one side. When the temperature is lowered the index moves to the opposite side. “ The bundle of strips is filed up into a cylinder and placed in a copper tube, the bottom of which is closed. At the top of the tube is fixed a fanshaped piece of metal, on which is marked the scale of temperature. The index moves backwards and forwards in front of this scale.

“ The accompanying sketch shows the construction of the thermometer. “ When the thermometer is used before a large audience, the size of the scale may be increased by fixing to the back of the permanent scale a quadrant of black paper, having white figures on its circumference. The metal index being also increased in siz - ; by a long strip of white paper being pasted on it. With these additions the movement of the index produced by an alteration of a few degrees of heat may clearly be seen by an audience of any number. “ I have used the thermometer to illustrate the following facts ; “ 1. By its construction, it offers a good means of showing the difference of expansion of different metals. “2. The constant temperature of fusion and boiling. Thus the thermometer is placed n ice at moves up to 0 0.; it then remains still until all the ice is melted. It then goes on moving up to 100 0. “ 3. A pair shows well the difference rate of cooling of water in polished and blackened tin cubes. ‘‘4. The cold produced by the fusion of solids in the ordinary freezing mixtures. “5. The cold produced by evaporation. Of course a pair would show the difference of a wet and dry bulb thermometer. “ It might also be used to show the heat developed by friction, by placing in a ho’e in a block of wood made to revolve rapidly. “ It would also do well to show the constant boiling points of the different compounds in a substance subjected to fractional distillation, and for many other experiments. “ Mr Ward, of the School of Mines, has suggested it would be useful for fractional distillation at high temperatures, for which the mercurial thermometer is not available. “ I have had a thermometer made with brass instead of:, zinc,. for the purpose of making experiments extending over some time, to see if the instrument is reliable for purposes of observation of comparatively high temperatures. “ When the thermometer is required to be sensitive to a very small alteration of temperature I use two such bundles side by side, these two bundles are connected together by a diagonal pie?e of steel froth the top of one bundle to the bottom of the other. The two pieces supporting the pins are brought up together, one from each of the other ends of the bundles of strips. “ I may mention to any one wanting such thermometers, that Mr Ludd, London, and Mr Noble, Christchurch, have both made them, and are consequently conversant with their construction. “Notes on an alleged new species of tern, Sterna alia, (Potts). By Walter L. Buller, D. 5.., F.L.S.Mr Potts* in his notes on the birds of New Zealand, read before the Philosophical Institute of Canterbury, in December last (Trans. N. Z. 1., vol. VI., pp. 139-153), takes exception in the following terms to my treatment of his supposed new tern, Sterna alia ; “ The white tern seen by the writer on the Ashburton, and described by him in Trans. N. Z. Instit., vol. 111., is quietly placed by Dr Buller with S. nereis, to which he gives the name of the little white tern. This fine white tern was seen on the Waitangi River by the Hon G. Buckley and others. Last month (November 20th), a pair were seen flying up and down the course of that great river.

“On a careful reperusal of Mr Potts’ published notes, I acknowledge that I was wrong in referring'his bird to Sterna nereis ; but until a specimen has been actually obtained and examined, it is impossible to admit it into onr list as a recognised species. Mr Potts, in his original notice (1. c., p 107), merely described the bird as it appeared to him on the wing. He stated that the whole plumage was white, and that ‘ the bill appeared to be light colored,’ adding that these ‘ observations were made chiefly during its rapid movements.’ He gave no hint whatever of its size, although be now refers to it as a ‘fine white tern,’ as compared with the little white tern (S. nereis] ). “ On such a description as this, I fear that Mr Potts’ claim to the discovery of a new species would scarcely be admitted by ornithologists at home ; and, even if it were, the name of Sterna alba has been preoccupied by Gmelio. The bird may turn out, as_ Mr Potts himself suggests, to be identical with a species recorded from Norfolk Island. But if, on further acquaintance, it should prove to be jnew, I think we cannot do better than associate Mr Potts’ own name with it in lieu of the one he has proposed,”

Professor Bickerton then read the following paper:—

"A modification of the electric lamp, for projecting the spectra of different metals on the screen. To exhibit on the screen the spectrum of several raeta’s quickly one after another, by means of the electric light, is a matter of some difficulty when using the ordinary lamp. “A special piece of apparatus for this purpose is described by Mr Lockyer in his book, in which a circle of the ordinary gas carbon cups are used. I have made the following modifications of the ordinary lamp, which is very successful. “ The lower carbon is taken out, and into the holder is placed a stout cylinder of brass, with a pin turned on the top, on this pin is a plate of gas carbon, Sin diameter and jin thick, with a hole in the centre, through which passes the brass pin. The carbon disc is thus free to rotate. Around the top of the disc nea,r the edge is a circle of small hollows, into which the pieces of the metals are placed. The upper carbon would now come in contact with the top of the brass pin ; m order to bring the upper carbon above the hollows containing the metals, the top arm is provided with a slot to slide out. “ With this arrangement the spectrum of a number of metals may be projected on the screen in a few minutes with the greatest ease, the metals burning with an amount of steadiness I have not seen before. A piece of copper the size of half a pea was placed in one of the hollows, and completely burnt away without requiring any attention. “ The lamp I have is one of Browning’s, and acts most satisfactorily ; but the positive carbon is placed at the top. I find that in order to burn the metals with a steady light, the positive must be at the bottom ; when it is at the top, it invariably begins to vibrate after a little time, and sometimes throws the metal out of the cup. “ I have not yet noticed if this is the case when using the ordinary carbon cups. “The steadiness of the arc is probably due to the fact that the large mass of the carbon plate prevents it from becoming much heated, so that the convection currents (which I believe to be the cause of the arc, see Phil. Mag') have naturally a greater tendency to spring from the heated metal than the cold carbon.

“ So small is the heat developed in the carbon that it remains quite black, and maybe safely turned round with the hand/’ Dr Haast read an extract from the journal of Dr Hayden, attached to the United States Geological Survey, giving an account of the discovery of a peculiar species of hare, the male of which suckled the young. His Honor the Judge moved—“ That the council of this institute be requested to make arrangements for inviting Major Palmer, R.E., Lieutenant Darwin, and Lieutenant Crawford, to a dinner to be given to them by the institute, and that they be elected honorary members of the institute during their stay in New Zealand.” Dr Powell seconded the motion, which was agreed to. On the motion of Dr Powell, the honorary secretary read the following resolution passed by the Council“ That this Council records its emphatic protest against the publication of the paper by A. McKay, on the Sumner cave exploration undertaken by Dr Haast, and this Council requests the representative of this Philosophical Institute, W. Rolleston, Esq, to take what steps he may deem necessary to exclude it from publication in the Transactions of the Institute, in which paper the results of Dr Haast’s investigations are appropriated, and their publication forestalled,” Dr Powell said that if such things as this were allowed to be done, they could not with any degree of ,'self- respect remain affiliated to the New Zealand Institute. (Hear, hear.) He trusted the general meeting would approve the action of the Council in this matter.

The Rev C. Fraser moved—“ That this meeting cordially approves of the resolution of the council now read, and of the action proposed to be taken in preventing the publication in the Transactions of the paper by Mr McKay, as an attempted anticipation of Dr Haast’s paper on his own work, and that a copy of this resolution be forwarded to the several governors of the New Zealand Institute.” He might say that there was no desire to say anything here against Dr Hector, as he had not yet given any explanation of the circumstances under which McKay’s paper had been read by him. It would, therefore, be unfair to pass judgment until such an opportunity of explanation had been given. Mr Fraser then quoted the first paragraph of Mr McKay’s letter in reply to Dr Haast, pointing out that it contained an evident shirking of the true question at issue. Professor Bickerton seconded the motion, which was a'reed to unanimously. The Institute then adjourned.