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VI.-—Emperiments on the Preservation of Sheet Iron from Rustin India. By James Prinsep, Sec. 8;c.
The proposed entemive employment of iron steam boats for the navigation of the Ganges, rendered it a desideratum to ascertain what varnish or composition would best preserve the exterior surface of such vessels from the rapid corrosion to which iron is so peculiarly subject in a hot climate. A series of experiments was undertaken with this view by myself at the requisition of Government; and it 'may perhaps be useful to record the principal results in a journal of science.
Two sets of six wrought-iron plates, each measuring three feet by two feet, were fixed to two iron triangles, the plates being prevented by studs from coming into contact with each other. The same varnishes were applied to both sets-,0ne being intended for entire submersion under water, the other to be only half immerged, in order to feel the united influence of air and’ water.
The following were the coatings applied :
1. Common coal tar, laid on hot,~ and the plate heated.
2. Theetsee varnish of Ava, one coat. This took a very considerable time (two months) to dry, kept first in a cool‘-room, and afterwards in a room heated by furnaces*.
3. Native Dhdna, applied to the iron hot, in a thick uneven coat.
4. Best white-lead paint, three coats; allowed to dry and harden for nearly three months.
5. Coach-makers‘ varnish, two coats; dried rapidly.
6. Spirit varnish, several coats ; warmed.
7. White wax, melted on the surface.
8. White wash, of pure lime water.
9. The surface of the iron plate cleaned and guarded with an edging of zinc
soldered on. 10. The natural surface of the rolled iron sheets, coveredwith its usual hardened
Many of the foregoing were employed from curiosity‘ only, especially No. 6, the spirit varnish, which had on many occasions proved quite ineffectual in preserving the surface of polished iron and steel from rust in the atmosphere of Calcutta.
The two frames were suspended as above described, one under water, the other half immersed, from one of the unused dredging boats near the Chitpur lock gates of the Circular canal, where they were left undisturbed for three months, during a period of the year, when thewater of thecanal was only slightly salt.
* Major BUBNEY states, that three or four days are suificient for the varnish to dry when laid on wood, (Journal, Vol. I. p 172.) I had not a damp vault in which to expose the plate as recommended by that oflicer, and that may partly account for the delay in drying; but all varnish and paint takes longer to dry on metal than on wood, iromits non-absoprbent nature.
They were then taken up for examination, and presented the following appearances.
No. Varnish. Plates under water. Plates half above water. 1 Tar.. . . . . . . . Perfectly preserved and free A few dots of rust between from rust. wind and water. 2 Theetsee, . . . . Perfectly uninjured in ap- A line of rust at the level pearance. ‘of the water. 3 Dhoona, . . . . White and pulverulent ; Large cracks from the con
soft and easily rubbed otf while
traction of the part exposed to the sun, whitened where thick, black where thin; plate preserved, abovewaten 4 Paint, .. .. .. Almost wholly disappeared, Paint uninjured abovewater and blotches of rust on the mark, and plate preserved, but surface. below water entirely removed. 5 Copal varnish, Whitened, pulverulent, and In air less, whitened spots soft; but not much oxidated. of rust breaking out every
where. 6 Spiritvarnish, Whitened and very rusty. Very much corroded. 7 Was‘, . . . . . . No trace of wax left, and This plate was all under water. very rusty. 8 Lime, . . . . . . Flaky; peeled off, and very In air remains on and acts much corroded. pretty well. 9 Zinc, .. .. .. The clean iron excessively Much more rusty in the
corroded and bad: the zinc air than under water, where 8. also oxidated. kind of crust was formed. 10 None,.. . . . . The natural surface was a Rusty on the edges or where little whitened and prettywell it had been scraped; elsepreserved. where little injured.
The superior preservative power of the coal-tar to all the substances tried, with the exception perhaps of the theetsee, was evident ; the Burmese varnish laboured under the disadvantage of being a single coat, otherwise it would doubtless, from its hardness, its firm adherence, and its inalterability by water, prove fully equal as a lacquer to the coal-tar; the latter has on the other hand the advantage of drying and hardening as soon as laid on.
The change effected on the resinous varnishes is produced by an ac
tual chemical combination with the water; the soft pulverulent matter is analogous to the white powder obtained by the addition of water to an alcoholic or of acid solution of rosin. Y The failure of the zinc guard, which was expected to act as an electro-positive protector to the iron, may I think, be attributed to its being adulterated with lead, which being negative with respect to iron, would cause, as was actually the case, a more rapid oxidation of the latter metal : (the impurity of the zinc was afterwards fully proved.)
The wax and the white paint had entirely disappeared from the surface of the metal under water before the plates were taken up ; it is im-. possible therefore to say in what way their removal was effected.
The bituminous (coal-tar) coating was finally adopted, and it has been successfully applied to the iron steamer, the Lord William Bentinck, lately launched under Captain Jonusrorfs superi ntendence.
VII.-—Proceedings of the Asiatic Society.
The Right Reverend the Lord Bishop, Vice-President, in the chair.
Read the Proceedings of the last meeting.
Messrs. Wm. MARTIN and Tnonns Srmns, were proposed as members by Mr. Bnosnnw, seconded by Mr. J. Pnmsnr.
Also, Captain W. Fomsv, porposed by Mr. Pnmssr, seconded by Dr. Wnnmcn.
Read letters from Messrs. N. Cnnmsnn, Secretary to the Society of Antiquaries, and J. C. MournsA Secretary to the Madras Literary and Auxiliary of the Royal Asiatic Society, expressing the thanks of those Societies for the xvii. volume of Transactions.
Read a letter from M. J umss DESJARDINS, Secretary of the Mauritius Natural History Society, acknowledging his election as an Honorary Member of the Society. Mr. Cnnnm-:s Tenmm, President of the same Society, died before he became acquainted with the honor the Asiatic Society had equally intended for him. Mons. J. Dnsmanms forwards a 5th Annual Report of the Mauritius Society in manuscript for theAsiatic Society’s Library.
Read a letter from the Committee for concentrating Government oifices, inquiring on behalf of Government, whether the Asiatic Society would feel disposed to afford space in their rooms for, and undertake the charge of, the books belonging to the College Library, upon their removal from Writer’s Buildings at the close of the Charter, reserving the proprietory right of the books with Government.
It was the opinion of the Committee of Papers that the College Library could not be properly accommodated without some additions to the museum on the north of the building : this perhaps the Government might consent to make, as the books were to remain public property : in other respects the measure appeared highly desirable and the oifer should be accepted. The subject was dropped on an intimation that an arrangement had been made, subsequent to the Committee’s letter, for retaining the library in the premises it now occupies.
The following Books were presented:
The Indian Journal of Medical Science, No. 4.-—By Messrs. J. Grant and J. T. Pearson, Editors. '
Madras Journal of Literature and Science, No. 3.—By the Madras Literary Society.
Rnmcomun SEN’s English and Bengalee Dictionary, 2nd part, translated from Todd.’s edition of Johnson's Dictionary.—By the translator. .
Lieut. J. BR.ADDOCK’s Memoir on Gun-powder.—By the Author.
Proceedings of the Natural History Society of Mauritius, from July 1833, to January 1834.-By the Society.
Report on the Inland Customs and Town Duties.—By Mr. C. E. Trwelyan.
Illustrations of the Botany and Natural History of the Himflayan Mountains, kc. Part 1st.-—By J. F. Royie, Esq. F. L. S. G. S. and M. A. S. &c.
Mr. Bnesnnw stated that it would be a great convenience to Members
to have a revised catalogue of the library: whereupon, finding that the B B
former edition was nearly expended, it was Resolved, that a new catalogue be printed, comprising also the objects in the Museum.
Mn. J. T. Pnsnson, inquired whether any steps had been taken regarding the matter of compounding for subscriptions: Resolved, that a report be requested from the Committee appointed on the 26th June last, to consider the subject.
Read a letter from Major Bvnmrr, Resident of Ava, forwarding a collection of mineralogical specimens, consisting of :
Ores of lead, copper, antimony, iron and arsenic: and rock specimens, from the Shan country to the east of Ava.
Sulphate of lime, from the petroleum wells at Yenangyoung.
Specimens collected by Captain MACLEOD in a journey to Manipfir : of copper ore from Laypadoung on the Khyendwen river :—also of hornblende, volcanic rocks, and saline etflorescence from a sulphnreous lake called Myouk dwen (northern well) near Lemye on the left bank of the Khyendwen.
Also, coal from the Angoching hills, fossil wood from Taroup myo, left of the Irawadi river ; and the sand from which gold is washed at Kenau immediately above Kendat on the Khyandwen river.
Waters from the lake above mentioned and from a well in the neighbourhood (unexamined), and a root from Shan, smelling like celery, used with clothes to give them a scent.
Major Buunnr writes :——“ During my last journey up here I collected a good many fossil specimens near Yenangyoung, and particularly teeth of the Mastadon, and Elephantoides. Captain MACLEOD also during his late journey by water to Kendat(Gendah of our maps) found much of the country in that quarter indicating the presence of fossil remains, and picked up several portions of the jaws of the Mastodon, and Elephantoides with teeth. The Burmese ministers have ordered their oflicers at Yenangyoung to gather all the fossil bones they can for me, and as soon as I procure a large collection, I will send the whole to you for examination.”
A series of geological specimens from Southern India, was presented by Lieutenant Bnannocn on the part of a gentleman at Madras.
They consisted principally of :
Gneiss, greenstone, laterite, and magnetic iron ore from the Neelgiris.
The garnet-gneiss, of Coimbatoor and Salem.
The decomposing mica-schist, and gneiss ; yellow earth ;--felspar with magnetic iron, and quartz with ochreons clefts ;—-all which are washed (with or without previous burning) for gold, in the large gold district of Mysore.
Two handsome varieties of porphyry from Seringapatam.
Shell limestone from 12 miles W. of Pondicherry used for ornamental purposes.
Sandstone, slate-clay and other rocks of the Southern diamond formation, which have been fully described by Dr. HEYNE and Vovssr.
Specimens of the volcanic mud from Kyook Phyoo, presented by Captain ‘VARDEN.
The Secretary submitted a translation of the inscription in the Péli and
Burma character on the large monumental stone from Arracan, presented to the Society by H. WALTERS, Esq. in May, 1833 ; the notice of which at the time was deferred in expectation of receiving a translation and account from the donor.
The translation has been made by a native Christian of Ceylon named RATNA PAULA, who is well versed inthe Burma language, and who prepared the catalogue of Burma MSS. in the Society’s library.
The inscription (although very recent) is of considerable interest as describing the early history of the introduction of the Buddhist religion into Arracan from Ceylon, and the reform of various abuses in dress, and corruptions in the holy texts which had from time to time crept in. The principal object, however, is to commemorate the erection of a temple called Kalyani Simtolrri at Romdoaté in the island of Yanbya Koyan, in the year of Sakha raj 1148, (A. D. 1786.)
Read, letters from Captain CAUTLEY, forwarding a further supply of coins and other relics discovered in his occasional visits to the site of the subterranean town at Behat, with a plan of the neighbouring country, and an explanatory notice by the discoverer.
[This will be printed in our next.]
Captain GAUTLEY’S last letter notices that on a revisit to the spot at the Kalawala pass, where he had in 1827 made the discovery of what was then supposed to be a bit of fossil wood*, but which proved on Dr. FALCONEIVS examination to be bone, he has been so fortunate as to find another silicified bone, some teeth and a number of other remains, all apparently belonging to the Saurian family. Dr. FALCONER has also made further discoveries in the Timli pass, and we are led to expect an account of the whole shortly from the pen of the latter gentleman.
A memoir on the ancient coins discovered at Beghram in the Kohistén of Kabul, by (jnaanns Massozs, was read.
I [Printed in the present number.]
This highly interesting paper was communicated by Doctor J . G. German, who fell in with the author at Kabul. on his return from Persia. Doctor Gnnsnn founded upon the very successful issue of Mr. Mnssorfs researches a distinct proposition addressed to the “ President of the Meeting of the Society." ‘
The Right Reverend the Vice-President, proceeded to read Dr. Gn1tAnn’s paper to the meeting ; whence it appeared that two ofl‘ers were laid before the Society =
1. To employ Mr. Masson, on the part of the Society, to continue the prosecution of his researches in Afghanistan.
2. To secure by purchase the possession of the valuable relics he has already collected.
The two questions, as connected with the present means of the Society, were referred to the Committee of Papers for consideration and report.
A Memoir on the Topes of Afghanistan, by Doctor J . G. GERARD, also addressed to the Presiding Member of the meeting, was laid on the table.
A paper by Mr. B. H. Honosorr, Resident at Kathmandu, entitled Classificanon of the N éwéu-s, or aborigines of Népal proper, preceded by a legen_ dary account of their early history, was also submitted, but not read on
account of the lateness of the hour. ‘* See Asiatic Researches, Vol. xvii.