172 



NATURE 



\_July I, 1875 



connected by metallic rollers or brushes with two sta- 

 tionary conductors, which are insulated, and constitute 

 the poles of the machine. The currents obtained on 

 rotating the shell may be made either continuous or 

 intermittent, or they may be alternately reversed. The 

 iron cylinder itself may be rendered magnetic by coiling 

 upon it longitudinally an insulated wire after the manner 

 of the rotating armature of Siemens, 



To enumerate the possible applications of induction 

 machines would be simply to describe all the applica- 

 tions which have already been made, or may hereafter 

 be made, of current electricity to useful purposes. Among 

 the former, the electric telegraph, the electric light, and 

 electro-plating are perhaps the most important ; among 

 the latter, it will be sufficient to mention two proposals, 

 one to facilitate the ascent of steep gradients by in- 

 creasing, by means of magnetism, the adhesion of the 

 wheels of locomotives to the iron rails ; the other, to 

 decompose, by electrolysis, common salt so as to obtain 

 directly, and in a state of purity, the valuable chemical 

 products hydrochloric acid and soda. 



THE GOVERNMENT ECLIPSE EXPEDITION 

 TO SIAM 



THE following few details concerning the above Expe- 

 dition will probably be of interest to the readers of 

 Nature ; having just returned from Siam, I am unable 

 at present to give full particulars. The general results 

 obtained by our party have already been published in 

 this country by means of the telegraph. The fact that 

 any results were obtained at all is far more than might 

 have been expected considering the very brief time we 

 had to adjust the instruments. We had only five days to 

 land, unpack, fit up, and test the instruments, most of 

 which were quite new and untried. This want of time 

 was in the first place owing to unavoidable delays on the 

 way out, and to the fact that there was no steamer ready 

 to take us on to the Observatory Camp at once, thus neces- 

 sitating a visit to Bangkok prior to the eclipse. Our partial 

 success is in a large measure due to the valuable assistance 

 of Capt. A. J. Loftus, an English gentleman in the service 

 of his Majesty the King of Siam ; Capt. Loftus was sent 

 out by his Majesty to prepare the camp for us at Choulai 

 Point. 



As previous to our departure from London there appeared 

 in one of the leading journals a letter, signed " Monitor," 

 in which some very unpleasant statements were made 

 with regard to the probable reception our party would 

 receive in Siam — although Mr. D. K. Mason, the Siamese 

 Consul in London, published at the time a total denial of 

 the absurd insinuations — I feel it my duty, in the name of 

 all who took part in the expedition, to state that during 

 our prolonged stay in the kingdom of Siam we received 

 nothing but the greatest hospitality and kindness. Every- 

 body, from the King downwards, showed the greatest 

 desire to make our visit as pleasant as possible, and to 

 aid the expedition in every way ; difficulties were sur- 

 mounted at great expense and trouble, and everything we 

 asked for was at hand or was obtained with the least 

 possible delay. Our drinking-water was brought nearly 

 100 miles by water to the camp ; many tons of ice were 

 brought up from Singapore, and every kind of wine was 

 ready at hand. 



The King sent several of his officials, both European 

 and Siamese, to assist us, and ordered such observations 

 to be made at Bangkok as the chief of the expedition. 

 Dr. Schuster, might consider of use to the expedition ; 

 the King himself observed and made a drawing of the 

 corona. Our camp and observatory were situated some 

 fifty miles from the city of Bangkok, on the west of the 

 Gulf of Siam, in the central line of totality. On our 



arrival we found what had formerly been a waste of jungle 

 converted into a magnificent camp, and all the'houses fitted 

 up ready for our reception. 



The eclipse itself differed from former ones in respect 

 to the greater brightness of the corona and the smallness 

 and fewness of the red flames. As far as we could make 

 out, the time as calculated by the Nautical Almanack 

 was some ten seconds wrong. 



In a "Renter's" telegram, Dr. Schuster stated that 

 the spectroscopic cameras had failed. As failures arise 

 from many sources, this must be regarded as only a 

 general statement. It merely implied that no results 

 were obtained by these instruments, not that as instru- 

 ments for observing eclipses they were found to be a 

 failure. Several of the instruments were to have been 

 tested during the outward voyage, but owing to the 

 breaking-down of the Sttrat, and consequent transship- 

 ment of cases, no opportunity for such work was found, 

 and, on arriving at the camp, the time was far too short, 

 owing to other accidents, to enable anything like satis- 

 factory focussing and adjustments. 



There were two sets of instruments employed as tele- 

 spectropes, one working in the large observatory, the 

 other in the Siderostat Observatory, where we had the 

 large new siderostat working with Mr. Lockyer's gj-inch 

 reflecting telescope and a spectroscopic camera. The 

 first two instruments were in splendid order, working 

 together beautifully, but the spectroscopic camera, not 

 having been tested previously, could not be brought to 

 give anything like a well-focussed photograph prior to the 

 eclipse. The image of the corona, which appeared very 

 distinct and bright on the slit-plate, although exposed 

 during the whole of totality, gave no visible results on 

 the photographic plate ; even the sun itself, exposed 

 for two seconds for the purpose of obtaining an index, 

 gave likewise no result. 



Before making any statements on the results obtained, 

 I must wait the issue of the report of the Royal Society's 

 Eclipse Committee. 



Numerous drawings were sent in by the Siamese, which 

 will be very valuable along with the general observations. 

 After the eclipse, owing to three of our party being too ill 

 to leave, we remained longer in the city of Bangkok than 

 we had expected. During our stey Mr. and Mrs. Henry 

 Alabaster, our hosts, on behalf of the King, entertained 

 us in the most hospitable manner, taking care that those 

 who were ill should have all possible attention, and be 

 restored to health as fast as good doctors and kind nursing 

 could accomplish it. 



The following is a complete list of all who assisted us 

 in the observatories during the echpse, as well as of the 

 members of the expedition sent out, with the part taken 

 by each person : — 



The Expedition. 



Dr. Arthur Schuster.— Chief of the Expedition; in charge 

 of large Observatory, attending to the Equatorial. 



Frank Edward Lott. — Dr. Schuster's Assistant. In charge 

 of the Siderostat Observatory. 



F. Beazley, Jun. — Photographic Department. Developing 

 negatives in dark room No. I. 



Oscar Eschke. — Photographic Department. Preparing plates 

 in dark room No. 2. 



Officers from H.M.S. Lapwing, 

 Hon. H. N. Shore, Lieut. R.N. — Taking drawings of Corona 



in large Observatory. 

 Andrew Leslie Murray, Nav. Lieut. R.N. —Keeping 



time in large Observatory by Chronometer from H.M.S. 



Lapwing. 

 W. J. FiRKS, Assist. Eng., R.N.— Attending to the clock of 



Mr. Penrose's instrument. 



Europeans and Siamese from Bangkok. 

 Capt. A. J. Loftus, R.S.N. — Founder of the Observatory 



and Camp. In charge of Mr. Beazley's Camera, taking 



direct photographs of Corona with 2 — 4 — 8 — 16 seconds' 



exposure. 



