ant ey 4 an * ree é TRANSACTIONS = LOSOPHICAL SOCIETY | ae (Go be Yncorporatih ‘by Royal Charter, ) a. 5 a J. BLUNDELL & CO., COLLINS - TRANSACTIONS The Philosophical Society VICTORIA. A complete set of the, publications of the Royal Society of Victoria, up to the end of 1915, is offered for Sale by Mrs. T. S. Hall, Grantham, Kasouka Road, Camber- well, Victoria, widow of the late Dr. T. S. 3 Hall, formerly Secretary of the Society. The Set comprises : on f / Transactions, Victorian Institute for the « Advancement of Science, Wol. 1, 1855. / Transactions, Philosophical Institute — of Victoria, Vols. 1-4. 1855-1859. / Transactions and Proceedings, Vol. 5, nf entitled Transactions, 8vo., Vols. 5-24, 1860-1888. ah Proceedings (New Series), 8vo., Vol. 1-28. 1888-1915. The volumes are unbound -except for Nos. 4, 5, 6, 7, of the first series. | at ie TRANSACTIONS OF THE PHILOSOPHICAL SOCIETY VICTORIA, (€o be Intorporuted by Ronal Charter,) THE PAPERS AND PROCEEDINGS OF THE SOCIETY FOR THE PAST YEAR, ENDING IN JULY, 1855. MELBOURNE: JAMES J. BLUNDELL & CO., COLLINS STREET, EAST. 1855. MELBOURNE: Goodhugh & Trembath, Printers, Flinders Lane, East. “a NOTE. THE Papers contained in this Volume have been read at various times before the Philosophical Society of Victoria, from its inauguration in August, 1854, to its amalgamation with the Victorian Institute, and this volume is the first and only one of the kind that has ever been issued in Victoria. Perhaps some of the Articles are not exactly similar in their character to the publications of like Societies in Europe, yet it is hoped that the many facts now collected in this form will be found useful to those whose pursuits are in any way connected with scientific investigations. The Papers refer chiefly to matters of practical import- ance to the colony, but as they also contain recent discove- ries in Geology, Botany, and Zoology, they will be read with equal interest in other countries, altogether apart from their value as records of the advances made by the Colony in these departments of science. The names of the various contributors are attached to their productions, and they are each individually responsible for their opinions—the Society, in no case, having pledged itself to supp>t or verify these opinions. It is\probable that trifling errors may be discovered in the text, but assome of the members were absent while their papers were passing through the press, these must not be too Zz = vi harshly dealt with, nor charged upon those on whom it fell to revise and arrange the whole. . The Philosophical Society and the Victorian Institute, now united under the title of the “ Philosophical Institute of Victoria,” will continue to publish scientific Papers in a man- ner similar to this—the commencement of the series; and it is the duty of all true disciples of science to assist cheer- fully in adding to the variety and usefulness of the contents of their volumes. Melbourne, September, 1855. SUBSCRIBERS TO Che Gransactions of the BPhilosopheal Society VICTORIA. —. << —_§_|_|_— COPIES A. Abargill, T., 26, Queen Street the Adamson, Frederick M., 111, Little ars treet, West ae 1 Atchison, William, 30, Swanston Street ... ies eo soe 1 B. Bames, John, Post Office ee Barker, William, 93, Flinders Street, West Bayne, J., 48, Elizabeth Street u Bell, George, Union Freehold Land Sastely Bell, William, 121, Little Collins Street, West ... 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S., Pes Sleight, John, 71, Collins Siredt, Bast Sloane, Gibson & Co., 60, Market Street ory oe COPIES (Or Oe Beep ee Beep aS Se ee eS Subscribers. Smith, J. T., Mayor of Melbourne Smith, P. H., Inspector of Police, Richmond ... wae nee Smith, Robert, Fulton’s Foundry es set Soc Sorell, William, South Yarra Sutherland, D., Customs ... AoC T. Tarleton, James, United States’ Consul ... en ie Thomson, David, Cobourg Place, Gardiner's Creek Road Tidyman, J., 27, Collins Street, East ak eta Train, Geo. F., Flinders Street ... ae ize 56 Tralyn, D. M_., 27, Lonsdale Street ied His ae bs Turnbull, W. M., M.D, Spring Street ... V. Vaner, William J., Survey Office . orn Vescoe, John, Colonial Engineer’s Office cee W: Wagner, Louis, 71, Stephen Street Watt, John, Post Office Wedel, Charles, Criterion Hotel Westgarth, W., Market Street or Wilkman, Brothers ¢ Co., 106, Collins Street Willan, Robert, 38, Collins Street, Hast . Wilson, John, 31, Flinders Street ... Wilson, John K., 36, Flinders Lane, East Ss Wilson, Henry, Beehive Hotel, North Melbourne on Wilson, Thomas R., Chief Medical Officer’s Office Winter, Thomas L. M., 43, Bourke Street, Kast Wood, J. Dennistoun, 25, Temple Court ... Woolley, Richard, Chamber of Commerce Wrixon, Arthur N., 16, Temple Court Y. Youl, Dr. &., 45, Flinders Street COPIES 1 eee ee He pee BENS PE BP Pee Pe er eee TRANSACTIONS oF THE Philosophical Society of Victoria. Inaugural Address of the President, Captain Clarke, R.E., Surveyor-General, §c., &c. In accepting the office of your President, in now assuming the task of, for the first time, addressing your Association when launched on its course, I have been, not regardless of the responsibility I have taken upon myself, nor have I forgotten the absence of so many of those essential qualifications which would have rendered your selection less embarrassing to myself, or my address to you more worthy of the Society we seek to establish. / Not alone in the offshoots of the older world, but in the more ancient seats of learning, positions of this nature have customarily been occupied by men distinguished for their rank 2 Inaugural Address. or eminent for their learning, and it would therefore have been . most difficult for me to reconcile to myself my occupation of this place had I not felt assured of your recognition in me of those more humble, but perhaps not less useful qualities which may aid our common object, but in the language of one who had far less reason for using it under circumstances not unlike the present. I repeat that “in zeal for the welfare of this Association, in intense interest for the accomplishment of its object, I yield to none, and if these may suffice, I hope I shall not be found unworthy of the trust you repose in me.” Yet it is no common responsibility with which you have charged me, for this Association is one of the great powers which the altering phases of this world have called into action; yet a few years since and it could not have existed ; and even now some persons are found unable to appreciate its worth or understand Its purpose. And now may I be permitted to urge the necessity of that mutual support and co-operation upon which the progress and ultimate success of the Society is entirely based. From as simple an origin have the noblest institutions of our parent lands had birth, where their founders, however few their numbers, have shown that earnest perseverance which is the sure index of success; nor need we doubt our success in securing the same issue, for whilst every other interest is progressing with no ordinary rapidity, we may rest assured that the facilities for experiment and observation will become daily more attainable. If we look back upon the early history of the human family, when the arts of husbandry reigned alternately with those of warfare; and if we compare the comforts of life, and the means of intellectual enjoyment in those ages, with those of the present day, we shall perceive how vain it would be to attempt to measure the advantages which have resulted from the pursuit of knowledge and the ou of the natural sciences. Inaugural Address. 3 An enumeration of the items which supply our daily wants, and minister to our enjoyments, would at once show that the advantage which je thus possess, surround us so closely on every side, that, like the air we breathe, we direct to them the less attention on account of their invariable, presence. When we further note the amount of discovery and im- provement which each age in the history of man has con- tributed, it becomes apparent that the progress has partaken less of an arithmetical than a geometrical proportion. Hach discovery has opened a wider field for new discoveries; im= provement in one branch of knowledge has lent assistance to the development of every other, until the amelioration of the conditions of life, and the facilities of action have become such as to react, in no common degree, upon the available power of a single life devoted to the pursuit of truth. Thus while a knowledge of the nature and origin of disease has afforded the means of prolonging the average duration of life, the appliances of locomotive printing and other machinery have made that life of thrice its former duration, measuring it by the scale of the number of events for which it is available. But these extensive advances by no means show reason for relaxing our efforts, for while we are daily encouraged by important discoveries and a nearer approach to long desired truths, we are at the same time obtaining sight of a more widely extended horizon. With this stimulous to our efforts and mindful of the duty incurred by the acceptance of these bequests of exclusive knowledge, we must each endeavour to add his tribute to the common store. Reflecting that Australia is destined to fill no unim- portant part in the common history of a more advanced civili- sation, and remembering that Victoria in material wealth has made a century’s advance in the span of time which has elapsed since her foundation ; with this progress, the re- sult of one discovery, are we torest content? Should we not 4 Inaugural Address. rather question the continuance of this prosperity, recognising in it the means to a more desirable and higher end. The disturbances which we have experienced with our acquisition make room for the foundation of a future social greatness. Admitting this position, how can we advance this end? The difficulties of experiment in a new country will, doubtless, give additional importance to the culture of correct and minute observation. Who can predict the result which wili arise from the simplest’ discoveries? A stain upon a stone, a drop of coloured water, may prove of sufficient significance to fill the mountain’s solitudes with the iron life ofmachinery. Let us prove, rather than assert, the utility of research. Let us . enforce a due recognition of the labour of the inventor and discoverer until his national importance be acknowledged. And while thus in a general view, we cannot fail to see the value of those pursuits, how much more do they force them- selves upon our observation when we scan them in detail. The objects of our Institution will not be answered unless the geologist, the chemist, and the representative of the associated sciences conjointly labour to produce those results which have justly become the pride and glory of the civilised world. The mere mechanical arts are but the secondary results of science, and as accumulating facts, though necessarily laborious, are the first step towards eliminating truth; let us therefore sturdily arm ourselves to the acquisition of them, forgetting even what has been termed the sublimity of deductive philosophy, in the less honourable, but no less arduous and valuable, efforts of the practical experimentalist. Such labours, ever pursued under difficulties, seldom rewarded commensurately with their importance, it shall be’ our duty and our interest, to facilitate ; and while thus striving for these ends let us endeavour to secure, by singleness of purpose and unity of action, the general sympathy. Australian Plants. 5 Art. Il. Definitions of rare or hitherto undescribed Australian Plants, chiefly collected within the boundaries of the Colony of Victoria and examined by Dr. FERD. MUELLER. IF I venture to lay before the Philosophical Society a series of descriptions, by which a number of plants, but im- perfectly known or entirely new to science, are briefly illustrated, I beg to state, that in doing so I am only actuated by a desire of combining my humble acquirements with those of so many superior minds for the purpose of contributing perhaps towards that important object, for which this Society was formed, to diffuse useful knowledge throughout our adopted couutry, to elucidate its own productions, or to show how much a land, equally favoured by inexhaustible mineral resources, by aserene climate and most fertile soil, may produce, so that we may learn to appreciate those vast treasures, which as yet hidden and undeveloped are dormant in its virgin soil. In offering some results of my last researches to the Philo- sophical Society, I endeavour to fulfil those duties which every one of us has seriously taken upon himself injoining this union; although I must confess, that I only answered with hesitation the honourable call of commencing the series of dissertations, which we hereafter may expect before this auditory, and with which so many will adorn the annals of this Society, as I could not conceal from myself how inadequate my powers are for such a task. Only the thoughts, that science does not disdain the smallest gift, that the last links ofa long chain of observations are often closed by a most insignificant discovery, which isolated would be unimportant—only those thoughts could induce me to offer out of the botanical treasures of this country some novelties or rarities which rewarded my last explorations. I shall bring under review chiefly such plants as have en- larged genera, with but a limited number of species, such as 6 Australian Plants. have unfolded new disclosures in the affinity or geography of the vegetable kingdom, or such as have required an altered position in the system of botany, or such again as exhibit me- dicinal propertieslike Velleya, Trachycaryon, Beyera, Erioste- mon, and other Diosmeze; and not to scatter the connected observations I deemed it expedient to annex occasionally, also, notes and descriptions of allied species indigenous to other parts of Australia. RANUNCULACE. Myosurus Australis. - Scapi filiform or ‘setaceous, upwards but slightly thickened ; petals and sepals very small; fruitspike narrowly terete, somewhat acute, about an inch long; carpels numerous, closely imbricate, rhomboid or almost deltoid, acuminate, at the thickened base slightly spreading; styles very short. On moist places or in the open plains where rainwater lodges for a considerable time, near the Emu Creek, Hop- kins’ River, Avoca, Avon, Richardson and Murray, sometimes abundant. It is not little surprising that this genus, of which hitherto only two species, namely : M. minimus from Europe and M. aristatus from the Cordilleras of Chili have been noticed, should find its representative alsoin Australia. Our species is closely allied to M. minimus; it differs chiefly in the loose extracurved basis of the carpels. PITTOSPOREZ. Marianthus bignoniaceus. Innovation silky ; branches climbing, slightly pubescent, at length smooth; leaves patent, petiolate, out of an almost heart-shaped base ovate, oblong or lanceolate, apiculate, net- veined, above puberulous soon smoothening, beneath slightly hairy, at the margins undulate revolute, as well as on the nerve densely hairy; pedicels axillary single or two, rarely three together, at the base bractolate, of equal or twice the length of the petiole, as well as the calyx pubescent ; flowers pendu- lous; sepals lanceolate, accuminate, four or five times’shorter than the cylindrical, somewhat bell-shaped puberulous orange- yellow corolla; anthers yellow ; germen villoussilky; capsules narrow-elliptical, somewhat compressed, with a longitudinal furrow, biloculate, villous, cells many-seeded. Australian Plants. 7 On shady rivulets, cataracts, and in fissures of the rocks in the Victoria and Serra Range and the Grampians. In South Australia, on the Onkaparinga and in the Lofty Ranges. This remarkable and beautiful species extends the geogra- phical limits of the genus Marianthus to the eastern portion of this continent, and is the only one hitherto known from ‘beyond the boundaries of Western Australia. At the Gram- pians it is also accompanied with other features of the Swan River floraas Lepidobolus, Lhotzkya, Calectasia, not'previously observed towards the east. DROSERACEA. 3. Drosera angustifolia. (Sect. Arachnopus ) Stem foliate, simple, decumbent or adscendent; leaves scattered, nearly sessile, long and narrow caudate, above and along the margin glandulously pilose ; racemes, either opposite to the leaves or alternating with them, hardly of their length three-ten-flowered, covered with short gland-bearing hairs ; segments of the five-parted calyx lanceolate, gradually narrowed upwards, about equal in length with the capsule, and half as long as the whitish petals; styles 3, divided to the base, its divisions filiform, incurved at the top; seeds egg-shaped, clathrate. On the moist gravelly margins of the Lakes on the Murray River towards Eustone. This is the first extratropical species of this section of Drosera with which we are acquainted. It approaches next to Drosera Finlaysoniana from Cochinchina. But this is only one of the many tropical forms of plants, which, transgressing the torrid zone, advance so far southerly as the Murray desert. POLYGALEZA. 4. Comesperma polygaloides. (Sect. Disepalum. ) Smooth; leaves approximated, flat, narrow or linear-lan- ceolate, acutish, glaucous; racemes somewhat dense, purple; pedicels shorter than the flowers; lateral bracteoles about half as long as the intermediate one; lobes of the anterior sepal acutish ; carina gibbous at the top, hardly shorter than the wings. . In barren plains at the Avoca, Guichen Bay, and Encounter ay. In its chatacters approaching to C. emulum; in its habit to C. calymegum. 8 Australian Plants. VINIFERZ. 5. Cissus Australasica. Leaves palmate, quinquefoliate ; leaflets coriaceous, stalked, smooth, oval-lanceolate, acuminate, towards the top remotely serrate or entire, below glaucous; the paniculate cymes or the tendrils shorter than the opposite leaf or equally long ; flowers four-parted. On the wooded banks of the Broadribb River. This second Australian species, which forms a high climber,: appears to agree best with Cissus diversifolia of Candolle, (not Walpers.) SAPINDACES. — 6. Dodonea procumbens. Branches prostrate ; twigs hardly angulated; leaves some- what scabrous, flat, cuneate, grossly three-toothed at the top; pedicels at the summit of the twigs solitary or rarely two or three together, shorter than the leaves, as well as the calyx hirtellous ; flowers dioecious, pentamerous, with a long style; capsule with three broad rounded wings. In subsaline flats and peaty places at the foot of Mount Sturgeon and Mount Abrupt. This Dedonaea is with facility recognised by its procum- bent growth, and the extremely long style which generally measures one inch. 7. Dodonea deflexa. Upright, somewhat scabrous, viscose; twigs angulated, patent; leaves coriaceous, nearly round or ovate, repand and undulate at the margin, and sometimes remotely toothed, truncate or rounded at the top; flowers di ecious, auxillary, solitary or geminate; pedicels deflexed, shorter than the leaves ; sepals ovate, nearly round ; capsule truncate, with four or five wings, which are expanded upwards. In the desert scrub along the Murray River and Spencer’s ulf. 8. Dodonea bursarifolia. Smooth, not viscous; twigs indistinctly angulated; leaves coriaceous, nearly opaque, flat, obovate, cuneate, blunt, rarely apiculate or emarginate, alwaysentire ; flowers dioecious, axillary, and terminal, solitary, or two and three together; sepals, oblong-linear; anthers whitish; capsule three or four sided, with extremely narrow wings; seeds shining: black. . Australian Plants. 9 In the barren scrub-country on the Murray and St. Vincent Gulf. This species agrees in many points with Dod. trigona and Dod. aptera. ZYGOPHYLLEZ. 9. Tribulus acanthococcus. Prostrate ; leaves longer than the peduncles, with generally five or six pairs of leaflets, which are oblique, ovate-lanceolate, approximate and in size almost equal to each other, subsessile, beneath appressed hairy ; flowers decandrous ; petals obovate, exceeding somewhat in length the narrow-oblong sepals; anthers ovate; rays of the stigma reflexed, half as long as the thick style; fruit depressed, consisting of 5 puberlous, tri- seeded carpels, which are in the middle bispinose, on the back crested and hairy, at the commissure lacunose, and are destitute of a wing. On the sandy, loamy, arid plains along the Murray and Murrumbidgee, towards their junction. Only one Australian species has been previously described from this genus, T. Hytrix, R. Br. in Sturt’s exp. into Centr. Aust., II, app. p. 69 (T. lanatus, Walp. annal. II, 243,) for the discovery of which we are indebted to the enterprising Captain Sturt. LIOSME A. Asterolasia. Anew genus of Diosmex. Flowers hermaphrodite, solitary sessile. Sepals 5,petaloid. Petals 5, membraneous, diminutive or wanting. Stamens 10, hardly exceeding the length of the calyx. Filaments alternately shorter. Anthers erect, inap- pendiculate, fixed at the base, bilocular, cells bursting longitu- dinally. Style simple. Stigma deeply five-cleft, with filiform or clavate lobes. Germina five, concrete, with two gemmule, affixed to the central angle. Carpels five, tomentose, one- seeded Seeds, strophialate. Australian shrubs, resembling — Phebalium species, covered with stellate hair, in allusion to which the generic name has been formed. This splendid genus is exactly intermediate between Cho- rilena and Geleznowia. It differs from the former in its in- florescence, smooth filaments, basifixed anthers, and smallness er absence of petals. Through the last character it approaches to Geleznowia; but the stigma of the latter is undivided or- | bicular ; and this character is supported by a habitus ex- tremely alienate. Two species have been hitherto discovered. 10 Australian Plants. ‘10. Asterolasia phebalicides. Branched; leaves sessile, oblong or obcordate-cuneate, retuse, on both sides tomentose, with flat margins; sepals golden-yellow, excelling twice or three times the length of the carpidia; petals wanting; lobes of the stigma filiform, only a little shorter than the hairy style; seeds opaque. On the stony declivities of the Grampians, the Serra and Victoria Ranges, particularly frequent on Mount Sturgeon and Mount Abrupt. 11. Asterolasia trymalioides. Much branched ; leaves coriaceous, ovate, on short petioles, above glabrescent, beneath tomentose, with revolute margins ; sepals of equal length with the carpidia, twice or three times longer than the petals; lobes of the stigma clavate, much shorter than the smooth style; seeds shining. On the rocky summit of the Cobboros mountains in the Australian Alps, at an elevation of more than 6000 feet above the level of the sea. Here, at so apt an opportunity, I adjoin the diagnosis of a second and very remarkable species of Chorilena, occurring in the interior of New South Wales. : 12.. Chorilena angustifohio. Leaves as well as the branches covered with stellate hair, approximate, oblong-linear, blunt, on short petioles, with re- volute margins, at length glabrescent, scabrous; corymbs capitate-terminal; bracteoles linear-filiform; sepals broad- linear, half as long as the corolla, externally somewhat hairy, connate at the base; filaments smooth, surpassing in length the narrow-lanceolate petals; style smooth; stigma puncti- form; germina five distinct, narrow, perburulous. 13. Eriostemon hillebrandiz. Diffuse or upright; leaves oblong, ovate or heart shaped, truncate or short bilobed at the top, with recurved serrate or entire margin, on both sides smooth or somewhat scabrous on the surface; corymbs terminal; sepals minute, deltoideo- ovate; filaments of subequal length with the petals, as well as the style smooth ; anthers inappendiculate ; carpels obliquely ovate rostellate; seeds even and somewhat shining. A, brevifolius, diffuse, leaves ovate or cordate, 2-4” long, imperfectly toothed or with entire margin. On the rocky banks of rivulets in the Victoria Ranges. B, longifolius, strictly upright, leaves oblong serrate, up- wards of an inch long. Australian Plants. ll On the rocky summit of Mount William, 5,000 feet above the level of the sea. ; This highly ornamental plant forms a connecting link be- tween Phebalium and Eriostemon, and has been described by Dr. Lindley as a species of the former genus (under the name of Phebalium bilobum) in Sir T. Mitchell’s third expedition, vol IT., p. 178. sce It might be almost considered as a genus distinct of both; and South Australian specimens have been under these con- siderations distributed with the name of Hillebrandia Aus- tralasica. 14. Crowea exalata. Much branched, upright or diffuse ; twigs indistinctly angu- late, wingless, puberlous; leaves alternate or fasciculate, broad- linear, gradually towards the basis narrower, blunt, minutely apiculate, with recurved margins; pedicels of sub-equal length with the calyx, solitary; petals rose-red. On the rocky tops of Mount M‘Farlane, about 5,000 feet above the sea; on the gravelly banks of the Mitta Mitta and Livingstone River towards Lake Omeo, and on the Boggy Creek in Gipps’ Land. Easily to be distinguished from Crowea saligna, by thicker much smaller leaves, which are not gradully narrowed at the top, by wingless twigs and smaller flowers. 15. Boronia coerulescens. Suffruticose ; stems upright, branched, terete; leaves thick, sessile, oblong linear, obtuse, channelled, beneath glandulose- tuberculate; pedicels axillary and terminal, solitary, thick- ened at the apex, sub-equal in length to the leaves; flowers octandrous ; sepals oblong or lanceolate, of less tlan half the length of the bluish petals; filaments ciliate; seeds reticulate- venose. A, glabrescens: branches, leaves and pedicels smoothish, scabrous; flowers smaller, with acute lanceolate sepals. In barren places from the Mallee scrub on the Murray River to Spencer’s Gulf. B, pubescens: branches, leaves and pedicels short-pube- scent ; flowers larger ; sepals oblong, obtuse. On rocky hills in the Grampians, and in the desert towards Guichen Bay. 16. Boronia veronicea. (Zieria veronicea Ferd. Mueller, Coll. ) Covered with a velvet-like indument; leaves approximate, 12 Australian Plants. simple, ovate or subcordate, blunt sessile, with revolute margin ; flowers tetrandrous, axillary, solitary, on short pedi- cels, forming at the end of the branches a foliate raceme ; sepals acute lanceolate, half as long as the corolla; filaments hispidulous; carpels elliptico-oblong, compressed, pubescent. On sandy places about Encounter Bay and in Kangaroo Island. . By this interesting species the genus Zieria becomes united with Boronia, to which I am also inclined to refer Cyano- thamnus. 17. Boronia clavellifolia. Fruticose, diffuse, much branched, smooth; branches tu- berculate ; leaflets small, ternate, short-stalked, sub-clavate, terete, blunt; flowers axillary and terminal, solitary, ge- minate or ternate, octandrous; pedicels shorter than the flower; sepals ovate-triangular, ciliolate, less than half as long as the corolla; filaments smooth, glandulose. On sandy, loamy plains in the scrub near Lake Lalbert and towards the mouth of the Murray River. MALVACEAE, 18. Stda intricata. Fruticulose, upright or diffuse, much branched; leaves small, ovat-roundish, truncate at the top, toothed, but entire at the cuneate base, above scantily, beneath densely covered with grey stellate hair, petiolesmuch shorter than the leaves, surpassing in length often the subulate-setaceous stipules, peduncles axillary, solitary, drooping, shorter than the leaves ; segments of the calyx subdeltoid; carpels five, a little depressed, on the back almost even and puberulous, at the commissura netted ; seeds brown, puberulous. In sandy, loamy plains between Mount Hope and the Murray, also towards the Darling River. It bears some affinity to Sida corrugata, but its growth is upright intricate, it is much more robust, the flowers and leaves and capsules are much smaller, the latter not rough. 19. Sida humillima. Suffruticose, procumbent; leaves thin, ovate-oblong, obtuse, cordate or rounded at the base, unequally and deeply crenate, above scantily, beneath densely covered with a stellate some- what shining indument; petioles hardly of the length of the leaves, but longer than the subulate-linear stipules; peduncles axillary, solitary or two or three together, filiform, towards the middle articulated, sub-equal to the length of the petiole ; Australian Plants. 13 segment of the calyx subteltoid, acute; carpels, eight-ten, depressed, rough, smooth at the commissura asperous; seeds ‘brown, smooth. In dry plains on the Avoca and Murray. In South Australia, on St. Vincent Gulf and the Kapunda. Not dissimilar to Sida corrugata. 20. Abutilon Behrianum. Stem herbaceous, upright, hardly branched, as well as the leaves covered with a velvetlike toment; leaves cordate, acuminate, repand or slightly crenate, about as long as the petiol ; stipules linear-subulate deciduous; peduncles axillary, solitary, one-flowered or terminal with several flowers, above the middle articulated, often shorter than the petiol ; segments of the calyx ovat-lanceolate acute; carpels 9-12, tomentose- pubescent, compressed, oblique-ovate, aristote, with 2-4 black somewhat scabrous seeds. In lagoons which become dry, and.on the margins of lakes on the Murray, Loddon, Darling, and Murrumbidgee. 21. Abutilon otocarpum. Fruticose, upright, all over grey-velutinous; leaves cordate- orbiculate, blunt, inequally crenate, of nearly equal length with the petiol ; stipules linear-subulate, deciduous ; peduncles axillary, solitary, one-flowered, towards the top articulate, but little surpassing the length of the petioles; segments of the calyx inflated, cymbiform, long acuminate; carpels numerous, shorter than the calyx, very compressed, earshaped, nearly membranaceous, velutino-pubescent, with one to three black glabrous rough seeds. Very rare on Sandhills on the Murray towards the junction of the Darling. This Abutilon stands in some relation to Ab. halophilum (Ferd Mueller in Linnza xxv., p. 381) from Spencer’s Gulf. ScLERANTHES. 23. Mniarum singulifiorum. (Scleranthus mniaroides Ferd. Mueller collect.) Stems caespitose, somewhat flaccid ; leaves upright or little patent, as well as the branches smooth, levigate; peduncles one-flowered, at the top bibracteate; calyx turgid, 5-cleft. On bare rocks at the summit of the Cobboras mountains, 6,000 feet above the level of the sea. Easily to be distin- guished by the above notes from Mniarum biflorum (M. 14 Australian Plants. fasciculatum R. Br. Scleranthus Mniarum Ferd. Mueller), the only known species, and like this varying in the length of the peduncles. By the constantly 5-cleft calyx of this kind Mniarum becomes so closely allied to Scleranthus, that hardly any objection can be raised against the conjunction of the two genera. PoRTULACE. 22. Mollugo Novo-Hollandica. Stems numerous, prostrate, dichotomous ; leaves pseudo- verticillate, unequal, spathulate-lanceolate, at the top indis- tinctly serrulate, finally grabrescent, young ones together with ‘the branches woolly-pubescent; flowers triandrous, pseudo-verticillate ; sepals blunt, a little longer than the ovate capsule, and about equal in length to the pedicel; seeds reni- form-ovate, shining brown, densely seriato-granulate. On the sandy sometimes inundated banks of the Murray. This presents the first Australian species of this genus, and must be systematically placed next to Moll. hirta trom the Cape of Good Hope. EUPHORBIACEZ. 24. Phyllanthus trachyspermus. Annual, smooth, glaucous; stem upright, branched ; branches angular ; leaves imbricate, deciduous, oblong, obtuse, on very short petiols; pedicels solitary, very short; sepals lanceolate-acute, much shorter than the capsule, with broad membranaceous margin; stigmata very small; capsula sub- globose, smooth, drawn out into an umbonate apex; seeds large, livid, acut, triangular, at the internal angul deeply excavate, on the sides and back rugosely asperate. On places subject to inundations at the junction of the rivers Darling and Murray. 25. Phyllanthus lacunarius. Annual, smooth, glaucous; step upright, branched; branches angular; leaves imbricate, deciduous, obovate- or cuneate-oblong, obtuse, on short petiols; flowers monoecious, axillar, solitary, on short pedicels; sepals minute, subovate, obtuse, with broad membranaceous margin; stigmata very short ; capsule depressed, trigastrous ; seeds trigonal, blackish with longitudinal streaks. On the margins of lagoons which become dry during sum- mer, at the junction of the Murray and Darling rivers. Australian Plants. 15 26. Phyllanthus Fuernrohri. Fruticulose, upright, branched, with a grey velvet-like indu- ment; branches nearly terete; leaves imbricate, deciduous, spathulate-obovate, on very short petiols, apiculate ; pedicels axillar, subsolitary, half the length of the leaves ; sepals lanceo- late-ovate, acutish, with membranaceous margin, outside as well as the depressed capsule hairy scabrous; seeds brown, levigate. On gravelly sandhills near the Murray, rare. This species received its name in grateful acknowledgment of much kindness, which the author experienced from Pro- fessor Fuernohr, in Ratisbon. 27. Trachycaryon Klotzschii. Leaves opposite, very short stalked, ovate-lanceolate, acute, irregularly crenately toothed, serrate or repand, above smooth or imperfectly puberulous, beneath grey-velutinous, at the base of the petiole on both sides furnished with one or two small stipitate glands; femal flowers apetalous ; sepals ovate, subacuminate ; styles free, hardly to the middle bifid ; capsuls verruculose, ovate-globose, slightly impressed at the suturas ; seeds grey, ovate, shining. On sandhills near Corner Inlet, and in various localities in - South Australia. 28. Trachycaryon Cunninghami. Leaves alternate, in circumference lanceolate-ovate or heartshaped, short- or deep-tripid, smooth or below tomentose, irregularly and coarsely serrate, at the base truncate or rounded, with acute lobes and teeths, on the base of the petiole’ furnished on both sides with one or two large stipitate glands ; femal flowers apetalous; sepals lanceolate, acuminate; styles free, deeply bifid; capsuls subglobose, not furrowed at the suturas; seeds spotted. A, TOMENTOSUM ; Leaves short-stalked, below as well as the twigs and capsuls tomentose; bracts and sepals ciliate. B, GLABRUM; _ Leaves long-stalked, as well as the capsuls sepals and bracts smooth. Between granite rocks and on the sandy banks of the Snowy River. To variety A belongs probably Adriana acerifolia of Allan Cunningham, and to B, A. heterophylla of Sir William Hooker. 16 Australian Plants. 29. Trachycaryon Hookeri. Leaves alternate, long-petiolate, lanceolate-oblong, gra- dually narrowed into the base, acute or obtuse, smooth or grey velutinous, irregularly crenate-tooth or bluntly lobed, at the base of the petiole on both sides beset with a small gland; femal flowers apetalous ; sepals ovate-lanceolate, acut; styles at the base connate, deeply bifid; capsule trigas- trous, glabrescent. A, velutinum ; Leaves above thinly, below together with twigs and flowers thicker velutinous. B, glabriusculum ; Leaves on both sides smooth, twigs and flowers glabrescent. On sandridges along the Murray, towards the junction of the Darling and the Murrumbidgee. 30. Beyeria opaca. Smooth; twigs compressed, yellowish-green; leave narrowly or linear-oblong, rounded-blunt, gradually narrowed into the base, hardly viscous or shining, with flat or slightly recurved margins, above light-beneath pale-green ; pedicels of subequal length with the calyx; capsuls ovate-globose, hardly furrowed at thesuturas; seeds shining, variegated, with a thick caruncula. In the Mallee scrub, between Lake Lalbert, Lake Tyrrell, and the Murray River. MYRTACER. 31. Lhotzhya genethylloides. Flowers terminal, nearly capitate; leaves crowded, exsti- pulate, spreading, petiolate, without stipules, tetragonal, at length above flattening, subobtuse, as well as the twigs and the tube of the calyx hirtellous; bracteols shorter than the penta- gonal tube of the calyx, connate to the middle and ‘apiculate by the excurring carina. In rocky arid declivities of the Grampians, the Serra, and Victoria Ranges. B, glabra ; Dwarf, leaves almost smooth. On the subalpine summit of Mount William. I do not hesitate to refer to this species Genethyllis alpestris, of Lindley, (in Mitchell, Three Expeditions, vol. ii., p. 178,) described from specimens, collected by Sir Thomas Mitchell on Mount William. These specimens, transmitted to Professor Australian Plants. 17 Lindley, were probably not well developed, being gathered in the month of June. Examining the plant last year in the month of November, I became convinced that it belongs to the genus Lhotzkya. Ihave neither retained the specific: name alpestris, as the plant occurs most abundantly on the lower parts of those mountains, and in lotalities much exposed to the hot north-westerly winds. CUCURBITACE. Cucurbita micrantha. Stems prostrate, angulose, simple, as well as the petioles strigosely asperous; leaves subcordate, with 5 short blunt dentato.sinuate or incised lobes, on both sides hirtello- asperous, on the margin and beneath along the nerves densely strigulose ; tendrils short undivided; peduncles axillar, fili- form, fasciculate, much shorter than the petiole, with the calyx pubescent ; flowers monoecious ; berriesglobose, even, smooth, manyseeded. On the sandy-loamy banks of the Murray, sometimes washed by the floods. The fruit might, on account of its intense bitterness, per- haps be substituted for colocynth. GENTIANEZ. Limnanthemum crenatum. Leaves cordate-orbiculate, crenate, obsoletely palmatinerved, above even, beneath densely glandulose; segments of the calyx narrow-lanceolate, less than half as long as the corolla, exceeding but little the length of the capsule; segments of the yellow corolla on tho margin and orifice fimbriate, inside longitudinally broad-cristate ; style thick, abbreviate; stigma with five lacerate wings ; hypogynous glands fimbriate; capsule polyspermous; seeds ovate, laevigate, hardly keeled. In tranquil bends of the Murray river, Murrumbidgee, and Mitta Mitta, and in the nearest lakes and lagoons. A most handsome, and, with regard to its crenate leaves and the structure of the stigma, equally singular species. GOODENIACEZ. Velleya, R. Brown. Sect. Aceratia. Calyx five-parted. Corolla violaceous, hardly gibbose, with wingless underlip and half-winged upperlip. 18 Australian Plants. 34. Velleya connata. High, glaucous, smooth; stem upright, dichotomous, with Bewded: ole : leaves all radical, elongate-lanceolate, onenerved, entire, contracted in a petiole of equal length; bracts very large, almost deltoid, acute, half concrete, entire; segments of the calyx lanceolate and ovate, accuminate; style villose ; seeds densely punctuate, surrounded by a broad wing. On scrubby sandhills towards the junction of the Murray and Murrumbidgee. This highly curious plant also possesses the tonic bit- terness which I discovered i in numerous species of Good- eniacez. SOLANACEA. 35. Solanum lacunarium. Armed all over with setaceous-subulate straight prickles ; stem dwarf, suffruticose, branched; leaves petiolate, in cir- cumference oblong-ovate, sinuate-pinnatifid, above conspersed with stellate hair, at length calvescent ; beneath as well as the branches covered with a thin orey toment ; lobes of the leaves oblong, rounded-blunt, with entire margin; peduncles terminal, 2-6-flowered, seneene ; segments of the calyx acutish, deltoid-lanceolate ; anthers yellow. In lagoons which are dry during the summer season near the junction of the river Darling and Murray. It differs from Solanum cinereum (R. Br. prodr. i., 446), the only one to which it bears similarity, in its blunt entire leaf-lobes, which are together with flowers and berries con- siderably smaller, by almost considerably armed peduncles and pedicels, and by hardly cuspidate segments of the calyx. 36. Solanum pulchellum. Unarmed; stems procumbent, suffruticose; leaves on somewhat long petiols, ovate-or-narrow-oblong, bldnt, repand, entire, above pale green, laxely tomentellous, below clothed with a shineless, thin, grey toment; peduncles 2-5-flowered, generally surpassing the length of the petiole; calyx half as long as the corolla, earinulate, with triangular acuminate segments ; ; anthers yellow, slightly attenuat, surpassed in length by the style. Along the Wimmera, Avoca and Murray rivers; thence through the desert-country as far as Lake Torrens, Spencet’s and St. Vincent gulfs. Australian Plants. 19 Allied to Solanum dianthrophorum (Dunal Sol. 183) and to an undescribed species discovered in Central Australia by Capt. Sturt, of which I subjoin the definition : 37. Solanum Sturtianum. Stem upright, fruticose, scantily armed with short acicular prickles ; leaves on somewhat long petioles, lanceolate-oblong, blunt, entire, unarmed, above glabrescent, beneath clothed with a very thin toment; peduncles 3-5-flowered, generally surpassing the length of the petiole; calx much shorter than the coralla, with triangular, acute teeths; anthers yellow, attenuate. Another species brought from the interior of this island- continent by the same intrepid traveller, might be characterized as follows,— 38. Solanum oligacanthum. Stem upright, fruticose; branches beset with distantly scattered setaceo-subulate prickles; leaves small, cordate, obtuse, entire. on both sides as well as the branches covered with a very thin grey toment, hardly armed, short-stalked; pedundes 2-or many-flowered, short; calyx half as long as the corralla, with deltoid acute segments; anthers yellow, excelled in length by the style. This series approaches to Solanum orbiculare (Dunal syn. 27), from ‘which it differs chiefly in its not shining toment, and its exact heartshaped somewhat larger leaves. To complete my additions to the elaborate description of more than 900 Solanum species, published by Prof. Dunal in the 13 vol. of Candolle’s prodromus, I beg to add yet the diagnosis ofan unknown South Australian species, having also given since an account of three others in Prof. Schlech- tendal’s Linnaea (vol. xxv. p. 432-434). 39. Solanum simile. Unarmed, smooth; stem upright, suffruticose; leaves narrow-lanceolate, elongate, entire or lobed at the base, thin- venose; corymbs lateral, few-flowered, simple or divided ; segments of the half five-parted calyx rounded, apiculate ; berries globose, nodding. On less fertile plains on the Murray and Angas river, on Spencer’s and St. Vincent gulfs, and in Kangaroo Island. It is distinct from Solanum laciniatum in its constantly 20 % Australian Plants. low stem, smallness of all parts, its never pinnatifid leaves, its shorter nodding pedicels, and smaller always spherical berries. I conclude these contributions towards the Australian Solanez with the remark, that this order received by the first and ever memorable expedition of the unfortunate Dr. Leichhardt the addition of the genus Datura (in Datura Leichhardtii), and by the researches of Dr. Behr the addi- tional genus Lycium (in L, Australe), both unnoticed not only in the golden prodromus of R. Brown, but also in Dunal’s monographia published in 1852. LOGANIACEAE. 40. Mitrasacme distylis. (Sect. Lysigyne. ) Annual, minute, glabrous; stem upright, simple or a little branched, smooth; leaves oblong-linear, somewhat carnulent; , pedicels axillar and terminal, setaceous, solitary, rarely two or three together, at least twice as long as the leaves; calyx bellshaped, very short bilobed, not excelled in length by the corolla; styles separated ; capsule inclosed; seeds not-veined. Around swamps near Mount William. In stature re- sembling Mitrasacme paradoxa, but from this as well as all the other species widely different in its disjoint styles. BoORRAGINEAE. 41. Heliotropium lacunarium. Stems herbaceous, upright or procumbent, appressed-hairy; leaves somewhat long petiolate, oblong-or lanceolate-ovate, nearly blunt, entire, not rugose, on both sides scabrous, beneath along the margin and nerve pilose; spikes ternate geminate or solitary ebracteate; segments of the calyx sub- equal to each other, of the length of the corolla-tube ; caryop- sides subovate, rugose, glaprous. ‘ Around the lagoons, and in low localities on the Murray. SCROPHULARINAE. 42. Anthocercis myosotidea. All over hirtellous from short gland-bearing hairs; leaves small, sessile, ovate, blunt, broader towards the base, un- equally revolute ; pedicels shorter than the hirtellous calyx; Australian Plants. 21 segments of the calyx semiovate, blunt, twice shorter than the tube ; corolla half-exserted, with short blunt lobes. In gravelly sandridges on the Murray, but only rare. A species next to A. scabrella, but well marked by the short blunt corolla. yo 43. Anthocercis angustifolia. © All over glandulously pubescent ; leaves linear, flat, entire ; pecidels of equal length to the calyx; segments of the calyx linear, acutish ; lacinie of the large corolla lanceolate-linear, acuminate, nearly twice as long as the tube. ° In stony glens near Mount Lofty in South Australia, not frequent. PROTEACE. 44. Grevillea dimorpha. ~ (Sect. Calothyrsus. ) Diffuse ; branches angulate ; leaves coriaceous, undivided, long-lanceolate or linear, acute, callously mucronate, almost sessile, trinerved, above smooth, on the recurved margins and the lateral nerves somewhat scabrous, beneath grey-silky ; racems fascicular on very short peduncles; calyx almost three times longer than the pedicels, outside rutilous-silky, inside at the middle white bearded; style long exserted, together with the germen and its stripes perfectly smooth; stigma lateral, ovate centrally umbonate. A, latifolia, leaves ovate- or narrow-lanceolate, 2-4” long, 4-8” broad, rarely broad. B, angustifolia, leave elongate-linear, 2-4” rarely 6” long, 1-13’” broad. In the Grampians, Serra, and Victoria ranges on barren rocky places. This splendid species bears much affinity to Grevillea Victorie; it is however readily distinguished by its thicker subsessile generally narrower leaves with a distinct marginal scabrous nerve, by its short racemes on an abbreviate peduncle with rusty brown rhachis, by its smaller flowers inside nearly up to the limbus barbate, and finally by smaller folliculs tapering into a longer stripes. It flowers in the spring, not as Grevillea Victorie in the autumn. 22 Australian Plants. 45. Grevillea confertifolio. (Sect. Lissostylis, ) Diffuse ; twigs pubescent ; leaves crowded, linear-subulate, even, short-mucronate, above smooth, beneath with the inno- vations silky; margin refract to the on both sides prominent middle-nerve; fascicules of flowers sessile, terminal, concealed by the leaves; calyx outsides and its pedicel grey tilky, side at the middle densely bearded ; pistil hardly half an inch long, smooth, exserted; germen stipitate; stigma ovate, oblique- terminal, with central papilla. On the subalpine summit of Mount William, and on rocky ridges towards Mount Zero. This species resembles Grevillea juriperina and G. reparia (R. Br. prod. 377.) 46. Grevillea lobata. (Sect. Eugrevillea. ) High, upright, many branched; twigs spreading, angular, covered with a very thin whitish indument; leaves in circum- ference ovate, deeply laciniate, venose, with hardly recurved margin, contracted by a wedge-shaped basis into the stalk, above pale-green, glabrescent, beneath tomentose as the branches; segments two or three on both sides, distant, lanceolate, mucronate, entire, rarely teeth-bearing ; racemes dense, ovate, many-flowered, at length drooping ; calyx out- side as well as pedicels and rhachis grey from an appressed indument, inside smooth ; style long exserted, with exception of the basis smooth; hypogyne gland very short; stigma oblique-lateral, broad-ovate, centrally umbonate ; germen and its stipes white-tomentellous. In the desert along the Murray river, from Swan Hill away to the westward. Nearest to Grevillea ilicifolia (R. Br. suppl. p. 21), but much higher, upright, tomentum white shineless, not silky, leaves deeper, divided with distant segments, and flowers more numerous. 47. Grevillea pterosperma. (Sect. Cycloptera. ) Upright; branches strict, holosericeous; leaves glaucous, somewhat rigid, narrow-linear elongate, undivided or bi- tripid, glabrescent, ending in a sphacelate, mucrone above Australian Plants. 93 convex and manifestly striated; margin refract to the beneath very prominent middle nerve; racemes alternately crowded at the end of the branches, elongate, dense-flowered, calyx outside with pedicels and rhachis grey pubescent, inside to- gether with the style smooth; germen stipitate, tomentose ; stigma ovate, oblique-terminal centrally umbonate; folliculi globose-ovate, turgid, hardening with a short stipes, grey tomentellous ; seeds flat, ovate, even, all-around winged with a thin membrane. In the Mallee scrub on sandhills towards the junction of the Murray and Murrumbidgee. Allied to several tropical species, particularly to G. augus- tata (R. Br. suppl. p. 24). POLYGONZ. 48. Polygonum diclinum. (Sect. Avicularia. ) Suffruticose, glaucous perfectly smooth; stems upright, many branched ; leaves linear, at both ends narrowed ; stipules short, binerved, entire smooth, laxely clasping; fascicles axillary, few-flowered; flowers dioecious, octrandrous and trigynous, greenish, imbricate-bracteolate, cernuous ; pedicels shorter than the 5-parted glandless calyx; caryopsis sub- globular-trigone, shining black, hardly rugulose. On shifting sandhills at the junction of the Murray and Murrumbidgee, and rarely at the Mitta Mitta. SANTALACE. 49. Choretrum chrysanthum. Branches terete; twigs angular, not pungent; leaves almost persistent, lanceolate-subulate, at length somewhat deltoid ; glomeruls yellow, 2-5-flowered, on the top of lateral very short twigs; bracteols 3 subovate or roundish, ciliolate. On low scrubby ridges along the Avoca and Murray river. Not dissimilar to Choretrum glomeratum, from which as well as the few other already known species it is easily dis- tinguished by its golden flowers. ERIOCAULONE. Electrosperma. A new genus of Eriocaulonee. Flowers in androgynous heads, all furnished with a bracteola. Receptacle conical, — 24 Australian Plants. as well as the bracteolae smooth. Male flowers central pedicellate. Sepals smooth, the three externals coherent at the base; the three internals concert in a long tube, the free lobes bearing a gland. Stamens six inserted to the limbus. Anthers bilocular, introrse. Female flowers marginal on short pedicels, destitute cf a calyx. Style, one, short, with three filiform stigmata. Capsule smooth, tricoccous, loculicide dehiscent. Seeds in the cells solitary, smooth, not costulate, of the structure of Eriocaulon. This genus is chiefly characterised by the want of the floral envelope in the female flowers, but agrees otherwise in habit and structure with Eriocaulon. The name is derived from the colour and shining transparency of the seeds, not unlike that of amber. 50. Electrosperma Australasicum. On wet places along the Murray, towards the junction of the Murrumbidgee. te A small annual scapebearing herb.. Leaves grass-like, fene- strate nerved, pellucid. Scape monocephalous, vaginat at the base. Art. III.—On the comparative value and durability of the Building Materials in use in Melbourne. By Robert Brough Smyth. THE selection of building materials has always been a work of difficulty, as indeed is every branch of knowledge, where the experience of a single individual is substituted for those simple principles which arise naturally from an accumulation of facts, —not the records of one life time, but of many,—not of one department of science, but of all. The mistakes that have been made from time to time, as evidenced in the decay of _some of the finest architectural works in Europe, have drawn’ considerable attention to the subject of late years; and that such mistakes may, in a great measure, be provided against, if not wholly prevented, we have the evidence of the Scientific Commission appointed to examine the stone to be used in the New Houses of Parliament, and of the Corps of Royal En- gineers, whose sound and practical observations, founded on actual experiments, are worthy of the highest consideration. It not only has immediate reference to the conservation of those edifices wherein the genius of the architect is para- ri Building Materials. 25 mount, but is so connected with our wants and necessities, of a common kind, that we cannot but injuriously sacrifice it to consideration of cost, time, and convenience. . As this paper will treat more particularly of the building materials used in Melbourne, it is necessary to remark that the geological character of the district is similar to that from whence are derived some of the best building stone in Great Britain. The prevailing formation is inclined sand- stone and clay slate, changing so much in its lithological character that, had we not clear and satisfactory evidence of its antiquity, it might sometimes be mistaken for a recent ‘ deposit. We find it in every variety of sandstone, from a coarse grit to that of a fine, close-grained structure, which last passes into a claystone, containing very few quartz grains, and a little white mica. Overlying this, and extending through a considerable area, is the Basalt, or “ Bluestone,” which is well adapted to structural purposes, and generally obtains where durability is desired. The rock is recognised by geologists as a vol- canic product, and may be considered second only to the Plutonic rocks, in its wide distribution and economic im- portance. BASALT. The specimens that I have examined differ very little in their composition as far as it effects their durability ; though the proportions of their chemical constituents are variable. - It is composed of angite, felspar, iron, and lime, with occa- sional crystals of olivine; and the contact of these minerals is close and perfect. The most common colour is greyish blue. ‘The fracture is uneven. An analysis shows its com- ponent parts to be—* Silex te by hs 50 Alumina Pe is ae 22 Carbonate of Lime ah 10 Magnesia... at a 4 Tron .. a ah ei 10 Loss .. nh bs ie 4 It sometimes contains traces of other metals, but this analysis gives its most important constituents. The average weight of a cubic foot is 165 lbs., the maxium being 167 lbs., and * The figures in this analysis must be considered only as approximate; my appliances not being of a kind to ensure rigid accuracy. 26 Building Materials. i the minimum 164 lbs. It does not absorb so much water as might be supposed from its structure. After immersing an average specimen for 96 hours its increment in weight was 1°751 per cent.; anda mean of various experiments made on stones procured from the neighbouring quarries approach very nearly to this result. Were it not that this stone was exceedingly costly, both in obtaining it from the quarry, and inall its subsequent stages, it would be used in this Colony in preference even to granite. In addition to its value asa building stone, it is quarried for road metal and kerbstones, for which it is peculiarly adapted, and that is perhaps the best proof of its durability. The styles of architecture adopted in Melbourne, where Basalt is used, are not generally favorable to its appearance ; where it has received some degree of finish it is extremely handsome, and it is to be regretted that it has not been chosen for our public buildings. Basalt may be advantageously employed in the composition of mortar. When it is calcined and reduced to powder, it imparts to the cement the property of hardening under water. SANDSTONE. The Sandstones which I have examined are by no means favorable specimens of the formation which they represent. In general they have been procured at or very near the surface,’ and from the quality and properties of such specimens very. erroneous opinions have been formed of their nature. In the older formations, and here I would allude to an age antecedent to the Carboniferous era, it must be remembered that the surface of the strata has been exposed for countless ages to incessant changes; and the alterations which it has undergone will extend to various depths in exact proportion to the structure of the rock. The term “ metamorphic,” as used by geologists, is applied to rocks which have been altered by the effect of heat. Little attention has been paid to changes which take place by infil- tration, by the decomposing effects of air and water, and other causes, requiring lengthened periods of time for their com- pletion. Inclined strata, of a schistose structure, are more liable to such alteration than the comparatively undisturbed deposit of a coal basin; and though I am far from attributing the perishable nature of the Melbourne Sandstones wholly to Building Materials. 27 these causes, they undoubtedly have exercised an influence more powerful than we are at first inclined to admit. The Sandstone procured from Irrewarra, in the parish of Boroondara, singularly contrasts will other beds in the im- mediate vicinity. Though, as will be shown, it is neither so durable nor so valuable in other respects as the Geelong Sandstones, it is a proof that the changing character of the beds needs only to be noted and followed to lead to other deposits of a better description. The block which has been handed to me for examination is composed of coarse quartz grains, much water worn, agelutinated by an argillaceous and siliceous cement. Its shades vary from pale cream color to nearly pure white, and it is irregularly traversed by red and brown ferruginous streaks and spots. It yields readily to the hammer in the direction of its cleavage, as is usual with stones of this class. The average weight is 155 lbs. per cubic foot. Its capacity of absorption is so great that that alone is a sufficient reason for its rejection as a material for large buildings. After im- mersing a portion of the block, weighing 55°85 ozs. for 72 hours it absorbed 3-043 per cent. by weight, and another experiment on a smaller piece gave 3°217 per cent. B simple immersion, allowing it to remain till air bubbles had ceased to escape, the results were as follows :— Experiment, No. 1, 2°542 per cent. ” 2, 2-320 ” 9 3, 2194 ” Thus, it only absorbs a large amount of water, but what speaks more strongly in its disfavor, such absorption is carried on very rapidly. This stone has been subjected to a variety of tests, some of which it isnecessary to particularize. A small specimen of the average quality was immersed ina solution of a carbonate till it had absorbed the maximum quantity ; it was then placed ina weak solution of acid: this gave rise to brisk effervescence, and frequent repetitions of this resulted in the destruction of the surface of the stone. This test I have found valuable in practice: it is needless to state that it can only be used when the cement is not of a calcareous nature. Another series of tests were instituted by immersing the stones in solutions of various salts, and then suspending it over the vessel containing the fluid. After this process was many times repeated the salt re-crystalized in the stone; and the 28 Building Materials. mechanical force thus exerted very gradually effected the disintegration of the surface. A good building stone would long resist such experiments, for it itis manifest that if the amount of water absorbed was incon- siderable, the mere crystallisation of the salt upon the surface would produce little or nochange. In estimating the durability of a building-stone it is particularly necessary to note what quantity of water it will absorb, and whether it long retains moisture. ‘This is a matter of primary importance where the frosts are severe and of long continuance, and it ought not the less to enter into our calculations, for we have climatic variations in this country which tend almost as rapidly to disintegration. Water requires its greatest density between the temperatures of 39° and 40° Fahrenheit, from which point both heat and cold cause expansion. Here, where we have sometimes a deluge of rain succeeded by extreme heat, it follows that the mere expansion of the fluid rapidly exerted, must cause the destruction of an absorbent body. If we observe the rocky bed of a river or creek where the water and the sun have alternately acted upon the stone it will be seen that the surface is, in every case, in a state of decay, sometimes to the depth of several inches. This ’ illustration is drawn from the highly indurated Trappean , rocks which abound in our neighbourhood. How much more liable are the ordinary Sandstones to such influences. We must also take into account the dew which falls very heavily throughout some months of the year. Moisture absorbed in such a state will tend to lower the temperature of the walls, and that again is as quickly raised during the day. It is the continual repetition of these influences which ultimately destroys the cohesion of bodies so constituted. An accurate analysis of the Boroondara stone would give those constituents which are found in some of the best Sandstones, but that does not in itself afford us criteria whereby we may judge of its value. It is more dependent upon the mechanical structure, due to compression, and the unretarded progress of those chemical changes which tend to consolidate the mass. My meaning may be better understood by examining its fracture. We do not find the particles of quartz shivered and split, but they uniformly separate from the cement, leaving perfect casts of the imbedded grains. The freedom with which this stone may be wrought into Building Materials. 29 almost any shape, and its cheapness compared to basalt or - limestone, render it suitable for cottages or other small build- ings, where there is no great pressure on the walls; but all building stones of similar properties ought to be rejected in extensive erections. The Toorak sandstone, as I am informed, is from the same formation as that of Boroondara. It is composed of very fine water worn quartz grains, and minute plates of white mica, with an argillaceous base. It is deeply tinged with iron oxide in patches and streaks; none of the specimens in my possession being of a uniform colour. The weight of a cubic foot is 145 lbs.—the maximum being 147 lbs., and minimum 143 lbs. It is easily frangible. It may be wrought in large masses. Itabsorbs water very quickly, and to a great extent. It gains 3°952 per cent. by weight if immersed for’a few minutes ; and a piece that was placed on its end in water for ninety-six hours showed an increment by weight of 5:109 per cent. In comparing the sandstones, one with another, it will be observed that some very rapidly absorb their maximum quantity of water, and others very slowly. The close grained sandstone from Geelong, for instance, gains ‘336 by simple immersion, but the actual amount that it will absorb, if sufficient time is allowed, may be stated at 3-831. Subjecting the Toorak stone to the usual tests it is soon destroyed. Such of the specimens as I have met with are not suitable for building purposes, all of them possessing features similar to the above. A small piece that was placed ina vessel containing sufficient water to moisten the lower por- tion, was soon completely saturated, the cavities of the stone acting like so many capillary tubes. With such a stone for outer walls a house would be always damp and cold in winter ; a matter of deep importance to the health and well-being of the occupants, which ought ever to enter into calculations of this kind. A deeper section of this quarry may probably afford a less perishable material, and such a discovery would be of the greatest value at the present time. For durability, beauty, and economy, the sandstones are undoubtedly of the first class. The lightness, and architectural elegance of the buildings in Edinburgh, which are so famous, are due to the circum- stance of the sandstones there being procurable of a superior quality. Perhaps it would be impossible to construct such edifices of any other material, which at once combines hard- 30 Building Materials. ness, strength, and impermeability, with a peculiar richness of effect. As an example of the waste of labour and capital which sometimes results from using an untried sandstone, I may cite the case of an enterprising citizen of Melbourne, who some ten years ago built an hotel of a material quarried from the extensive formation to which the Boroondara stone belongs. Within three years after its completion the stone was found to be so far decayed that it became necessary to pro- tect the walls with a facing of another material. This is suffi- cient to illustrate the practical utility of inquiries such as these. Major-General Sir John Burgoyne, in speaking of this class. of stones, has thus expressed himself:—“From the nature of the composition of sandstones, it results that their resistance against or yielding to, the decomposing effects to which they are subjected, depends to a great extent, if not wholly, upon the cementing substance by which the grains are united; these latter bemg comparatively indistructible. . Uniformity of colour is a tolerably correct ériterion of uniformity of structure, one of the practical ex- cellences of “ building stones.” BRICKS. The great effects attending the working and procuring of building stone in this City, has led to the adoption of Bricks as a convenient and ready substitute. Very little attention has been paid to their manufacture, as a detail of the follow- ing experiments will show. I have procured my specimens from large buildings which are at present in course of erection, with the hope of drawing attention to a matter of such importance. These Bricks are composed of clay which has resulted from the decomposition of clay slate and Basaltic rocks, and that again is mixed with a large per centage of siliceous earth, washed down from the more recent formations which form the capping of the adjacent hills. The fracture is rugged and uneven, showing the presence of embedded quartz pebbles, with occasionally pieces of unmixed talcose clay of a pure white colour. They are light and porous, and readily yield in any direction to a slight blow. The specific gravity is 2°078, and compared with other Bricks is as follows :— Ramsay’s Fire Brick, Newcastle-on-Tyne, 2°204 White Brick, Launceston, ae .. 29153 Building, Materials. Haine: They absorb water very rapidly: one specimen gaining 11-523 per cent. by weight in 20 hours, and another 13-257 per cent. When it had absorbed its maximum quantity it was easily crumbled between the fingers. A good brick does not absorb so much water as the Melbourne sandstones. One of Ramsay’s manufacture was immersed for 20 hours, and its increment was 2°841 per cent., and after 72 hours 3-216 per cent. Subjected to the ordinary tests the common red Brick very rapidly disintegrates. It may be inferred that a small amount of force would be required to crush it; and it is a matter of‘regret that I have no present means of ascertaining the exact weight. Such a material is certainly not suited for buildings three stories high; and yet a considerable number of houses in this City are so constructed. There is a very slight difference in the quality of the _ Melbourne Bricks. The fault is owing not so much to the material of which they are composed, as to the improper man- ner in which they are manufactured. They are usually burnt im clamps, and the clay is not ground and tempered as is customary in other countries. If suitable kilns were erected, and care was taken in the preparation of the raw material, it would be possible to make as good Bricks in Melbourne as any that are imported, excepting perhaps the fire bricks. Bricks which are made of pure clay, and heated to vitri- fication, have been found to resist atmospheric influences most completely. Such a material is unsuitable for high walls, as its cohesive strength is not so great as when a pro- portion of sand is used. The best English bricks are manu- factured from a clay which contains about one-fourth of sand, and if it should contract considerably in burning, the pro- portion of the latter is increased. Much of the fine clay around Melbourne contains lime and magnesia, but not in excess; and if it were mixed with the superficial clay at present in use, a manifest improvement would be apparent in the bricks. All materials of this manufacture are rendered more durable by glazing. This is effected by throwing a due proportion of salt into the furnace, the result of which is the vitrification of the outer crust. When the manufacture is otherwise imperfect, this system, if properly conducted, will lessen the tendency to decay, and obviate the unsightly and expensive system of painting, which is often resorted to in Melbourne. Not until we have the same spirit that animates the manufacturers in England and America will this branch of industry, be fully developed. Machinery has there super- 32 Building Materials. seded the slow and tedious operations of hand moulding and smoothing, and the work of one man is now equivalent to that of six under the old style. The fashioning of bricks is not the only use to which the plastic clays areadapted. The fabrication of draining pipes and tiles employs a large capital in England, and the success which has there attended the manufacturer has been of incalculable value to the Agricul- turist. It has sufficed to bring under cultivation many thousand acres of larid, thereby increasing the demand for labour in all classes, and proportionably lessening the evils due to a surplus population. The Melbourne bricks, as they are now manufactured, will be too costly when we shall have brought in the aid of machinery. With the ordinary appliances, a mill, a moulding machine, and kilns, the clay in this neighbourhood could be wrought into pipes for sewerage, flower-pots—indeed into every article, whether of utility or ornament, for which there is such a demand; and not of an inferior quality, but quite equal to what is imported. If time permitted I would willingly advert to the manifest ‘ dangers attending the use of ill-burnt bricks in large build- ings, such as hotels, stores, &c., &c. . It is not a matter entirely confined to the occupant and the proprietor. Many of these edifices abut upon our public streets and promenades, and though in all probability the greater number of them will be taken down ere many years pass away, it would be a much better state of things if done forethought preceded their erection. In concluding this paper, I would beg reference to the accompanying Table, wherein I have stated as accurately as possible, under present circumstances, the most characteristic properties of the Melbourne Building Materials :— * 33 Building Materials. SSS, ‘aaAemm pur ySnor omjavlT “"yxee snoeoyis pue Ley Jo posodmoy “oN XIMLpB USIe10F Jo epyqT] ygtm ep oug wv jo pasodutoy ‘uvajo pus dreys amg “OBL “poyttytA Avpo-oay Aareurpso Jo posoduoy “moppes-ysthard ‘mopop ‘sasod -md surppmq sof ofqeyms Aza A “UvISeMOR TT “WMO SNOULSNIIEZ Yep puv yy Sry “IWMSOII Moog ‘aseq snoaorypFae ue YIU Svorur OPM Jo soquid [Teas pue surerS zyaenb oul, ‘sjods puv syvoays snoursna1ay yy OTA “Ystaorak “moog ‘yueure snosors pur SNO0dov] [Lory "worur 9]99IT & pute ‘suread zq1enb asavog ‘umorq-Yysthers anojog “queut -00 SNOSDRTLSIW ‘Wom pue 109;eur snouruimgig ‘pasoduosap sjereurur esoyy pue “reds[oy “BOLO YIM ‘sureas ZyIwnb out, —*saasvayy [eop “Apyenb pooy ‘uadoun aanqoury *a.M4X04 OSOT.) ‘a1quimp Ar9A ore aqraes8 Suoja05 oq} Jo SOJOMVA OULOG ‘oz A-YstXors Mojo) +seqwIpoyxa Ayprdea vor ayy se ‘Aq1enb pooS Jo 40 NI *qoazr0d Ay[eioues woweyog "worm YOoRlq Jo uowyaodoad asie] B YA ‘2A.1enb pue avdspaz jo pasoduiog SS “NOTLd14OsSaa 9&&-0 81-0 410-0 “yma9 jod uoydiosqy | 19d nomdiosqy jo Ajtoedeg WONULUT AT TE8-8 Sh 691-0 eicie) jo Aytoedeg TUNWxe Ay 889-2 *AVARID oyloadg wzayT sereeereees omLmOglaWT—OUE Pay s*** ToysooUNU—yoIg O41] AA auky,-uodn-apjsvomeN—youg oat PO cecenseeee ec *Su0jeen—ouojsourry [e100 T,—ouojspueg sereeeess pisptoolog—euojspusg eteeeee eeeeseees StioTaaK)—ouoqspurg “see esses eereees ormogiayy—ITeseq Leeeececerccece (2) Sopa 9j—ojzue1y . ‘STIVIUHLVN ONIGTIING NO SLNEWIYTIXT JO TIGVL 34 Australian Plants. Art. LV. Definitions ofrare or hitherto undescribed Australian Plants, chiefly collected within the Boundaries of the Colony of Victoria, and examined by Dr. FERD. MUELLER. (Continued. ) CRUCIFERZ. 1. Cardamine laciniata. Perennial, erect, glabrous; leaves nearly all radical, on long petioles, lanceolate, remotely toothed or laciniate or sometimes pinnati-partite; flowers in the raceme remote; petals oblong-cuneate,' hardly twice as long as the sepals; siliques as well as their pedicels spreading; style short; seeds brown, slightly wrinkled. On moist grassy as well as on boggy places, along rivers and creeks; it often indicates a saline soil. 2. Sisymbrium cardaminoides. (Sect. Arabidopsis.) Annual, diffuse, somewhat hairy; leaves lanceolate, entire or on both sides with one or two teeth; pedicels expanded, hardly half as long as the silique; nerve of the valves thin; petals white; filaments linear-subulate; style short; stigma indistinctly bilobed. On sandridges near the entrance of the Murray River. 3. Capsella antipoda. (Sect Hutchinsia. ) Annual; stems simple or little branched, ascending, foliate ; leaves all petiolate, pinnately parted or entire, glabrous ; lateral lobes two or three on each side, ovate or oblong, the terminal one larger; petals white, ovate; unguiculate; calyx for some time persistent, half as long as the corolla; silicles elliptical, shorter than the pedicles, 4-12-seeded; stigma subsessile. In the Black Forest, and on the summit of Mount Alex- ander. Of great affinity with Hutchinsia petrea. 4, Lepidium ambiguum. (Sect. Dileptium.) Perennial; stem upright, branched, somewhat scabrous ; Australian Plants. 35 upper leaves lmear, entire or with a tooth at the apex and with a broad basis, sessile; flowers furnished with petals; silicles of the length of the pedicels, ovate-oblong, attenuated at the apex, with a very short emarginature, which includes the subsessile stigma. On the Murray River in South Australia. Allied to Lepi- dium hyssopifolium; silicles 2 lines long. 5. Lepidium monoplocoides. { Sect. Lepia.) Perennial; stems upright or ascending, branched, scabrous from small papule; leaves linear, entire, slightly tapering into the base; flowers without petals; silicles orbicular, acuminate, with a broad keel, a little longer than the flat pedicel, their lobules connivent, surpassing in length the style. In the Mallee Scrub on the Murray River, towards the junction of the Murrumbidgee. A rare species, almost intermediate between Lepidium and Monoploca. 6. Monoploca leptopetala. Fruticulose; branches numerous, scabrous; leaves’ semi- terete; petals lanceolate-linear, long acuminate; silicles ovate, of equal length with the pedicel; their lobules at the extremity connivent, half as long as the style. in the Murray desert not unfrequent. 7. Stenopetalum sphaerocarpum. (Sect. Camelinella. ) Glabrous; stems filiform; lower leaves of the stem tripartite, their segments and the upper leaves linear, entire; pedicels filiform, nodding, longer than the calyx; petals white, exceed- ing with its linear curled appendage twice the sepals; silicles globose, nerveless, hardly of the length of the pedicel; each cell containing from six to eight seeds; funicles shorter than the seeds. On moist sandy places on the Murray River, at Lyndock Valley, Crystal Brook and various places on Spencer’s Gulf. BUETTNERIACE. 8. TLhomasia petalocalyx. T. macrocalyx of Schlechtendal, (Linnea xx. p. 633.) not of 36 Australian Plants. Steudel. Hispid from starry hair; leaves petiolate, oblong, entire, blunt on the summit and rounded on the base; stipules large, foliaceous, oblique, ovate or half cordate; racemes lateral, simple, few-flowered; segments of the hypocalycine bracteola lanceolate; petals five or wanting; germen short- downy, pointed; style glabrous, as long as the anthers, which are at the top short-dehiscent ; capsule three-celled. On coast rocks of Wilson’s Promontory, on scrubby places of the Bugle Ranges, and on the Gawler and Murray River. The first species known from the eastern portion of Australia. 9. Lasiopetalum Behrit. Leaves coriaceous, narrow-oblong, obtuse, above at length perfectly smooth, beneath covered with a velvety grey-brown toment; cyme few-flowered, about as long as the opposite leaf; basilar bracteole linear, the upper one tripartite and half as long as the calyx, with unilateral linear scarcely unequal segments; lacine of the calyx outside starry grey- hairy, inside smooth, ovate-lanceolate, acute; germen blunt, white velutinous. In the Mallee Scrub on the MurrayRiver and St. Vincent’s Gulf, where it was at first observed by Dr. H. Behr. 10. Corethrostylis Schulzenii. Leaves thin, cordate, somewhat acute, above asperulous, beneath grey-green and thinly tomentose; cyme about as long as the opposite leaf; bracteoles linear-filifiorm, undivided, solitary, the upper one a little remote from the calyx, which is whitish, almost membraneous, marcescent and not spotted ; petals opposite to the filament, smooth or outward hairy; germen white from glandless velvet hair; style with excep- tion of the summit densely retro-pilose. In the Salt Flatt at Guichen Bay and on Mount Benson. Intermediate between C. membranacea and C. cordifolia from the western coast of Australia, to which part of the country the genus was formerly considered restricted. STACKHOUSIACE, ll. Zripterococcus spathulatus. Smooth, stems branched, ascendent; branches almost terete, streaked, foliate; leaves fleshy, oblong or obovate-spathulate ; Australian Plants. 37 flowers nearly sessile; unguis of the petals longer than their lamina; style tripartite. On the rocky and sandy shores of Wilson’s Promontory, of Rivoli Bay and Lake Alexandrina. LEGUMINOS&. 12. Acacia tenuifolia. Procumbent or rarely erect, twigs soon terete, hispidulous ; leaves scattered, opposite or sometimes fasciculate, spreading, often retroflexed, linear-subulate, rigid, pungent, nearly tetragonal from the prominent nerve, hardly tapering into the base, glandless, scabrous; stipules setaceous, persistent 3, peduncles solitary or twin, smooth, about as long as the leaves; heads globose, many flowered ; sepals ciliolate, nearly three times shorter than the four-parted corolla; pods glabrous, linear falcate, hardly between the seeds contracted; seeds shining, supported by a conduplicate thick brownish strophiole. In dry stony ranges near Ballarat, towards the Goulburn and Broken River. It stands in relation to A. Brownii, and varies like many other species with downy leaves. 13. Acacia Wilhelmiana. Viscidulous; stems angular, puberulous; phyllodia ineur-- ved, upright, short linear-filiform, compressed, ending in a broader blunt recurved apex, above or on both sides furrowed and furnished with two thin veins; stipules ovate, acuminate, very glutinous, deciduous or at length spinescent; peduncles axillary, solitary, shorter than the flower-heads; pods viscid, narrow, arcuate, between the seeds slightly contracted. In the Mallee Scrub on the Murray, where it was first discovered by Mr. Wilhelmi. E Allied to Acacia Hookeri. 14. Oxylobium procumbens. Podolobium procumbens, Ferd. Mueller, first gen. rep. tL. "i Fruticulose, procumbent; leaves opposite or rarely ternate, lanceolate or round-ovate, flat, entire, prickly pointed, soon glabrous; stipules setaceous, reflexed; umbels terminal, pe- dunculate, few-flowered, sometimes compound; _bracteoles, affixed to the base of the calyx, long persistent; calyces 38 Australian Plants. scantily clothed with short grey hair; germina silky ; pods stalked, many-seeded. On wooded hills; for instance, at Mount Disappointment, in the Goulburn Ranges, on the Delatite, in the Black Forest, at Balaarat, &c. This plant and several allied species tend to show, that the distinctions drawn between the genera Chorizema, Podolobium and Oxylobium are merely artificial. 15. Oxylobium alpestre. Fruticose, diffuse or erect; leaves ternate or opposite, oblong-lanceolate, entire, sharp-pointed, soon glabrous, on the margin recurved; stipules linear - setaceous, reflexed ; umbels terminal, pedunculate, few-flowered, sometimes com- pound; bracteoles affixed to the base of the calyx, deciduous; calyx short grey-hairy; germina densely silky; pods villose, short-stalked, few-seeded. Not unfrequent in the higher parts of the Australian Alps. 16. Pultenea Bentham. Robust, erect; twigs angular, somewhat silky; stipules lanceolate -subulate, concrete at the base; leaves nearly flat, coriaceous, lanceolate or oblong, awnless or ending ina sharp point, either smooth and even on both sides, or below silky; petiole very short; heads terminal, few-flowered, surrounded at the base by imbricate brown, ovate, or round- ish ciliolate bracteas; bracteoles navicular - lanceolate, with exception of the margin, smooth, brown, scarious, affixed to the tube of the whitish silky calyx; upper-lip of the calyx short - bilobed, considerably shorter than the lanceolate subulate laciniz of the lower lip; germen, together with the basis of the style silky. On springs and rivulets in the Grampians, and amongst rocks on the top of Mount Abrupt. This elegant species, which stands nearest to P. myrtoides All. Cunn., has been named in honour of Mr. George Bentham, the eminent monographer of this class of plants. 17. Phyllota pleurandroides. Twigs pubescent; leaves recurved, spreading, linear, sharp ointed, scabrous, with refract margin, the floral ones crowded and below the middle villose; flowers concealed between the Australian Plants. 39 leaves, either axillary, solitary, or collected in terminal few- flowered heads; bracteoles ovate, keeled, shorter than the tube of the silky calyx; standard surpassing considerably the length of the keel, but little that of the wings; style below the middle appressed- hairy, unbearded on the apex; pod somewhat hairy, ovate, slightly compressed; seeds destitute of a strophiola. In arid plains, at the foot of Mount Abrupt, in Kangaroo Island, and Encounter Bay. 18. Burtonia subalpina. Twigs almost silky, soon glabrescent; leaves crowded, undivided, filiform, channelled, awnless, smooth, scabrous; stipules longer than the petiole; flowers sessile, terminal, capitate; calyx and germen villose-silky; corolla purple; style below hardly broader. On the rocky summit of Mount William, at an elevation of about five thousand feet. Not dissimilar to B. diosmifolia, from which it differs as well as from all other Western Australian species of the genus in producing stipules. The pod is yet unknown. 19. Bosstaea distichoclada. Erect, unarmed; branches and twigs in two rows, terete, grey-velutinous, densely foliate; leaves small, on very short petioles, bifarious, assurgent, coriaceous, nearly kidney-shaped, at the top awnless and divided into two very short lobes, their margins recurved, above scabrous, on both sides, with the exeeption of middle rib, glabrous; stipules ovate- or lanceolate-subulate, long persistent, at length reflexed, often of the length of the leaves; pedicels short, axillary, solitary, with rounded or oyate ciliate bracteoles; upper lip of the somewhat silky calyx bifid, lower lip three-parted; pod much compressed, roundish-rhomboid, covered with rusty downs, containing from one to three brown black-spotted seeds. In the Australian Alps from the Mitta Mitta to the tribu- taries of the Snowy River, as well between rocks as along the peaty margins of the rivulets. This singular and beautiful plant descends never to regions lower than four thousand feet; and being at five thousand for many months during the year covered with snow, it will, like the new previously mentioned Burtonia and many other of our alpine plants, form an exquisite addition to the garden flora of colder countries. 40 Australian Plants. 20. Psoralea parva. Sparingly pilose; stems herbaceous, procumbent, almost simple; leaves trifoliolate, on long petioles; leaflets narrow- lanceolate or of the radical leaves elliptical, perfectly entire, dotted, ending in a sharp point, the intermediate one larger; stipules streaked, ovate-lanceolate, with a subulate apex, peduncles long; spike at first capitate, but generally at length interruptedly extended; bracteoles roundish-cordate; calyces somewhat silky, nearly sessile; pods slightly hairy. In dry pastures on the Thompson and Latrobe Rivers, and in South Australia, on the Torrens and Gawler Rivers, on the Barossa Ranges, near Villunga, &c. It differs from Ps. tenax in always trifoliolate smaller and less acute leaves, in sessile less deeply divided calyces, in the form of the longer persistent bracteoles, in the whitish or pink corolla, and in the pod, which is neither black nor smooth. 21. Psoralea adscendens. Smooth or sparingly pilose; stems herbaceous, diffuse adscending, at the base procumbent; leaves trifoliolate, on long petioles; leaflets lanceolate, acuminate, entire, sharp pointed, dotted, the intermediate one larger; stipules lanceo- late-subulate; peduncles long, upwards as well as the calyces somewhat hairy; racemes dense, almost spicate, many-flowered, of the length of the leaflets; bracteoles lanceolate -ovate, acuminate; pods black, wrinkled-scabrous. On the grassy moist banks of the Snowy River, Gibbo River, Mitta Mitta, Ovens River, and along the torrents of the Australian Alps. This fine plant approaches nearer to Ps. Australasica than to Ps. tenax; the colour of the flowers is purple like that of the former, not deep blue as in the latter, from which it differs besides in the greater size of all parts and the above notes. It may be considered a subalpine plant, whilst Ps- tenax hardly advances any where into the mountains. 22. Leptocyamus sericeus. All over grey—silky; stems procumbent; leaflets lanceolate- linear, acuminate, above at length a little glabrescent; pedicels axillary, subsolitary; pods silky; seeds shining- black, even. Australian Plants. 4] On sandridges along the Murray River towards the junction of the Murrumbidgee. To the same genus belongs Zichya Latrobeana of Meisner, Gin Lehmann plant. Preiss. I, p. 94.) CUNONIACEAR. 23. Bauera sessiliflora. Hirsute; leaves lanceolate or subovate, generally entire; flowers axillary and terminal, sessile, pseudo-verticillate; calyces to the middle eight-cleft, with subulate-lanceolate or linear segments and with a slightly ribbed obconico- cylindrical tube; petals purple; stamens about twelve; anthers oblong-ovate, emarginate, black. On the rocky subalpine summit of Mount William, and thence descending along the rivulets into the-valleys. Flowers larger and of a much deeper colour than in Bauera Billardieri. CELASTRINEZ. 24. Celastrus Australis. (Harvey & Mueller.) Climbing; branches warted; leaves glabrous, lanceolate, acuminate, crenate or repand-serrated, their teeth mucronu- late; panicles terminal; capsules three-valved, with one- or two-seeded cells. On the Snowy and Buchan Rivers, not only in rich humid ground, but also on rocks. The first Australian species described of the genus, resem- bling C. paniculatus and C. dependens from East India. LYTHRACE. 25. Ammannia Australasica. Annual, glabrous; stem erect, simple or branched, square; leaves ovate- or linear-oblong, blunt, with a dilated base clasping; cymes axillary, on very short peduncles, or rarely the flowers solitary in the axils; calyces cupshaped, with four very short acute teeth and four indistinct ones alternating with them; petals four, nearly lanceolate, flavescent, very soon falling off; stamens four; capsule globose, extremely thin, one-celled. 42 Australian Plants. On boggy places, periodically under water, along the Rivers Murray, Darling and Murrumbidgee. The first species discovered in Australia, bearing affinity to A. multiflora from East India, and to A. pusilla from South Africa; differing from both already in the colour of the petals. ARALIACE. 26. Panax augustifolius. Fruticose, unarmed, glabrous; leaves simply or bi-pinnate; leaflets spreading, carnulent, in three to seven pairs, oblong —linear, perfectly entire or sometimes again dissected, almost veinless, opaque, above dark-green, beneath pale; umbels distant in the panicle, pedunculate, many-flowered; calyx obsoletely toothed; styles two, reflexed at the extremity. Dispersed through the Mountains from Dandenong and Mount Macedon to the Buffalo Ranges, and through a great part of Gipp’s Land. The berries are blueish-white, like those of the following species, but somewhat smaller. 27. Panax dendroides. Arborescent, unarmed, smooth; leaves simply or bi-pinnate; leaflets in five-seven pairs, lanceolate, acute, entire, opaque, beneath paler, with above prominent veins; umbels many- flowered, forming a divaricate panicle, which is of equal length with the leaves; calyx with five short teeth; styles two, reflexed from the base. Not rare in the valleys of the southern and eastern ranges of this colony. CAPRIFOLIACES. 28. Sambucus xanthocarpa. Arboreous; leaves pinnately three- or five-foliolate or bi- pinnate, smooth, without stipules; leaflets lanceolate or ovate- lanceolate, long-acuminate, with exception of the basis sharp- serrated, cymes with five or seven principal branches; flowers three- or rarely four-parted; berries yellow, three-seeded. On the shady moist banks of the Brodribb, Snowy and Cabbage Tree Rivers. A tree with the habit of the common Elder and perhaps of equal utility. Australian Plants. 43 Composit. 29. Brachycome leptocarpa. Annual; leaves linear-cuneate, as well as the branches covered with articulate hair, at the upper end cut or pinnati- fid, their teeth or segments acute; peduncles naked, filiform, upwards smooth; scales of the involucre blunt, glabrous; akenia cuneate-linear, compressed, pale-brown, with naked margin, on both sides hairy-scabrous; pappus conspicuous. In low grassland, not unfrequent in the colony of Victoria, as well as in South Australia. Similiar to B. debilis. 30. Brachycome ptychocarpa. Annual, glabrous-scapes filiform, generally naked; leaves pinnatisected, with linear acute segments; scales of the involucre blunt, ciliolate; akenia very small, brown, sur- rounded by a ciliolate wing, on both sides with three hairy- scabrous ribs, the middle rib more prominent; pappus minute. In the Buffalo Mountains. Like the following a small tender herb. 31. Brachycome nivalis. Perennial, herbaceous, smooth; leaves all radical, some- what carnose, pinnatisected, or rarely entire, on long petioles; their segments distant, linear, entire or pinnatipartite, acute; rachis linear; stems simple, much longer thun the leaves, naked or with a solitary bractea; scales of the involucre lanceolate - oblong, with ciliate torn margin; receptacle hemispherical; akenia compressed, oblong- cuneate, with a conspicuous pappus; those of the disk very narrowly winged; those of the ray surrounded with a broad torn mem- brane, on both sides shghtly convex, rough towards the summit. On the highest summits of the Australian Alps, in grassy or peaty soil; for instance, on Mount Buller and the Cobboras mountains. A remarkable species, often tinged with a purple hue. 32. Brachycome multicaulis. Suffruticose, somewhat scabrous; stems numerous, ascend- ing, foliate, simple or a little branched, naked towards the summit; leaves nearly sessile, pinnatifid; their segments 44 Australian Plants. linear, acute, close to each other, short in the upper leaves; scales of the involucre cuneate-oblong, somewhat scabrous, blunt, with membranaceous ciliate-torn margin; receptacle convex ; akenia compressed, oblong-cuneate, with a very short pappus; those of the disk with very narrow hardly ciliolate wings; those of the ray with broader somewhat cal- lose margin, rough towards the summit. On the highest cliffs of Mount Buller. 33. Brachycome chrysoglossa.. Perennial, glandulously pubescent; leaves only on the lower part of the stem, oblong-cuneate, at the top rounded or truncate with a few notches; scales of the involucre blunt, obovate, with a broad membranaceous torn-ciliate margin, glandulous on the back; ray golden-coloured; akenium tawny yellow, margined, compressed, surrounded by a broad irregu- larly pectinate-ciliate wing, thickened and somewhat scabrous on the disk; pappus conspicuous. In the Mallee scrub towards the north-western boundaries of the colony. Remarkable for the colour of its flower-ray, otherwise closely approaching in affinity to B. calocarpa. 34. Calotis anthemoides. (Sect. Acantharia.) Smooth; root fibrous, producing runners; stems simple; radical leaves on long petioles, pinnately divided, the lower segments linear, entire, the rest pmnately cut into linear acute divisions; leaves of the stem small, remote, sessile, lanceolate, entire or rarely toothed; scales of the involucre few, disposed in two rows, ciliate, but smooth on the back, outer ones almost round; akenia cuneate, nearly compressed, margined and broadly winged, with exception of the tops even and smooth; awns generally eight, valid, retro-hispid, alternately very short, and of the length of the akenium. In muddy localities in the neighbourhood of Station Peak. A singular plant, differing from the rest of the species, as well in habit as in the hermaphrodite flowers of the disk. Ray whitish. 35. Angianthus brachypappus. Glomerules tapering gradually into the base, at last Australian Plants. 45 brownish; pappus ciliate-torn, shorter than the akenium, or producing a single hair, which is not plumose at the summit, and shorter than the corolla. On barren plains near Swanhill. Although the above notes appear to offer the only distine- tive marks between this and Ang. tomentosus, the only hitherto know species, yet this new one may be most easily recognised by them. 36. Heckeria ozothamnoides. Branches scantily woolly ; leaves linear, mucronate, with revolute margin, beneath grey-tomentose ; heads 5-7- flowered; all scales of the involucre upwards pale-yellow. In dry places on Barker’s Creek, on the Upper Murray and Snowy River. The species upon which I founded the genus originally may be briefly thus characterized. Hecheria cassinieformis. Leaves semiterete, blunt, as well as the branches scabrous ; heads 2-3-flowered; interior scales of the involucre upwards white. 37. Antennaria, Gaertner. (Sect. Actina.) Scales of the involucre radiating. Heads of the fertile plants with several rows of female flowers in circumference, and with hermaphrodite ones in the centre. Heads of the sterile plants with only hermaphrodite flowers, a few rarely fertile. Pappus at the extremity clavellate, with exception of that of the female flowers, which is not thickened. Antennaria nubigena, Stems herbaceous, creeping, corymbose, short, upright, cespitose; leaves dense, flat, oblong or ovate-cuneate, some- what acute, entire, spreading, clasping at the base, one-nerved, on both sides covered with a thin appressed silver-grey toment; flowerheads terminal, generally solitary, sessile; inyolucres hemispherico - campanulate; its scales smooth, acute, entire, the middle ones lanceolate - oblong, white at the top; akenia tereti-oblong, scabrous. 46 Australian Plants. On the rocky summits of the Cobboras mountains, covered nearly throughout the year with snow. A truly alpine species like most others of this interesting genus, formerly not found represented in Australia, unless erroneously referred by Candolle to Gnaphalium (as G. Catipes. ) 38. Senecio vagus. Glabrous; stem suffruticose, with spreading branches; in- ferior leaves large, pinnati-sected, with generally two pairs of segments, which are long-lanceolate, acute, remotely and grossly toothed; the terminal segment very large, trifid and toothed or laciniated; upper leaves lanceolate, entire or trifid, tapering into a short petiole; flowerheads panicled, with a conspicuous peduncle, and large lanceolate-linear bracteas ; scales of the almost bell-shaped involucre ten to twelve, equal in length to the disk, acute, on the margin scarious, on the back with black papills; ray spreading; akenia glabrous, angulate, furrowed, transversely rough, half as long as the pappus. In shady moist valleys of the Dandenong ranges, of Mount Disappointment, and on the Delatite. A smaller variety (alpestris) with thicker more dissected leaves occurs on the rocky summit of Mount Buller. STYLIDER. 39. Coleostylis Sonderi. All over glandulously pilose; stem simple or branched at the top, foliate; leaves alternate, roundish—heartshaped or rhomboid, the uppermost sessile, the rest petiolate ; pedicles axillary, solitary, forming a terminal corymb; basis of the corolla tubulose. On wet places near the Violet Creek found by Mr. C. Wilhelmi. A neat little plant of the habit of C. Preissii. GENTIANE®. 40. Sebea albidiflora. (Sect. Phyllocalys.) Leaves somewhat fleshy, broad -ovate, the lower ones roundish, blunt, almost nerveless; sepals indistinctly keeled, Australian Plants. 47 oblong, blunt, winged at the base; cyme simple, close; lobes of the corolla four, whitish, ovate-oblong, blunt, half as long as the tube; style short-exerted, with a bifid stigma. In saline pastures from Port Phillip to Port Fairy, and at George Town in Tasmania. Approaches next in its characters to S. albens from South Africa. Myorporina. Pholidia, R. Brown. (Sect. Sentis.) Leavesalternate. Calyx four-parted. Drupe bony, hard- beaked, with imperfectly divided cells. Al. Pholidia divaricata. Twigs spreading, spinescent, glabrous or with a row of white short hair; axils of the leaves somewhat bearded; leaves glabrous, linear - oblong, blunt, gradually tapering into the base, entire; flowers axillary, solitary, nearly sessile; segments of the calyx narrow-lanceolate, long-acuminate, ciliated ; corolla outside starry-velutinous ; its upperlip with two very short lobes, lower one three-parted. In bushy plains, subject to inundations on the banks of the Murray River, the Darling and Murrumbidgee. An ornamental shrub, several feet high, with purple or white generally spotted flowers. (Sect. Hremicola.) Leaves alternate, deciduous. Calyx five parted. Drupe dry, acuminate, with almost entirely divided cells. 42. Pholidia polyclada. Glabrous; branches and twigs spreading, not spinescent; leaves linear, somewhat channelled, blunt, entire, sessile; pedicels axillary, solitary, upwards thickened, longer than the calyx; axils glabrous; segments of the calyx nearly cordate, acuminate, with minute ear-like appendages at the base, indistinctly ciliate at the margin; corolla outwards glabrous, very wide, surpassing many times the length of the calyx; upper lip bifid, lower one three-parted. In sandy-loamy desert plains at the junction of the Darling and Murray. 48 Australian Plants. A shrub with intricate branches, about six feet high. Flowers large white. This species forms an intermediate link between Eremo- phila and Pholidia. To the same genus I refer also Myoporum brevifolium of Bartling. LABIATAE. 43. Prostanthera spinosa. Branches numerous, spreading, hispid; twigs short, spines- cent, foliate at the base; leaves lanceolate or roundish-ovate, acute, entire or repand, glabrous or below imperfectly hairy; peduncles thin, axillary, solitary, surpassing twice the length of the calyx, at the middle bibracteate; calyx sparingly his- pid, its lips entire, the lower one hardly longer; corolla of filac-colour, outward but little hairy; longer spur of the an- thers exceeding nearly twice the cell; the other abbreviate. On springs and irrigated rocks in the Grampians. This species is remarkable for its prickly branchlets. A4, Prostanthera coccinea. Branches hirtellous; leaves. small, somewhat thick, with reflexed apex, linear-oblong or simply linear, blunt, flat or on the margin slightly recurved, hairy-scabrous, at length glabrescent, in the axils fasiculate; flowers near the top of the twigs axillary; peduncles a little shorter than the calyx, which is with exception of the ciliolate margin glabrous; its lips entire, the lower one a little longer; corolla red, three times longer than the calyx, somewhat hairy, its upper lip longest; spurs of the anthers adnate, the longer one hardly as long as the cell. In the Mallee Scrub on the Murray, on St. Vincent’s and Spencer’s Gulf. A low diffuse bush, allied to P. microphylla (All. Cunn., in Benth. lab. p. 454). 45. Prostanthera eurybioides. Branches puberulous; leaves thick, very small, clabrous, linear - oblong, entire, slightly concave; the younger ones fasiculate, those surrounding the flowers broad ovate; flowers axillary, solitary, on short peduncles; the lower lip of the glabrous calyx nearly retuse, little exceeding the rounded upper lip; longer spur of the anthers surpassing the length of the cell. Australian Plants. 49 in the Mallee Scrub towards the mouth of the Murray River. BResembles in habit Eurybia lepidophylla. 46. Westringia senifolia. Erect ; stems densely hirsute; leaves about six in a whorl, crowded, spreading, lanceolate-linear, acute, sessile, with revolute margins, above glabrescent and scabrous, beneath as well as the calyces hirsute; flowers white, axillary, nearly sessile, forming on the top of the twigs a foliate spike ; cayees to the middle divided, hardly as long as the leaves; its seg- ments lanceolate-subulate. On rocks in the Buffalo Ranges and on the ‘summit of Mount Buller. 47. Westringia violacea. Leaves three in a whorl or rarely opposite, linear-lan- ceolate, awnless, with slightly recurved margins, glabrous on both surfaces or beneath along the rib hairy, above dotted- scabrous ;_ pedicles, calyces and twigs appressed - hairy; bracteoles linear-subulate, four or five times shorter than the ealyx; teeth of the calyx lanceolate, acuminate, hardly longer than its tube; corolla violaceous, puberulous. 48. Westringta grevillina. Leaves three in a whorl, coriaceous, broad-linear, spread- ing, acute, with revolute margin, above smooth, beneath as well as ealyees and branchlets more or less grey velvet-hairy; “oom of the calyx mueh shorter than its tube; corolla velvet- airy. On the rocky coast of the Port Lincoln District. CG. Wilhelmi. Nearest in its affinity to W. cinerea. SCROPHULARINZ. 49. Veronica Hillebrandi. Stems short, erect or ascending, all over covered with short reclined hair; leaves thick, on short petioles, somewhat rough, oblong or hastate-ovate, grossly and remotely serrated, truncate or rarely tapering at the base; racemes corymbose, axillary, few-fowered; bracteas ovate-lanceolate; = 50 Personal Observations in the segments of the calyx lanceolate-oblong; corolla large, white; capsules broad -obcordate, slightly compressed, - glabrous; seeds compressed-ovate, brown, wrinkled. On barren ridges along the Coorong, and on limestone rocks around Lake Alexandrina. LENTIBULARINE. 50. Polypompholyx exigua. Urticles ovate; leaves narrow -lanceolate or oblong, tapering into the petiole; scape filiform, one-three-flowered ; corolla rose-red; lower lip nearly horizontal, trifid, at least three times longer than the upper lip, its segments oblong - linear, blunt, the middle one larger, the lateral ones hardly longer than the spur; upper lip nearly erect, bipartit, with linear subulate divisions; palate yellow, with an orange margin. _In mossy, peaty or boggy places at the Grampians, Serra and Victoria ranges, and in South Australia at Kchunga. It differs from Polypompholya tenella, besides in the cha- racters pointed out already, in its larger flowers. Art. V.—FPersonal Observations made in an Excursion to- wards the Central Parts of Victoria, including Mount Macedon, Mclvor, and Black Ranges. By Wi.Liam BLANDOWSKI, Esq. THe Victorian Government having conferred on me the honour of assisting in the formation of a museum of Natural History, and of reporting upon the physical character of those parts which, in the execution of that mission, I should happen to visit, I accordingly selected for the scenes of my early labours that portion of the country including within its area, Mount Macedon (40 miles north of Melbourne), McIvor (30 miles north of Mount Macedon), and the Black Ranges, on the upper Goulburn River, 40 miles eastward of Melvor. I have now the honour to lay before the Philosophical Society, the principal results of my observations during the three months devoted to this interesting object, having reduced them under the following distinct heads:— I. The physical character of the midland portions of the country ; with a review of the general capabilities of, its surface. Central Parts of Victoria. 5E- -II. The Geology, Mineralogy, Paleontology and Y of those IIL. Zoology districts. IV. The Aborigines; their manners, habits, and customs. . I. The general character of the country in the neighbour- hood. of Melbourne, and between that city and Mount Mace- don, is flat and open, comprising a series of extensive plains. They are intersected in every direction by the Yarra and Saltwater rivers, Jackson’s and the Deep Creeks, whose beds, running through in steep gullies, are remarkable for their great depth, averaging about 150 feet. The banks of these streamsare adorned more or less by avenues of thick she-oak ( Casuarina quadravalvis) and he-oak (C. leptoclada). A belt of clay slate, commencing about half way between Melbourne and the Mount, forms a semicircle around the latter on the south : and eastern sides. The soil of those districts which are comprised in that cireuit is much inferior to that of localities favoured by the more fruitful basalt formation, which is very extensively developed around Mount Macedon, its rich agricultural qualities rendering that district particularly» encouraging to the farmer. The only circumstance at all detrimental, is the great elevation of the land above the sea level, which exposes it to the influence of the cold; ice some- times forming, of the thickness of half an inch. The ranges known as Mount Macedon itself, are covered with an exceedingly rich soil, except perhaps one portion. which makes a semicircular sweep towards Alexander’s Head, consisting for the most part of quartzy slate, and enclosing the granite of the south and eastern portions of the chain. Mount Macedon is a lofty and picturesque peak, its sides clothed with forests of gigantic eucalypti; the gullies and ravines which everywhere intersect it, being alike overrun with immense fern trees (Dicksonia antarctice), so dense as to pre- sent an almost impassable barrier to the progress of animals. About two miles from the mount, at the head of Five Mile Creek, is a remarkable hill called Diogenes’ Mount, commonly known to the colonists as “ Dryden’s Monument,” a name singu- larly inappropriate, being the cognomen of a settler in the neighbouring district. For a description of this highly interest- ing mount, I refer to a subsequent page, where full details con- cerning it will be found. _ The dividing ranges between the Deep Creek and the Campaspe River consist of granite, covered with a sandy and unproductive soil. They rise to a considerable elevation, and. 52 Personal Observations in thé on their surface are many remarkable groups of granite boulders ; the soil between these, resulting from the decompo- sition of the basalt, being of an exceedingly rich quality. The two localities last mentioned, viz. the dividing ranges and Dryden’s Monument, for the interest of their geological con- formation and the extreme beauty of their scenery, are almost unequalled throughout Victoria; and offer to the inhabitants of the city, a quiet and instructive retreat for the employ- ment of their leisure hours. Crossing these ranges the traveller merges into the Murray district. Once arrived on the plains, a milder climate than that of the more southern portions of the country, is dis-- tinctly experienced. These elevated plains belong more or less to the basalt formation, and from the fertility of the soil, especially in particular places, (as in the neighbourhood of Dr. Baynton’s station,) as well as good water, a fine climate, gently undulating ground, and most beautiful scenery, are highly deserving the attention of the future settler. North of the Mie Mie Inn, famous as being the spot where the celebrated gold escort robbery took place, the soil is cold : and unproductive; but towards Patterson’s station expands into’ open and fertile plains, entirely free from stones and boulders. - Arrived at the MclIvor diggings, the only particular object of interest, is the track marked out by Sir T. Mitchell, in the: first exploring expedition ever undertaken through Austra- lia Felix. The surface of the country north of McIvor, is both clayey and rocky; is densely timbered and abounds with precipitous: ravines, being thus available only for pastoral pursuits. Between Lancefield and Kilmore the road leads over an. elevated plateau formed of basalt strata. The face of the country is here extremely rocky, and unfit for cultivation ; but in the neighbourhood of the latter township its character changes, and rich alluvial land gratifies the eye of the obser-' ver. Kilmore is fast becoming the centralizing point of an important agricultural district, and is already the largest in-— land town in the whole colony. Eastward of the line of road leading from Kilmore to Sey-. mour, is seen the singular peak known to the colonists as Ferguson’s “sugar loaf” which possesses a considerable de- gree of interest on account of its remarkable conformation and appearance. ‘The rich character of the land around this peak is well known to the settlers, but owing to its elevated position, it is, like the plateaux of Mount Macedon, much ex- posed to the injurious influence of the cold. Central Parts of Victoria. 53 On arriving at Seymour (lat. 37° ) the bald granite hills of the black ranges become visible on the eastern horizon. The latitude is the characteristic weather line of our meteorolo- gical phenomena, which is especially manifest in the advanced state of vegetation north of that parallel. This, I imagine, is chiefly owing to the influence exerted by the different ad- joining ranges, viz. Mounts Benson and Gambier, the Gram- pians, the Pyrenees, Victoria, Alexander and Kilmore ranges, which all lie under the same latitude, and present an effectual barrier to the cold south wind, thus rendering the vegetation to the north of them fully four weeks in advance. ; Approaching Seymour I was delighted to behold the mag- nificent river, the Goulburn, upon whose banks it is situate 5 its sides adorned with rows of shady wattle (Acacia molis- sima) and lofty gum trees. I am convinced that by the removal of but few obstructions, steam communication could _be easily effected between that river and the Murray Settle- ments. ; The highest point of the Black Ranges is formed of granite. The view from certain points of this hill is grand and im- posing; at its foot is seen the Goulburn hastening into the Murray, after traversing a vast tract of dark forest land extending as far as the eye can reach, and clothing with the deep and sombre hue of the eucalyptus the sides of the lofty Alps, whose glistening summits are crowned with snow. ‘The southern slopes of the Black Ranges are exceedingly steep, so much so, that finding it impossible to proceed with a dray in that direction, I was compelled to retrace my steps and pursue a different route. The right bank of the Goulburn, on that side opposite to the Black Ranges, is both rugged and mountainous ; it is densely covered with thick forest, and will for centuries be of use only as pasture ground. Now and then, however a rich gully occurs; but these are exposed to counterbalancing drawbacks, being subject in winter to sudden and heavy floods, scooping out ravines in the alluvial soil, of con- siderable extent and depth. In May and June, the months in which the cold sets in, the higher ranges become, during the night, covered with snow, which however disappears with the warmth of the morning sun. The scenery of these mountains reminds one of the rugged passes of Switzerland or the Rhine, and the hospitality which characterizes the _inhabitants of mountainous districts in every part of the _world, is fully borne out by the settlers of the Goulburn, 54 Personal Observations in the who are proverbially the best riders in the country, and sur- pass anything we read of concerning the horsemanship of other countries; this superiority being attributable only to the rugged nature of the district in which they reside. II. Melbourne, as is well known, rests on strongly com- pressed silurian strata, entirely surrounded by the basalt formation. Extremely minute fossils (Aérypa) are found in these strata; but those typolites obtained near Flemington, scarcely two miles from Melbourne, and of which I have pro- cured living specimens from Western Port Bay, are large and perfect. The latter are petrified in brown iron ore belong- ing to the uppermost tertiary formation. - The extensive plains between Melbourne and Mount “Macedon, as has been stated in the former part of this paper, belong almost entirely to the basalt, or, as some Eng- ‘lish geologists term it, the trap formation. The rocks of this class are composed principally of felspar and augite, the latter predominating; and a soil of very superior capabilities arises from their decomposition. The trap rocks which occur throughout Victoria, I have ‘arranged under two distinct heads, viz., basalt proper, and dolerite; the former a black homogeneous mass, sometimes ‘impregnated with different zeolites and iron ore. That ' both are the result of volcanic action there cannot be the “slightest doubt, as they exhibit the most unmistakable signs of having been once in a molten state. _ The different varieties of basalt which occur in the plains above mentioned are :— * 1, Common basalt or bluestone; in columnar platforms and irregular boulders. . Porous basalt in irregular forms; on account of its porosity unfit for building purposes. - 3. Pumice stone, like basalt. Swims in water; attracts and retains the heat very powerfully. » 4, A lithodomous mass of an ochre-brown colour ; easily crumbled. It is questionable whether it be not of aqueous origin, its formation taking place when the volcanic power was finally subdued. 5. Black soil of a crumbling nature. The decomposition of this species produces a soil highly valued for agri- cultural purposes. When mixed with clay the ground becoming what is termed by the colonists “ honey- combed;” and if stones be intermingled with it, mounds are raised, designated “ dead men’s graves.” tS Central Parts of Victoria. 55 Eastward from Alexander’s Head, on the Deep Creek, is a gully containing groups of basaltic columns of considerable interest. They are from fifteen to twenty feet in height, and about one foot apart; the bases very convex, but ‘at the summits concave. Below these columns is a stratum of porous basalt a few feet in thickness; and beneath this another extremely porous, and perforated with large irregular holes, whose edges are rounded by the action of internal fire. The whole rests on a stratum of basalt conglomerate.. The low ranges east of Mount Macedon are composed of quartz, and though similar in character to the Cambrian formation, are apparently devoid of fossil remains. “Near Fawkner’s old station is a bald hill formed of dole- rite boulders, from 2 to 10 feet in diameter and about the same height, cropping out from the smooth surface, and in- ‘investing the hill with a rugged appearance. The fine grained granite which forms the summits of the ‘Mount Macedon chain, exhibits a strong inclination to shelve off in horizontal layers. ‘The felspar which enters into the composition of this granite bears a very large proportion to the quartz, the black mica is distinct and characteristic. I could nowhere detect any indications of precious stones on these ranges, which are very scantily covered with a thin ‘coating of alluvial soil. ; ~ Some distance N.E. from the peak of Alexander’s Head, is the spot where the discovery of bones of gigantic antediluvian fossil birds took place, 5 or 6 years since, in a basaltic cavern. I was much disappointed at my ineffectual endeavours to ob- ‘tain similar specimens, in consequence of my inability to sup- _press the springs of water sufficiently to enable me to reach the proper depth. Two species of granite occur on the dividing ranges be- tween the tributaries of the Deep Creek and the Murray River. The first is composed of coarse crystallized felspar, oligoclass and albite, with a little mica and quartz. This ‘granite is found in shapes somewhat similar to ladies’ thim- bles; varying from two to one hundred feet in height, and . from ten to three hundred feet in circumference. The fan- ‘tastic arrangement of these groups is calculated to afford a constant theme of speculation as to the original cause which produced it, amongst those whose fancies lead them to the consideration of such things. On Perry’s run I saw a boulder of an enormous size resting on a base of scarcely twenty square feet. So remarkable an occurrence deserves to be re- 56 Personal Observations in the corded amongst those geological wonders which in different * countries have so frequently exeited the curiosity of even the most thoughtless of mankind. There is also a very interesting ' group of boulders on Dr. Baynton’s run. The second species of granite on the dividing ranges, con- sists of fine crystallized felspar, with a small admixture of mica and quartz, the latter in minute particles. This granite constitutes the higher ranges on Mollison’s run, and appears similar to that at Mount Macedon; it exhibits a strong ten- dency to split perpendicularly. ; . The ceinted spot which supplies the natives with stone (phonolite) for their tomahawks, and of which I had been informed by the tribes 400 miles distant, I was unable, at this period of my journey to trace out ; but subsequently was fortunate enough to hit upon it accidentally while in sie of other objects, with the assistance of F. Mackenzie, sq. , Three miles east of Lancefield is a lofty chain of hills, - running nearly north and south; the highest summit of which is called Mount William. These ranges are intersected by the road leading from Lancefield to Kilmore, and which divides the basaltic strata, on the north from the clay slate rocks and slate of the southern portion of the range. The basalt gradually changes its specific character, northward, till at Mount Wil- liam it becomes distinct phonolite, of a hard and glassy tex- ture. A most excellent stone for macadamizing roads occurs in this locality, and will be a treasure to the neighbouring ‘district, when the progress of the country shall demand its application. Good brown iron ore also occasionally occurs, though not in great quantities. Having observed on the tops of these hills a multitude of fragments of stones which appeared to have been broken artificially, and which I recognised as phonolite or clink- stone, I was led to trace them to the source from which they appeared to have proceeded, a spot three-quarters of a mile eastward, on somewhat lower ranges. Here I unex- pectedly found the deserted quarries (kinohahm) of the aboriginals, which I had previously been unable to discover. = The phonolite (tadijem), as before mentioned, is that of which their tomahawks are formed. The quarries which extend over an area of upwards of 100 acres, present an appearance somewhat similar to that of a deserted gold field, and convey a faithful idea of the great determination displayed by the ab originals, prior to the intrusion of the white races. They _ Central Parts of Victoria. 57 are situated midway between the territories of two friendly tribes,—the Mount Macedon and Goulburn, — who are too weak’ to resist the invasion of the more powerful tribes; many of whom, I was informed, travel hither several hun- dreds of miles in quest of this invaluable rock. The hostile intruders, however, acknowledge and respect the rights of the owners, and always meet them in peace. The phonolite is of great hardness, and is distinguished from basalt by its greater specific gravity, its chemical com- position being—silica, 67 ; alumina, 18; natrium,7; calcium, 7. The surface of the stratum is very rugged, and of a greenish colour. It is rather difficult of fracture; otherwise it is well adapted for metalling roads. The basalt formation extends about four miles westwards ‘of Lancefield, but is then interrupted by slate and milky _quartz, strongly indicative of auriferous strata. Still further westward these are succeeded by dolerite, which extends over Alexander's Head, Mount Macedon, and Dryden’s Monument. Dryden’s Monument is, as well on account of its geological character as its singular conformation, one of the most ‘remarkable spots in Victoria, if not in whole Australia, and were a careful and minute description of it made, accompanied with good drawings, it would not fail to engage the attention of every geologist. The approach to it presents a scene of the most imposing grandeur. A massive wall of dolerite, whose deep and sombre hue is in exquisite harmony with the dark green of the eucalyptus, rises almost perpendicularly above the loftiest of the trees, and imparts a striking majesty to the whole view. The interest increases at every step approaching the monument, and a beautiful variety of rapidly changing scenery is unfolded like a panorama before the observer’s eye. At the base about a thousand pyramidal columns, from fifteen to thirty feet in diameter, and thirty to one hundred feet in height, rise in: bold relief from the sur- face, and invest the hill, which is about a mile in circum- ference, with an appearance not dissimilar to that of a gigantic porcupine, or to a colossal representation of the structure formed by the termes bellicosus. That this hill was formed by subterraneous agency, acting at two separate periods, there can be little doubt. At the first era of its formation a naked semicircular hill was raised; and before sufficient time had elapsed to allow the surface to cool and harden, and while it was yet in a plastic state, a 58 Personal Observations in the second eruption took place, resulting in the production of the peculiar columns mentioned in the preceding paragraph. The origin of their formation reminded me of the phenomenon attendant on the refining of silver, asin both cases a discharge of gases must have taken place. The columns are solid, although they contain a considerable number of hollow concretions (septarians), from one to three feet in diameter, which are, however, filled up with érzpoli or steinmark, a finely ‘pulverised earthy deposit, of a greyish yellow colour, and a dry tigeh texture. This tripoli, whose component parts are as follows:—silica, 80 ; alumina, 2; iron, 8; water 5; sulphurous acid, 5—is, I think, mostly derived from the decomposition of silica ; it is very soft, and is much valued in other parts of the world, as a polishing material for hard metals and precious stones. Many of the septarians are fractured or burst, and their internal structure thus exposed to view. I attribute these fractures to have originated from the following cause, viz., from the decomposition of the outer surface of the columns by the usual atmospheric action. The last lamine being at length penetrated, the rains gained access through the fissures, and the expansive power of the tripoli, arising from the “moisture, ultimately burst the septarians; and their contents, issuing from the opening, on to the rocks beneath, dotted them over with white spots, some of which are still obser- ‘vable, though the greater part of them are wholly erased by time. The soil between the columns, which are so numerous and thickly disposed as scarcely to allow a rider to pass- between, arises from the decomposition of the dolerite, and is extremely rich. The physical conformation of Mount Macedon is identical with that of Diogenes’ Mount, although the peculiarities of the former, which I have here endeayoured “to describe, are not so marked, or so fully developed as the latter. "Between Dr. Baynton’s and Mr. Perry’s run, and the Mie ‘Mie Inn, are extensive basaltic plains. Between Mr. Pohlman’s and Mr. Perry’s I found boulders of magnesite, about one ~foot in diameter, and similar in appearance to the stone _which I had previously observed on Brock’s run. The steep banks of the Campaspe consist partly of basalt and of slate, with quartz scattered over the surface. East- ward of the Campaspe, from Dr. Baynton’s to the Mie Mie nn, the country exhibits every indication of being of an ~ guriferous character. Central Parts of Victoria. 59 A few miles south-east of Perry’s home station, I came upon a stratum of a granitic character, about one chain broad ; and, which is particularly worthy of notice, as it is a species of rock entirely new. The stones on the surface of ‘this stratum are all more or less rounded, and quartz cry- stals are remarkable, forming regular dehexahedrons. The whole of Perry’s run eastward of the McIvor gold-fields is of an auriferous character. The stratification, which con- sists of slate alternating with quartzy rock, is almost perpen- dicular, and pursues a gently undulating course, whose general run tends nearly north and south. At Mclvor I observed boulders of dolerite of considerable size, and haying ‘a peculiar depression on their summits, extending across the auriferous strata. From information which I received through the kindness of Mr. Chauncey, I was enabled to obtain chromium, anti- ‘mony, chlorite slate, and a considerable number of petrifac- tions, on the mountainous ranges to the north of Heathcote. The whole of the strata on these ranges (Mount Ida) consist of quartzy rocks containing rhodicrinites. I am of opinion that it is the Cambrian, and not the upper Silurian formation, ‘which is there represented; in support of which I refer to the following passage from Lyell :— “Below the silurian strata in Great Britain is a vast thickness of stratified rocks, for the most part slaty and de- void of fossils. In some places a few organic remains are detected, but they are usually obscure, and whether the species will prove to be sufficiently distinct to entitle the rocks containing them to rank as an independent group, may be doubted. They attain a thickness of several hundred yards, and are chiefly formed of slaty sandstone and conglo- merate, with brachiopoda and a few zoophytes.” i At the Mie Mie Inn, I met with a stratum of slate; and ‘in attempting to ascertain its degree of cleavage, split it with perfect ease into thicknesses of pasteboard, whence its adaptability to the roofing of houses is at once obvious, and needs no comment. I have also seen it in slates of great ‘size split naturally. The Black Ranges consist of a compact globular mass of granite surrounded with slate. Imbedded in this granite is a fine felspathic stone, similar in character to that met with in the dolerite at the McIvor Gold Fields. On certain points of this ridge, covered with sandy alluvial soil, are found specimens of smoky: quartz and black-towr-- maline (schérl) imbedded in hkaoline or decomposed felspar. 60 Personal Observations in the The chemical constitution of the latter is aluminum 35, silica 48, and water 13; it is found in cavities twenty or twenty-five feet in diameter; and could be profitably turned ‘to account in the manufacture of china glass. The smoky quartz is of great beauty, and besides being an ornament to museums, is valuable as an article of trade for jewellers’ pur- poses. Hence it would be a profitable investment for the employment of labour; many valuable specimens could in a short time be procured by three or four workmen under good superintendence, and the principal expended (£200 would cover all) would be profitably returned by the sale of speci- mens. : The black tourmaline or schérl is interesting on account of the peculiar form in which it is crystallised. While on these ranges, as well as on other occasions, the absence of mountain limestone and mica slate in our primitive rocks struck me as a very remarkable fact, in some measure accounting for the scarcity of precious stones in our plutonic rocks. III. Fish.—In the spring months the Goulburn is too deep to afford a plentiful supply of fish, but later in the season they may be obtained in large quantities. As soon as the volume of the rivers begins to diminish, the finny inhabitants leave the mud at the bottom, where they had concealed them- selves for warmth, and disport themselves in the higher tem- perature on the surface of the water. Seven different species of fish are known by me to exist in the Murray; and five other distinct species inhabit our smaller rivers. Of Mollusca only four species haye as yet been found in the rivers and lakes of Victoria, viz., three varieties of uni- valve, and one of bivalve. It is difficult to account for this remarkable and somewhat characteristic fact; but I am in- clined to think that the absence of limestone in our moun- tains and the long summer droughts stand in some connection with it. The Mollusca referred to are— : 1.—Lymnaea palustris (?) of Lamarck. This shell is about one inch in length, and consists of three or four rapidly decreasing volutions, from left to right. It is diffused through "all our lagoons. 2.—Lymnaea peregra (?) of Lamarck. The shell of this spe- cies is about three-eighths of an inch in length; the volute winds from left to right, and the colour is a dark grey. It is very plentiful in the low plains, which in winter are covered with water, but become dried up in the warm season. Central Parts of Victoria. 61 3. — Bullinus obscurus (?) — This shell is about three- eighths of an inch in length, the convolutions winding from left to right ; colour—dark yellow. It is plentiful in the nu- merous brackish lagoons. 4.—Unio tumidus(?)— This shell is very plentiful in all our rivers, and forms a considerable portion of the food of the natives during the summer season. Frogs.—During my stay at the Goulburn in September, three species of frogs came under my observation, all very plentiful along the banks of the river. Snakes and Lizards.—In the earlier part of October snakes and lizards become plentiful; and in the beginning of the ensuing month change their skins. They prey upon young broods of birds and animals at this season. Black duck.—In the middle of July the sheltered places at the base of the Mount Macedon ranges become the resort of swarms of birds of every class. The natatores in particular congregate in vast flocks on the swampy plains. Conspicuous amongst these is the black duck (Anas superciliosa) aud little teal. The wood duck (Bernicla jubata) is also observed in groups of three or four individuals in these immense flocks; and the gay plumage of the mountain duck (Casarca tadarnuides) here and there becomes visible. i Towards the latter end of July, the commencement of the breeding season, these birds separate in couples; they breed in the following month, and the young are brought forth in September. Plover.—At this period (July and August) two varieties of plover, the alarm bird (Lobivanellus lobatus), and black breasted plovit, (Sarciophorus pectoralis), gather in con- siderable force around Mount Macedon, on the plains, especially where the ground is honeycombed. Blue Crane (Ardea Nove Hollandie). — In this month the blue crane may be observed flying singly through the gullies and along the creeks. This well known bird chooses his mate in September, and evinces the most ardent attachment towards her; the female, aware of this, and desiring to raise the jealousy of her paramour, pre-’ tends not to reciprocate his affection, and continually mani- fests a pretended desire to desert him. The black shag or cormorant (Phalacrocorax carboides), frequents the creeks and gullies at this period, and is seldom observed in groups. pee The curlew plovers ( Oedicnemus grallarius), which gather’ 62 Personat Ubservations in the in groups of three or four, disturb the quiet of the night with their loud and shrill voices. The order of Rassores is here represented by several varieties of quail. The predominating species (Coturniz - pectoralis), frequents the high grassy ground near the banks of the creeks. In September pigeons begin to arrive from the northern countries at our more grassy and congenial plains. The absence: of the woodpeckers in Australia is rather remarkable, as they are universally distributed over the whole world, Polynesia excepted. The family psittaci, (order incessores), are not very fre- quently seen during the winter months, if we except two varieties of parrot, the blue mountain ( Trichoglossus Swain- sonit, and Trichoglossus porphyrocephalus), who are observed in the box trees, which, at the season alluded to, are beginning to blossom. Cockatoo.—At the commencement of the sowing season the white cockatoos, (Cacatua galerita), concentrate in large flocks in the agricultural districts, and cause much annoyance to the farmers. The gang gang cockatoo, or red crowned parrots, ( Calloce- phalon galeatum), evince the most extraordinary attachment to each other, and which I have repeatedly had occasion to remark. If one of a group of these birds be shot, the wounded bird, clinging to the tree, cries loudly till dead; and a number of others, in sympathy for the fate of their unfortunate com- panion, refuse to quit the tree, and may be secured one after another. King Parrot.—The beautiful king parrot or red lory, (Aprosmictus scapulatus), is far from being plentiful at Mount Macedon. It frequents the tops of gigantic eucalyptus, and isa very restless bird, continually flying from tree to tree. Cuckoos.—Of the cuckoo I have observed a number of species. These moody birds sit motionless on the lower branches of the eucalyptus, and observe with lethargic indifference the exciting love affairs of the other inhabitants of the forest. Magpie (Gymnorhina organicum).—In September the magpie chooses his mate, but invariably has many aspiring rivals to contend with. _ Magpie Lark.—The magpie lark, (Grallina Australis), takes. advantage of the contests which arise between other birds,. especially the white magpie, at the commencement of the : ( ‘7sa1o QQpIAII YPM prazy ) if ; “SOOLVIIOD'A \ 5 : \ ie VINOIDIA 40 SauIg onpypag bun) bung UME DEIDO UlPOYSIFIQIO) auinoggay-suos 2hounpai/ sg pad wibu 3 UM DLT OOQOYIAD PIID.12U VY SHALIUMLL SHYIUNY.SOVYN7OD GLE ‘ Ban MYT AALHOHUNEY Ns OOYOYODD SIIQOOQVPDOT VA IQOIY RID T PVQRIDD Central Parts of Victoria. 63 coupling season, and dexterously plucks feathers from the. excited combatants, with which to line the interior of his nest. In September the crows (Corvus corondéides) concentrate in large numbers around the squatters’ home stations; where they pick the skins which are there hung out to dry, and feed upon the refuse of the stations. They are very trouble- some to the bullocks, by picking in the hide for insects; and I have often seen one of these animals surrounded by them, and being far too lazy to rise, maintaining a perpe- tual flourish of his tail, in the vain endeavour to drive them off. In July the satin birds (Ptilonorhynchus holosericus) Baer in multitudes in particular localities, especially round eserted sheep stations. These large flocks consist principally of females, being accompanied only by one or two males, living in polygamy. In August and September, however, these birds retire into the more secluded districts. The white-winged chough, or black magpie ( Corcorazx leu- copteris), throughout the whole year associates in groups of ten or fifteen, and frequent the dense and hilly parts of the forests. Its voice is both loud and deep, and, when roused, breaks the silence of the bush by its monotonous cries, and peals forth an alarm to all the birds and animals of the forest. Hence it is looked upon with a distrustful eye by the sportsman ; and I can myself testify to the annoyance which it in this manner causes. Squeaker—The squeaker (Strepera anaphonensis) is a shy and solitary bird, living entirely on the flats, and is remark~ able on account of its frequenting only the same locality. He is hence easily distinguished from the Gymnorhina tibicen, pare shrill and piping voice is so well known on all the high nds. _ Little Kingfisher.—The little kingfisher (Haleyon sanctus) is plentiful along thé banks of the creeks and rivers, but quickly disappears at the approach of the observer. ‘ ~ Laughing Jachass.—The great kingfisher (Dacelo gigantea) or, as it is more familiarly known, the laughing jackass, dur- ing the winter lives entirely on small fish, but in the summer months snakes and lizards form the staple of its food. It is well known to the colonists for its peculiar cry; at the first dawn of sunrise its wildlaugh is heard resounding far and wide through the woods, waking up the birds and animals of 64 P Personal Observations in the the forest. At sunset, again, his loud notes summon all na-" ture to rest, and peal forth a last good night to all. Friar Bird.—The Tropidorhynchus corniculatis is well known to the colonists by the names “poor soldier,” “leather-headed jackass,” “friar bird,’ &c., &c. This_ curious bird, in common with several other varieties of honey-eaters, is remarkable on account of its extreme liveli- ness, and the singular resemblance of its notes to the human voice, which is a source of much amusement to ladies residing in the bush, and who are sometimes inclined to maintain that the bird possesses the power of verbally expressing its emotions. . Flycatchers, &c.—The flycatchers, robins, and finches, are plentiful along the banks of the creeks and rivers, and in the neighbourhood of huts or villages. Of the hawk tribe Australia contains but few distinct families, but the number of species is exceedingly large; about . thirty-seven. . Eagle.—In the mountainous districts, the eagle (Aquilla fucosa), is numerous, and may be observed wheeling ma- jestically through the air, at an immense altitude, scanning the earth with a greedy and rapacious eye, and anticipatory of a luxuriant repast on the carcasses of scabby sheep which strew the plains, and which, indeed, are sufficiently numerous to satisfy the appetite of the whole tribe. Six hundred species of birds have already been discovered in Australia, and about half of these, viz. 300, are inhabi- tants of Victoria. In the National Museum are about 230 species (with an equal number of duplicates), and when we consider that the institution has been scarcely eight months in existence, we have no reason to be ashamed of the progress made when a comparison is drawn with the museums of our sister colonies. . Animals.—Of mammalia Australia possesses but very few. orders ; the marsupial division is however developed to its fullest extent, more so than in any other portion of the globe, being in fact characteristic of this continent. Of the chelopoda we have only one representative, the dingo or wild dog, of which there are three species. Marsupials.—The first of the marsupial order of animals was discovered in America, and the astonishment. which pervaded the ranks of scientific men upon the occasion was still more heightened when it was made known, that in a far Central Paris of Victoria. 65 more distant part of the globe, the marsupiala were developed to their fullest extent. “ Australia,” says Waterhouse, “is the great metropolis of these animals,” upwards of seventy species having been already discovered in that vast territory. This division of the animal kingdom is marked with cha- racteristics, of so peculiar and remarkable a nature as to render them of the highest interest to the zoologist ; I allude to the pouch and to the marsupial bones. The latter perhaps are not so well known to the general public as the more obvious characteristic of the female pouch. Another point of unusual interest in the marsupiala is the manner in which the young are born. Tle embryo, at the time of its birth, is so little advanced when compared with the young of other animals, that many naturalists, in order to explain the diffi- culty of so imperfect a creature reaching the pouch, have started the opinion that it is born through the teat and not through the uterus, in the usual way; but this hypothesis is now almost entirely abandoned, and it is pretty generally received that the young marsupial is conveyed to the pouch by the mother, and carefully placed on the teat, where it remains till it has attained a considerable size. It is a curious and remarkable provision of nature that the young animal obtains the power of vision, so soon as its increasing weight has disengaged it from the teat, although it lives entirely in the pouch a considerable time after the commencement of this, its secondary period of existence. It is not however till the third period that the skin becomes covered with fur, and the animal obtains its full sight; it then quits the pouch, but upon the least approach of danger is received into it. The class reptantia is represented in Australia by the ornithorychus rufus or paradoxus (platypus anatimus of Shaw), and the echidna histryx or porcupine anteater of the colonists. Platypus.—In the first colonisation of Australia both these animals was regarded with so much interest as to elicit the most minute description from every naturalist who visited that vast continent, and rendering later investigations respecting them in some measure superfluous. My observa- tions in this quarter are therefore both few and limited; and though I have had many opportunities for investigations of this nature, I have thought proper to confine myself to those of which less is known. The heel of the platypus is furnished with a large pointed spur, said to be moveable, and which in the male animal is hollow. The object for which nature EF 66 Personal Observations in the provides this appanage is at present unknown, though I am inclined to think that it is intended as a means of defence against attack. Be this as it may, however, the natives entertain a strong prejudice against touching a platypus, though they are not ready to state the reason of their apprehensions. . ; These animals frequent the quiet waterholes of the creeks and rivers, and are easily detected in the water by the circles and eddies which are formed around them. “On the slightest alarm,” says Waterhouse, “they instantly disappear, and Indeed they seldom remain longer on the surface than one or two minutes, but dive head foremosé with an audible splash, re-appearing, if not alarmed, a short distance from the spot at which they dived. Their action is so rapid, and their sense of danger so lively, that the mere act of levelling the gun is sufficient to cause their instant disappearance; and it is, consequently, only by watching them when diving, and levelling the piece in a direction towards the spot at which they seem likely to re-appear, that a fair shot at them can be obtained. A near shot is absolutely requisite ; and when wounded they usually sink immediately, but quickly re-appear on the surface.” The burrows which the platypus makes are very extensive, from twenty to fifty feet in length; its entrance is invariably close to the water's edge, and its other extremity terminates in a capacious chamber, sufficiently large for the residence both of the adults and young. . Porcupine.—This extraordinary animal, which somewhat - resembles a hedgehog, but like the platypus is distinguished by a long and slender bill, like that of a duck, is nowhere observable during the winter months, but makes its appearance ‘on the higher ranges in September. The skin of the porcu- pine is double, the outer one being covered with the fur, while the pines are inserted in the lower skin, which is very muscular and fully half an inch thick. Between this and the flesh is a layer of fat. Like the platypus, the hind foot of the echidna is provided with a powerful horny spur, evi- dently intended by nature as a weapon of defence. ‘The facility and the rapidity with which this animal burrows is truly astonishing, its powerful claws, beak-like snout, and even the spines of its back being brought into requisition. Flinders relates that his dogs having discovered a porcupine anteater were quite unable to produce any impression upon it, and he escaped, “by burrowing in the loose sand—not head foremost, but by sinking himself directly downwards ; a Central Parts of Victoria. 67 and thus presenting nothing but his prickly back to his adversaries.” The body of the animal, when burrowing, is contracted into a minimum spaee, and the loose earth thrown backwards, the whole of its spiny back thus becoming gradually covered, till, by suddenly expanding its quills, it is thrown off. An echidna being placed in a large chest of earth containing plants, the animal arrived at the bottom in less than two minutes, (vide Quoy and Gaimard). I kept two living specimens on a tether rope for a considerable length of time, with the intention of bringing them to Melbourne alive, but unfavorable circumstances compelled me to kill them, and content myself with securing the skins alone. Many naturalists make the platypus and echidna the representatives of a new order. Both these animals possess the ossa marsupiala, though no traces of a pouch are at all discoverable, whence it appears to me that they cannot with propriety be classed with the marsupials. “ The platypus,” says Waterhouse, “is decidedly the lowest of the mammalia yet discovered; and both it and the echidna, in many of their anatomical characters, evince a considerable approach towards the class reptilia. The latter animal, too, is known to possess a power of fasting which had hitherto been ascribed only to reptiles, and becomes dormant when exposed to any considerable degree of cold. Prenziculantia.—Of this order, only one species, viz.:—the Hydromis is at present known to me. Incredible numbers of water rats (Hydromis leucogaster ) frequent the lagoons of the Goulburn during the spring months. These animals are remarkable for their sharp sight, and the mode in which they swim: the whole body, with the exception of the extremities of the nose and tail, being im- mersed. Their extreme vigilance renders them very difficult to be obtained, the least movement being sufficient to cause their instant disappearance; hence it is only by a series of close observations that the beholder is apprised of their great numbers. Wombat.—This clumsy, but well known, animal (Phas- colomys wombat ) during the day conceals himself in his gloomy lair in the loneliest recesses of the mountains, and usually on the banks of a creek, and at night roams about in search of food, which it finds by grubbing about the roots of gigantic eucalypti. Thus protected by the darkness and the dense forest, but few opportunities occur to the naturalist of making close observation of its habits, which accounts for 68 Personal Observations in the the scarcity of information on this subject, in books treating on the Zoology of Australia. Their capture is also attended with a very considerable degree of difficulty, so much so that the utmost exertions of three or four men for several days are insufiicient to effect it. As an illustration of this, I sub- join the following extract from my diary, showing the mode which the natives pursue in endeavoring to effect its capture. Sept. 10, 1854.—The aborigines, Sandy and Mackenzie, searching the banks of the creek for wombats; and succeeding in tracking one to a hole, the opening of which was then carefully obstructed. 11¢h.—Sandy and Mackenzie again repaired to the hole, which, having been cleared of the logs placed before it, was entered by Sandy; the other remaining above, listening at- tentively to the knocking of his companion below, indicative of the situation of the animal. This spot is carefully marked on the surface, and the native having come out, the hole is again blocked. 12th.—The three natives sunk a shaft on the spot, which had been ascertained by them yesterday, and bottomed it at a depth of twenty-two feet. Found, to their astonishment, that the animal had disappeared, and left the work for the day; the opening, as before, being carefully obstructed. 13th.—The natives almost exhausted, so myself and assis- tant began to dig for the wombat, and sunk a new shaft of seventeen feet; but on bottoming it, had the mortification to discover that the animal had again disappeared. Here we lost all traces of him, the natives being equally at fault; and at length gave up the search. The flesh of the wombat is by the natives esteemed as a great delicacy. The taste when roasted is not unlike that of veal; as I have on several occasions, owing to a scarcity of provisions, been obliged to avail myself of it. I could never induce a native to skin a wombat, and after considerable inquiry as to the cause assigned for this refusal, I was enabled to ascertain that it was owing to a supposed pernicious effect which it had upon the bones of the hand. Whether the fat of the animal in a raw state may not exert some influence on the phosporus of the bone, I leave it for others to decide. Koala.—The koala or karbor (Phascolarctos cinereus) frequents very high trees, and sits in places where it is most sheltered by the branches, hence it is with difficulty detected, especially as its fur is of the same colour as the bark of the Central Parts of Victoria. 69 tree on which it sits. This remarkable animal, like the cat, has the power of contracting and expanding the pupil of the eye. Its skin is remarkably thick, and the back is covered with dense woolly fur. It is very difficult to skin, and the natives regard it with the same superstition as the wombat, already mentioned. The male has a gland on the breast which emits a very strong and offensive odour. The kaola uses the two first toes on the fore paws jointly for the thumb; it is a very inactive animal, being known to remain several days on the highest branch of a tree, without any other mo- tion than that of drawing the branches to it, on the leaves of which it feeds. Even when shot it merely shrinks at the report of the gun, but in nowise offers tomove. The natives aver that the koala never drinks water, and from the insuffi- ciency of opposite testimony on this point, it is highly proba- ble that such is the case; as I have myself kept one alive for three weeks without being able to induce it to drink. When thus placed in confinement, it barks in a melancholy tone during the night, like a dog. In September the young koala is in the last period of de- pendency upon its parent, and may be observed sitting on the back of the mother. Halmaturini (Kangaroos ).—During my travels in Victoria I have met with seven distinct species of kangaroo; but in- sufficiency of leisure time has prevented me from making those observations which I otherwise should have desired, and I add only a few remarks concerning those varieties which are the most common. 1. Halmaturus gigantea.—This species, so well known to the colonists by the names of forester, old man, boomer, &c., has now entirely disappeared from the neighbourhood of Mount Macedon, a locality in which it was formerly exceed- ingly plentiful. The Black Ranges, however, on the Goul- burn, are yet inhabited by considerable numbers of these animals. The Wallaby (Macropus nalabatus) is plentiful in the lonely passes of Mount Macedon; but the amazing rapidity with which it retreats into the dense scrub, at the least signal of alarm, renders it of very difficult capture, unless the sportsman be well provided with good dogs trained to the chase. Hypsiprymnus (Kangaroo rat ).—Two species of this ani- mal have come under my notice, viz., the common variety, with the white-pointed tail; and a new species, the tail of which is completely destitute of fur. — 70 ‘Personal Observations in the Dasyurini.—This order is divided into two great branches : the first group contains the bandicoot (Perameler nasutus ) and the bush rat (P. Gunnii ). Both these animals are extremely plentiful throughout the whole colony; in the summer they frequent the plains, whence they are driven by the heavy winter rains, and forced to take refuge in the higher lands. They are not fitted to ascend trees, and being thus confined to the ground and surrounded by enemies, including bush fires, can never become more numerous than they are at present. To the other divisions of dasyurini belong the tiger cat, (dasyurus maculatus, ) and the native cat, (Dasyurusviverri- nus), of which there are two varieties. The Tiger Cat though its dimensions are not sufficiently great to invest it with a formidable appearance, is neverthe- less a most ferocious and blood-thirsty little animal. Of late years, however, it has become very scarce, so that it is with difficulty obtained at the present time. During a stay of two months on and around Mount Macedon I was only enabled to procure one specimen. Native Cat.—Of the Dasyurus viverrinus or native cat there are two varieties, as has been mentioned, viz., the alba niger and alba castarea. These little animals are ex- tremely courageous when attacked; and are very plentiful around sheep stations, where the settlers use every means for exterminating them. There are now large numbers of them in localities where, before the intrusion of the Euro- pean, they were extremely rare; in short, their numbers have augmented in proportion as those of the dingo have diminished, in accordance with that inscrutable law of nature which regulates the equilibrium of animal life. The Rabbit Rat. (—?)—This little animal is well known to hutkeepers and to residents in the bush, on account of its prying and inquisitive propensities, and the fondness which it appears to possess for sugar and other stores. Phalangiste.—The phalangers, 7, e. the balantia of Heiger, contains the two great genera, the flying squirrel (Petauriz ), and opossums (Didelphis ). Of the former, I have observed in Victoria six different species, but on account of insufficiency of leisure time, I am unavoidably prevented from making those observations which I should under other circumstances have desired. The common flying squirrel (Petaurus scuirens) is very plentiful in the large gum trees near the banks of a creek or * Central Parts of Victoria. 71 river, and appears to entertain a peculiar aversion to the high lands. This animal is unquestionably one of the most beautiful animals in the country; and its fur, which is par- ticularly fine and soft, will, no doubt, at some future time, become an article of commercial value. The petaurus flies with considerable facility from tree to tree, on which it is only detected by the motion of its long and bushy tail, and the peculiar shrieks which announce its desperate leaps. The general color is yellowish-grey, sometimes of a rusty hue. Closely allied to the above species is the flying opossum, (Petaurus taquanoides,) black squirrel, which differs from it chiefly in the larger size which it ‘attains, the blackness of its coat, and the greater length of the tail. *A third species is of a white colour, sometimes becoming of a yellowish-grey tint; but whether the specimens which ‘came under my notice were albinos or not I am at present unable to decide. A fourth variety, somewhat smaller than the preceding ; color, ash-grey. A fifth species, still smaller; grey colour. The sixth and last variety is that known by the name of flying mouse (Petaurus pygmeus). The Petaurii, I am inclined to believe, breed nearly two months later than the other branches of the marsupiala. The embryo remains blind during its second period. _ Opossums ( Didelphis ).—The class of animals to which the term opossum was originally applied, and to which it is therefore with strict propriety limited, has no representatives whatever in Australia. The didelphis, however, familiarly recognised as opossum by the colonists, occurs in three different varieties. a. Brush-tailed opossum. b. A second variety, in which the tail is tipped white. c. Ring-Tail Opossum.—The fetus of this species is black, a distinction sufficiently gteat to make it rank as an independent group. The young of the opossums are brought forth in the latter end of June; but do not obtain their full sight till the middle of August. Phalangista.—To the family phalangista belong the flying squirrels ( Petaurii ), and opossums (Didelphis ). Chiroptera.—As yet only two species of chiroptera have been discovered in Victoria, viz., the vampyre bat, and the common small bat. 72 Personal Observations in the Vampyre Bat.—The former, which is’ familiarly known by the name of the “devil,” or flying fox, is found in all the mountain ranges, but is especially numerous in those parts of the coast abounding in hollows and caverns. It sometimes measures three and a half feet across the wings. Common Bat.—The common bat, like the less numerous species above mentioned, is found over the whole colony, but especially in rocky places along the coast. TV.—The Aborigines of the Goulburn are few in number, of a peaceable disposition, and distinguished by a local lan- guage and characteristic habits. The whole of the tribes living in the same latitude towards Mount Gambier, are peaceably disposed, and in this respect. differ most materially from the Fisher and the savage Murray tribes. During my journey to Seymour, 1 met with a camp of Aborigines, by whom I was willingly accompanied to that place. Having observed an unusually large number of dead trees in a forest which we passed through, I was induced to inquire the cause of so peculiar a circumstance, and was informed, in reply, that it was the spot on which a once very numerous Goulburn tribe was overwhelmed by a still more powerful tribe, inhabiting the banks of the Murray. Each of the dead trees represent a member of the extinguished clan; and the custom is still maintained by those tribes neighbouring the Goulburn, and has its origin in the follow- ing superstitious ceremony. Upon a youth arriving at manhood, he is conducted by three of the leaders of his tribe, into the recesses of the woods, where he remains two days and one night. Being furnished with a piece of wood, he knocks out two of the teeth of his upper front jaw; and on returning to the camp carefully consigns them to his mother. The youth then again retires into the forest, and remains absent two nights and one day ; during which, his mother, having selected a young gum tree, inserts the teeth in the bark, in the fork of two of the topmost branches. ‘This tree is made known only to certain persons of the tribe, and is strictly kept from the knowledge of the youth himself. In case the person to whom the tree is thus dedicated dies, the foot of it is stripped of its bark, and it is killed by the application of fire; thus becoming a monument of the deceased. Hence, we need no longer be surprised at so frequently finding groups of dead trees in healthy and verdant forests, and surrounded by luxuriant vegetation. Central Parts of Victoria. 73 The three natives whom I have before-mentioned as having accompanied me to Seymour, having refused to stay with me so close to the lagoon where I had fixed my camp, I inquired the reason assigned for their refusal, and was informed, that an animal somewhat resembling an emu, but with much longer legs, and of so formidable a character as to threaten them with danger, usually makes its appearance during the commencement of the warmer season, and prowls about the lagoons; but whether this statement contained any degree of truth I will not now venture to say. In thescommencement of October the Goulburn river falls to its proper level, the winter rains having then subsided ; and the multitudes of fish which appear in its waters attract hither the tribes inhabiting the surrounding districts. At that season too, they subsist upon eggs, which may then be obtained in abundance; and upon turtle and river mollusca. Hence the reason why they regard with indifference their _ employment by the settlers. At other times of the year, however, when the bounties of nature are not afiorded on so liberal a scale, they avail themselves largely of ants’ eggs, which are collected when travelling through the forest. Tor this purpose the hollow trees, in which it is likely the ants have deposited their eggs, are carefully inspected, and upon the discovery of one containing them it is opened with a tomahawk, and the ants and their eggs abstracted from it. These are promiscuously thrown together into a kangaroo skin and are roughly shaken, by which the eggs, on account of their greater specific gravity, are precipitated to the bottom, and the ants, particles of wood, and other impurities on the surface, being then removed, the eggs are eaten raw. I have myself tasted the eggs; they resemble sago, and possess a very peculiar aroma. In the spring of the year marriages become frequent amongst the natives, no doubt on account of the profuseness with which the gifts of nature are then distributed. As it may be interesting to know the mode in which this family affair is conducted, I have thought fit to subjoin the following short account. The young man who wishes to marry, has first to look out for a wife amongst the girls or leubras of some neigh- bouring tribe, and having fixed his choice, his next care is to obtain her consent. This being managed the happy couple straightway elope, and remain together in the bush for two nights and one day in order to elude the pretended search of G 74. Rules and Tables adapted the tribe to whom the female belonged. This concludes the the ceremony, and the young man then returns with his wife to his own tribe. He is, however, laid under this peculiar in- junction, that he must not see any more his mother-in-law ; and the following circumstance in connection with this fact, has been related to me by Mr. Grant, an eye-witness. “A mother- in-law having been descried approaching, a number of leubras formed a circle around the young man, and he himself covered his face with his hands ;—this, while it screened the old lady from his sight, served as a warning for her not to approach, as she must never be informed by a third party of the presence of her son-in-law.” The natives, however, of this, as of every other settled part of Australia, are fast disappearing before the rapid encroachments of the white man; in perfect accordance with that universal but mysterious law which governs civilization wherever the white man has planted its flag, sweeping the backward races from the face of the earth. Art. VI.—Original Rules and Tables adapted to Cases of Sidelong Ground in the Setting Out and Computation of Railway Earthworks, By CLEMENT Hopexrnson, C.E., District Surveyor. HAvinG originally investigated and computed the following formule and tables for my own use, I venture to submit them to those members of the Philosophical Society who belong to the Engineering Profession. Before giving my tables for determining the side distances’ that define, on sidelong ground, the edges of railway eut- tings and embankments on both sides of the central line of equidistant stakes, I will’ briefly state the methods that have been generally followed for determining side distances. First.—Instrumentally; by means of the well known combination of graduated bars and arcs devised by Sir John Macneil, which, when the sidelong inclination on either side of any stake had been determined by a clinometer or other instrument, admitted of being adjusted so as to show by inspection, on a graduated bar, the required side distance. Sir John Macneil’s instrument is not however applicable to those constantly recurring cases in which a To Railway Earthworks. 75 railway is partly in cutting and partly in embankment on the same side of a centre stake. Second.—By successive approximations with the aid of the spirit-level. This method, which has been found well adapted for uneven ground, has been explained in detail in the work of Mr. Frederick Sims, C.E., lately Inspector of Railways for the Hon. East India Company; and has been very frequently employed by other engineers. I however noticed, some years ago, that his rule for determining the side distances, when the cross section showed both cutting and embankment on the same side of any centre stake, was totally wrong, and had occasioned errors of several feet in side distances set off for the South Hastern Railway. As Mr. Simm’s work has passed through several editions, and as _ the erroneous rule alluded to has been since given in another work brought out by the well known publisher, Mr. Weale, I trust this passing allusion to it may not be considered un- called for.* Third.— By plotting the cross sections of the ground upon a large scale, and taking the side distances from the diagrams. Fourth.—By various rules of thumb in vogue among con- tractors, and not admitting of mathematical demonstration. Having considered it would be preferable to employ tabu- lated quantities for determining side distances, in lieu of employing Macneil’s instrument, I have derived from the following formule the annexed tables of multipliers, and I have found that by using these multipliers (which are also applicable to those cases wherein Macneil’s instrument fails to be of service), the required side distances can be com- puted and set off on the ground with more rapidity and cer- tainty than by an instrument whose bars and arcs have to be adjusted at every stake. Let a B c p(Fig. II.) represent a portion of the cross sec- tion of a railway cutting on one side of the centre stake at H: the ground, in this diagram, converging from the centre stake towards the plane of base at formation leyel. Draw * A point being assumed as near the true position of the point p (Fig. I.) on the ground as can be determined by estimation, then the differ- ence of level between that point and the central stake u, minus the height 8 u, would be the first approximate value of p n, which multi- plied by ratios of slope for embankment, would give the first approxi- mate value of c x; which should be added in order to obtain the first approximate yalue of the side distance, B N, to B ©, the half-width at formation level, and not to & 0, the computed horizontal half-width for the height B H, as in Mr. Simm’s treatise. 76 Rules and Tables adapted H L, D O, parallel to base a Cc, and D K perpendicular to H L. Now let 2 denote half base or B Cc. h the height B H at centre stake. m : 1 rate of inclination of slopes. angle of inclination of sidelong ground. x the required horizontal side distance, or C D Then D K = 2 tang 6 bie h+m—ez DK=> — m m b > thm—ez x tang } = 27 — m 1 Cara : + hm (=a) In Fig. III., in: which the sidelong inclination diverges from the centre stake in reference to the plane of the base, we obtain, in a similar manner, e. . BAN ill ei Side distance or x = § +hm ( I tang 0. 7 ) In Fig. IV. let the profile of the sidelong ground cross the half base, and occasion cutting and embankment on the same side of the centre stake. Here D K + HL = HL tang 6. tile DK —=HLtang}—KL—=zg, tangi—h cK x—b DK ae on, - z—b a. tang 8 — h = = m 1 z—=b—hm (a5 1 — tang 6. m In Table No. I. I haye given values of men for the more ordinary slopes, and in Table No. II. similar values of : 1 + tang 5. m INCLINATION. To Railway Earthworks. TABLE—No. I. 1 1 — tang 6. m SLOPES. 1 tol 1-000 13 to 1 1-000 1-004 1-009 1-013 1:017 1-022 1:027 1-031 1:035 1:039 1044 1:049 1054 1:059 1:064 1:069 1:074 1:079 1-085 1:090 1095 1100 1105 L111 1117 ee i127 11133 1139 11145 1151 1157 1163 1169 1175 1181 2 to 1 1-000 1.006 1-011 1:017 1:023 1-029 1:036 1:042 1:048 1:054 1:061 1:068 1075 1:081 -1:088 1-095 1°102 1109 bel 1¢ 1124 1131 1139 1°147 1°155 1163 caver 1179 1°187 1°195 1:203 1212 1221 1:230 1:239 1-248 1:257 2% to 1 1-000 1-009 1:014 1:021 1:028 1:036 1:044 1:052 1:060 1:068 1077 1:086 1°096 1:105 1114 1123 17132 1141 15k 1161 Lt7d 1181 17191 1-201 1-212 1:223 1:234 1245 1:256 1-268 1:280 1:292 1-304 1:317 1-330 1:343 78 Rules and Tables adapted TasBLE—No. I.—continued. SLOPES. INCLINATION, ltol 14 to 1 2 to 1 2: to 1 =) 6— 0 1118 1°187 1:266 1°356 10 17121 1:193 1:276 1-370 20 1:125 1:199 1°285 1:384 30 1:129 1:205 1°295 1:°398 40 1'132 1:212 1°305 1°4138 50 1136 1:219 1°315 1°498 ° 7— 0 1'140 1°226 1°325 1-443 10 1148 1:232 1°335 1-458 20 1°147 1:239 1°345 1-474 30 1151 1:246 1°356 1-491 40 1:155 1:253 1°367 1:508 50 1°159 1:260 1:378 1:525 8— 0O 1°163 1:267 1°390 15542 10 1:167 1:274 1°402 1:550 20 1:171 1:281 1414 1:578 30 1:175 1:288 1°426 1:597 40 1:179 1°296 1438 1-616 50 1:183 1°304 1°451 1:6325 9— 0 1°188 1°312 1°464 1:655 10 1:192 1°319 1°477 1:675 20 1°196 1°327 1°490 1:696 30 1:200 1°335 1°503 1:718 40 1-204 1°343 1°517 1-741 50 1-209 1°351 1°531 1:764 10— O 1-214 1°359 1°545 1-788 10 1-218 1:367 1°559 1:81:13 20 1-222 1:376 1°574 1:839 30 1-226 1°385 1°589 1-865 40 1:231 1°394 1°604 1:892 50 1-236 1.403 1690 1:919 lil— O 1:241 1°412 1°636 1:947 10 1-245 1:421 1°652 1:976 20 1:250 1°430 1°669 2-006 30 1:255 1'4389 1°686 9°037 40 1-260 1°448 1°704 2°069 50 1:265 1°458 1°722 2°102 12— O 1:270 1°468 1°740 2°136 10 1:275 1°478 1°759 2-171 20 1-280 1'488 1779 2°207 . 30 1:285 1°498 1:799 2°244 40 1:290 1'508 1°819 2:283 50 1295 1519 1°840 2°323 To Railway Earthworks. TaBLE—No. I.—continued. INCLINATION. SLOPES. 13 tol ——— 1:530 1°541 1°552 1:°563 1574 79 23 tol a 2°365 2°408 2453 2°600 2°549 2°601 2‘655 o-7 15 2°769 2:830 2°893 2°960 3:030 3-104 3°182 3°264 3°350 3°440 3°534 3°633 3°740 3°855 3°978 4:109 4°250 4°402 4565 4°739 4924 5°120 5°328 80 SIDELONG INCLINATION. Rules and Tables adapted TABLE—No. II. i 1 + tang 5. m SLOPE SLOPE SLOPE 1tol 15 to l 2 to 1 1:000 1:000 1:000 “997 ‘956 “994 “994 “991 "988 991 °987 "982 "988 “982 “977 *985 ‘978 971 ‘982 ‘974 “S66 977 "967 "956 "972 "958 © °945 "966 °951 *935 “961 943 "924 "956 °936 “915 “950 °928 “905 °945 *920 *896 *940 “912 °887 "935 °905 °878 “930 “898 -869 *925 *89] ‘860 -920 °884 © "851 “915 °877 "842 -910 $70 °834 “905 -863 *826 ‘900 *857 *818 *895 *851 810 “890 -846 “802 *885 -839 “79 4 “881 -833 787 *876 *826 *781 °871 *820 "773 *866 *813 *765 “862 “808 *759 “858 *802 Whee "854 *796 *745 *850 ‘790 739 "845 *784 733 °841 778 ‘726 SLOPE 23 to 1 1-000 "986 980 ‘973 "959. "946 "933 “909 897 885 °873 “861 *850 *839 “829 °819 -809 -800 “791 *782 ‘773 *764 *796 *748 *740 732 724 “7d -709 ‘701 “694 *687 *680 To Railway Earthworks. 81 TasLE—No. I].—continued. SIDELONG. SLOPE | SLOPE SLOPE SLOPE INCLINATION. 1ltol 13 to l 2 to 1 23 to 1 ° n l1l— O 836 “772 719 "673 20 832 *767 713 "666 40 828 *762 °707 659 12— 0O 824 ‘758 “701 653 20 820 "753 "695 646 40 816 °748 "689 640 13 — O 812 743 683 634 20 808 ‘738 677 628 40 804 °733 672 622 14— 0O 800 °728 °667 616 20 796 723 661 610 40 792 718 656 604: 15— O 788 713 650 598 20 784 708 645 592, 40 780 “703 640 587 16— O leh *699 635 582 20 773 *694 630 577 40 769 *690 625 572 17— 0 763 °685 620 567 20 761 "680 615 562 40 757 676 610 557 18— 0O 754 672 606 551 EXAMPLE OF APPLICATION OF TABLES. 0 ) an 3 a a & oP Sidelong Tabular Required Nature of |a 2 a ae |S25e Inclination. multipliers. side distances. earthwork. ja | & | 3 ES $3 | ie a olg E gc| Left. | Right. | Left. | Right. | Left. | Right. +5 | | OO o —| | | —_——__ _ Cutting |46)30|1t01|102| 25-2 | 6°30" | 6 0! | -903 | 1-118| 228 | 282 do |47\dol do | 7 | 21 | 620} 4 40| -900 | 1-088| 189 | 22:8 do |48\do| do | 34/184 16 0/6 0|-905 | 1118] 167 | 206 do lagldo] do | 1:2} 162 | 5 40 | 5 30 bana 1-106| 15-5 | 17-9 Embank. 50\doj1Z-1) 3 | 19°59 | 5 20 | 5 20 {1-168 877 | 22°7-) 17-1. H 82 Rules and Tables adapted The tabular multipliers corresponding to angles of eleva- tion for cuttings, and depression for embankments, are taken from Table No. I.; and those corresponding to angles of depression for cuttings, and elevation tor embankments, are taken from Table No. II. Whenever the product of the horizontal half width (in column 6), by a tabular number, is less than the half base, it is an indication that there will be both cutting and embankment on the same side of the cen- tre stake. This is the case on the left side of stake No. 49 of the given example; and the required side distance, in this instance, is obtained by deducting from the half base, or 15, the product of the height 1:2 by the slope of embankment 14, and then multiplying this difference by the corresponding tabular number 1:175, taken from Table II., in accordance with the Formula No. III. Formula for occasional use in computing the volume of a por- tion of a Cutting or Embankment between two consecutive centre pegs, when the sidelong inclination differs considerably at each peg. I VENTURE to submit the following investigation of the volume of earthwork having rapidly changing profiles; as any rule that would tend to the attainment of greater ac- curacy in the computation of cubic contents in such cases, might be sometimes applicable in this colony, where the great cost of earthworks renders precision in the estimated contents thereof a matter of very great importance. The French have made long and complicated investigations in connexion with the subject of deblais and remblais, but their formule are too abstruse for any practical application, and their tables for facilitating ordinary computation of earthwork, are less convenient than Bidder’s improved tables and some others in use by British engineers. I am indebted to the French for the hypothesis of the mode in which the surface of the ground may be conceived to be generated in the following investigation ; but the in- vestigation itself, and comparatively simple formula obtained, are my own. Let ABCDEFGH(Fig. V.) represent a portion of railway cutting between consecutive stakes, and let the sidelong angle of inclination H G H’ be not equal to the sidelong angle of in- clination D Cc D! at the other end of this earthwork. In the first place it is evident that the surface D C G H is not a plane surface, but a contorted surface, and it may be conceived to | Fig 6. i im] / A y fro ho may 8S Ob8, We lleurine. ———— DSS ee To Railway Earthworks. 83 be generated as follows :—Let a line in the position c & slide along the lines C D, G H, in such a manner that it may pass over respective distances on each line continually propor- tional to C D, @ H; then, when this moving line arrives at D it arrives simultaneously at H. This moving line would generate a contorted surface that might be, for several rea- sons, assumed to be equivalent to that of the railway cutting DCGH. The volume of a solid founded on one side by a contorted surface generated in the manner just described can be mathe- matically determined. Thus, let aBCDEFGH(Fig. VI.) represent a solid whose base, A BC D, is a trapezoid, whose sides are planes perpendicular to the base, and which is bounded above by the contorted surface E F G H; now, if s denote area of triangle A B C Ss, ... area of triangle Ac D See Be acta OR pa saat Ee | CPE AS 5: It can be demonstrated that volume of solid 3 Reverting again to the prismoidal portion of cutting bounded aboye by the contorted surface assumed to be ge- nerated as described, Let denote the base a B d .. the length BF 1 Hae ets DR U ae oe HO ? pA ce ace re soe in Gee mtol ... the slopes V ... the required volume. V=RQPODCGH—ADREHO—BEQFGP of which RQPODCGH=}RQ. ar Cure See ree) $tor. Cr Gaeta ee) or, zaropcan—%} (Geese ical 9 naam Casas) ADBEHO—4G nt im+ilm) boISIP—1 i mirm teem) 84 ules and Tables adapted to Railway Earthworks. Consequently, Vad { (2-41 m4 wa). (Dei ctary (ie mp0! im). (Upat-plfr) (Cmpt! ml I in tinea Ee Yr m) } Effecting the multiplication and reduction of the terms we obtain _) (Ath). Of Fr tp r\( 4 ) ( 3 3 5} ¢ Example. Let height to right at one end of cutting or 7 = 20°5 height to left dae ad [= 27-4 height to right at other end r= 32-1 height to left at other end i — 38-4 length oe d — 100 base b= 30 slopes see i — 20°5 27-4 38°4 27:4 19:2 13°7 32°1 = Beat 38°4 46°6 52°1 a 20°5 32:1 4)118°-4 7 is 2330 521 29°6 9320 1042 30 1563 —__—_ 955°30 ae See 888 1672-41 1672-41 2627-71 2 3)5255-42 1751-80 888 2639°8 100 263980: cubic feet = 9777 yards. fl eda way Be Sams Melbourne On Ascertaining Mean Temperature. 85 ‘Art. VII.—On the Construction of an Instrument for Ascer- taining the Mean Temperature of any Place. By Dr. E. DAVEY. To ascertain the mean temperature of the year, and especially of particular months of the year, in different regions of the world, is an object of prime importance in Meteorology. The mean temperature of particular days is also of interest, though much less important. The mean temperature of the year may be pretty nearly inferred from observations on the heat of the earth, at a certain distance, say ten feet, from the surface, where it is almost beyond the reach of influence from the seasons; and the results thus obtained will probably be almost exact if taken at opposite seasons of the year. By this method, how- ever, we are informed rather of the average temperature of a succession of years, than of any. particular year, and we are by no means enlightened as to the differences of the seasons. The mean temperature of particular days may be, of course, ascertained by hourly observations on the thermometer, and taking their mean ; and the temperature of the month would be calculated from the mean of the days. This method is, however, obviously. too troublesome to be carried into practice. It was remarked by Humboldt, from observations made in France, that the temperature at sun-down, is in general pretty nearly the mean of the highest and lowest of the twenty-four hours: the lowest being at sun-rise, and the highest, about two hoursafter noon. He preferred, however, to take the actual mean of the two extremes. ‘These extreme points may be very exactly ascertained by means of the instru- ment well known as Six’s day and night or register thermome- ter, which leaves a mark of the highest and lowest points which the thermometer has attained since the last previous observa- tion. The description of my sensitive thermometer pendulum has reference to the drawing. It consists of a glass tube, fixed upon any suitable frame, A being the axis of oscillation. The glass tube is bent in the form of a reversed syphon, of which each limb, but necessarily the limb G E F, is upwards of thirty-two inches in length. It contains three bulbs, of which the bulb B and part of C D down to D. with the intervening tube contains air.—The remaining portion of the bulb C D and part of the bulb E F and intervening tube, 86 On Ascertaining the from D to E is occupied by mercury, and the remainder of the bulb E F'isa Torricellian vacuum, the tube being hermeti- cally sealed at both ends to exclude barometric influence. The effect of heat will be to expand the air in the bulb B, and by the increase of its pressure to force the mercury out of the bulb C D into EF, the upper part of which being vacuum will offer no resistance. The weight being thus removed nearer to the centre of oscillation, will be tanta- mount to a shortening of the pendulum, and will cause it to vibrate more rapidly, and in exact proportion to the tem- perature, as it is well known that the expansion of air is uni- form with every increment of temperature. A drop of oil on the surface of the mercury in C D, and the substitution of hydrogen gas for air in B would probably add to the perfection of the instrument ;—the object of the oil being to prevent the transfer of air into the vacuum, and the hydrogen to obviate the action of common air on the oil. By a slight and obvious modification of this instrument a sensitive air thermometer may be constructed. It is, however, obvious that the true mean temperature is not necessarily the same.as the mean of the two extremes of the twenty-four hours. The thermometer may have been for many hours near its highest point, and for a short time only near its lowest, or vice versd. The force of this objection becomes considerable in a climate like this, where a change of temperature to the extent of thirty degrees is not unfrequently known to occur during a single hour. Admitting, therefore, the value of Six’s thermometer, as registering in a most con- venient manner the extremes of heat and cold, it cannot, I think, with propriety be depended upon, as an instrument affording data from which to calculate mean temperatures, except approximately; and this approximation may be seriously remote from the exactness which modern science demands. I now proceed to describe the principle of the instrument which I propose for ascertaining mean temperatures. It is well known that the pendulum of a clock vibrates more or less rapidly according to its length; that the pendulum is elongated by heat and shortened by cold; and consequently, that an ordinary clock has a tendency to go slower or lose time in warm weather, and to gain time in cold. The effect of slight changes of temperature upon an ordinary pendulum is very inconsiderable; but, if we can succeed in constructing a pendulum, which shall be highly sensitive of heat and cold, Mean Temperature of any Place. 87 to such an extent, for instance, that the variation of one degree of Fahrenheit’s thermometer shall cause the clock to gain or lose five minutes a day; we shall at once have an instrument which will register the temperature of the aggre- gate of every vibration it has made. ART. VIIL—Meteorological Observations at Bendigo. By Lupwig BEcKER, Esa. In the present paper I am desirous to give the result of my observations on the weather, at Bendigo, during a period of fifteen months, viz., from the 1st December, 1852, to the 28th February, 1854. Durimg which period I have prepared complete meteorological tables.* During my stay at Bendigo I was unable to procure either a barometer or a thermometer, and the stated grade of tem- perature met with in the tables was kindly furnished to me by a gentleman who was fortunate enough to have been in possession of the necessary instruments. My especial object in preparing these meteorological tables is, that in connection with, and compared to, later observa- tions, it should tend to fix the character of the seasons and °* their phenomena. So far as I have had the opportunity of observing the character of the weather at Bendigo, I have come to the following conclusions :— 1. Prevailmg winds come generally from N. W., most of the rain coming from the same quarter. 2. During the day there is more or less wind, followed by a calm and clear night. 3. Warm days and hot winds are generally succeeded in the evening by a cold southerly wind, as if the effect of the sea breeze extended as far inland as Bendigo. 4. The hot winds announce themselves in the morning by a thick hazy atmosphere, with a light south-easterly breeze ; the wind, increasing in force, veers from south-east to east, and gradually wears round to the north-west, which ends in a cold south wind, thus making a perfect circle ; the greatest heat is felt when the wind is blowing from the north-west ; the hot wind is generally followed by rain. 5. The whirlwinds prevailing during fine weather and gentle breezes, but do not indicate rain. * The original meteorological tables are deposited in the Museum of Natural History. 88 Meteorological Observations at Bendigo. 6. During very hot and.dry weather I have found my opossum rug discharging electric sparks, with a cracking noise, when rubbed with the hand; sometimes I observed a similar electric phenomenon, although in a less degree, on a common wool blanket. 7. There are few thunderstorms, compared to those in other countries, although the atmosphere seemed to be fully charged with electricity. Very vivid flashes of lightning, marked with the peculiarity of always taking a perpendicular direction, were accompanied by heavy showers. 8. The atmosphere is generally clear, and the stars visible, even close to the horizon, with but a very slight scintillating appearance. The firmament is more blue than that above Melbourne, but less brilliant than in Van Diemen’s Land. Fogs I observed only twice or three times, early in the morning, lasting, however, but a very short time; never- theless, the atmosphere is occasionally of a yellowish-grey colour, which is the effect of the large bush fires, which occasionally originate during hot winds. The opinions of the causes of bush fires are various; according to my observations, it may be attributed: — To carelessness with camp fires, &c. To a slumbering fire in a hollow tree, in places where the bush fires seem to be extinct. In such hollow trees, for several weeks, the fire is smouldering, and, during the hot winds, is fanned into flames, and thus communicates to the parched vegetation, sometimes at a very great distance, not only sparks, but burning charcoal of considerable size. In places far in the interior, where no man could be supposed to have penetrated, the origin of bush fires can be attributed to lightning, and to the friction of dried branches, during the hot northerly winds. One could scarcely imagine, without having seen it, what power these winds exercise upon the branches of a tree, and what a peculiar noise is produced by the friction of the branches, during the prevalence of the gale. Considering the friction of thousands of branches in the forest, aided by a high temperature, scarcely endurable to animals, it sufficiently accounts for those fires in the interior, the origin of which could be attributed to no other agency, except, perhaps, lightning. 9. Frost is not unfrequent during the winter season ; ice, however, is seldom seen, and rarely attains the thick- ness of a quarter of an inch. Snow I did not observe dur- ing the whole of my stay at Bendigo, - Rain and storms are ~ Meteorological Observations at Bendigo. 89 prevalent in the winter season, which generally begins in May and ends with October. The days and nights are often very cold; sometimes, however, even in the winter season, I have experienced a warm calm day, followed by a clear starry night. 10. Of shooting stars or aerolites I have seen but few; and during the months of August and November, which it is well known are those in which they are most numerous, I did not observe a single one, although I looked for them on many nights. 11. The Zodiacal light appeared often so luminous as to be almost equal in brilliancy to that observed within the tropics. 12. At Bendigo I never observed any Aurora Australis; but in Tasmania, where this beautiful phenomenon is frequent, I have witnessed most brilliant displays. 13. One of the most striking peculiarities of Bendigo consists in the sudden and violent currents of wind from the north-west; these are of frequent occurrence, and of short duration. I will here avail myself of a few lines from my diary, descriptive of this remarkable phenomenon. “Night. At a great distance, apparently of several miles, in a north-westerly direction, a peculiar rushing noise is heard, which approaches closer and closer, becomes more distinct, till at length it grows into the boisterous tumult of a hurricane. The inmates of the tents are alarmed, and cry out the well-known seaman’s call, “ stand by the royal halyards.” Tt is a heavy squall approaching, and the warning voice serves to the inhabitants of the gullies as a hint to secure their tents against the violence of the approaching tempest. A few minutes later and we find ourselves in the midst of the storm; the air is filled with dust, mtermixed with myriads of burning sparks, lifted from the numerous fire-places. The hurricane is so violent that it destroys and carries away tents, shakes substantial buildings, bends and breaks trees; and, after this storm of a most violent nature, a heavy shower follows, reminding one of an approaching deluge, and in a few minutes everything is again clear and calm. The dark cloud, charged with destruction, and which has imparted terror to every living being, is now to be seen far away on the horizon, wearing towards the south-east, and only a roaring noise is to be heard, something like ag the receding sounds of the Niagara Falls, becoming fainter and fainter, until at a vast distance it dies away.” I 90 Meteorological Observations at Bendigo. 14. The beautiful constellation represented in the accom- panying diagram I was fortunate enough to witness. It took place on the 4th November, 1853. During the summer season the mining population suffers from inflammation of the eyes; the cause of this evil may be attributed to a small kind of fly, which, having gone into the eye, sucks the moisture of that delicate organ, and causes a peculiar itching sensation ; to relieve this, the sufferer has recourse to rubbing the eye, which cannot fail to injure it. I believe that the great heat of the solar rays, reflected from the gold-fields and the numerous white tents, may be considered an additional source of injury to the eye. One of the chief causes of inflammation of the eyes may be the caterpillars. These creatures web themselves on trees. in the months of January and February, the time when the blight is most frequent, leaving behind them a great number of small hairs, covering the web as well as the wood. If this is used for domestic purposes, the hairs, coming in contact with the eye, either by rubbing it with the hand that handled the wood, or by other means, produces inflammation, exactly similar to what is produced in Europe by the migrating caterpillars. I never suffered in the eyes, as I was careful to take the precaution of smearing oil over my face, this being the best remedy to keep off insects. The aborigines of different countries are well aware of the useful application of oil; they smear and grease the whole of their bodies, to provide against being bitten by musquitoes and other insects. It is desirable to avoid touching the eyes with the bare dry finger; and veils and coloured eye preservers are therefore used at the Diggings as a means of protection. In the month of April, 1853, nearly all the dogs at Ben- digo were afflicted with the distemper, and I was informed that a great number of native dogs perished by the same cause. At the same time, the Bendigo population suffered: much from influenza and rheumatic pains. It is questionable whether man and beast did not suffer from the same cause. One great principle should be observed by every one resident in this colony, viz., to dress warm at night. To this effect an example is furnished to man by various animals indigenous to Australia; amongst others the opossum, which feeds dur- ing the cool nights on lofty trees. The effects of the sudden change of temperature is mostly felt by new arrivals, and by the less cautious of the mining population. During the heat- “YaLldnNe “VNAT “SMNAA O s[pieuep acksaurg 19q ‘s8xp9g 'T ac ee ae ts ‘ ba! Tin whit 9 pegs Meteorological Observations at Bendigo. 9t of the day, the diggers, as well as other working-men, are dressed in light apparel; and if they are not cautious to change their clothes, for warmer ones, during the night, they will soon experience the effect of their neglect. At the end of the day’s work the tired man falls into a deep sleep, not awakened even by the effects of the cold, which penetrates through the tent, and injures his health. The man next day feels feverish, diarrhcea precedes the dysentery, and not unfrequently it is followed by typhus, which generally ends in the death of the suffering man. The prevailing diseases are greatly assisted by the popula- tion not living according to their adopted climate. Most of them transfer to this colony the mode of living which they have been accustomed to in a climate lying twenty degrees further from the equator than Victoria, without allowing one degree of change in their habits. They drink here the same spirituous liquors as they did at home; they consume the same great quantity of animal food, washed down by a deluge of tea, as if the same misty sea air surrounded them here that did in England, and which allowed the consumption of of a greater quantity of animal food and‘strong drinks. To this effect I beg to quote Streletzki’s remarks upon the sub- ject, in his work on New South Wales and Tasmania :— *“ No endemic disease, and seldom any epidemic of grave character, prevails; and if individual indisposition, or even partial deterioration of the progeny is sometimes seen, it is to be traced to the pertinacity with which the English race cling to their original mode of living, wherever they settle, and however different their adopted country may be to their native climate. It is to the abuse of strong wines, malt liquors, and spirits, and particularly to the excessive con- sumption of animal food of the richest description, and even to the mode of clothing and housing, that individual disease, such as dyspepsia, premature decay of teeth, and affection of the brain may be attributed.” The state of the health would be much improved in this country if the inhabitants, instead of the strong beverages used at present, would drink pure water, light beer, or native wine, which could be produced in this country, and consume more vegetable food and fruit. About the mode of living in Australia I shall have the opportunity of giving my opinion on a future occasion, it being here out of place to treat on this subject. I will, however, observe, that the climate of this country is healthy, though not so the men. 92 Influence of Gravity on the Art. IX.—On the Influence of Gravity on the Physical Condition of the Moon’s Surface. By BALFOUR STEWART, Esq. THE great irregularities of the surface of our satillite, are discernible almost without the aid of a telescope, but, by means of this instrument they have been accurately measured ; and their stupendous character impressed upon the mind, which is thus enabled to compare them with the irregularities of the Earth’s surface. The appearance presented by the moon’s disc, is thus described by the Rey. Josiah Crampton, in his work entitled Zhe Lunar World; its Scenery, Motions, &c. “Not only,” he remarks, ‘‘are her mountains more numerous in proportion to her size than those of the earth, but they are much larger, rising to a much loftier elevation, composed apparently of a stibstance of a much harder texture than any thing terrestrial, and exhibiting _ bolder and sharper outlines, and more tremendous precipices, some of which project and overhang each other in such a manner as to lead many to suppose that the rocks composing them are of a harder and more solid nature than wrought iron.” And the Dublin University Magazine, for February, 1854, remarks on the same subject. ‘Some important diversity must prevail, no doubt, for it cannot be by chance, that inthe lesser body sheer cliffs of thousands of feet des- cend from mountain tops into the valleys or chasms, while in the larger, no search has yet succeeded in discovering a perpendicular descent of five hundred feet anywhere. The moon’s craters cling to the sides of cliffs, cut into, encompass, and over-leap each other. In dimensions some of them measure one hundred miles.” With regard to the cause of this diversity I would venture an explanation. I do not look for it in any difference of material; for I am neither inclined to imagine with some that the moon’s surface has more tenacity than wrought iron, nor with others that it resembles cork. I would rather look for its chief cause in the difference between terrestrial and lunar gravitation. A long rod of iron will bend, and a sufficiently long rod of any brittle substance will break by its own weight; but if these be placed in circumstances where they retain their tenacity and all their other qualities unchanged, with the exception of their gravity, which is lessened, the rod of iron will not bend so much, and it will require a greater length of the brittle substance in order to break it. Now the weight of the same body is much less on the moon’s surface than on the earth’s. For the attraction of a sphere of matter on any point, without its force and distance, is the Physical Condition of the Moon's Surface. 93 ‘same as if all the matter of which the sphere is composed were collected in its centre. Now, if there be two spheres, of the same average density, the attraction of either for a point on its surface wili be equal to that produced by the whole mass acting from the centre; and, since attraction varies inversely as the square of the distance, that on the point will vary as “2 viz., it will vary altogether directly as the radius of the attracting sphere. Now, according to Humboldt, the diameter of the moons 1816 geographical miles, and the mean diameter of the earth is 6864 geographical miles; hence, supposing the density of these two bodies to be the same, these numbers will represent their proportional attraction for a point on their surface. But if the density of our earth be denoted by (1), that of the moon, (according to Humboldt), is only °619; if, therefore, lunar gravitation be reckoned unity, terrestrial gravitation will be found from the following compound proportion :— ISIG— 5 6804 ost on ee ONG) The result of which is 6-1 for the value of -terrestrial gravi- tation, or upwards of six times that of lunar gravitation. We need not therefore be surprised at matter remaining stable on the moon’s surface, in a position from which it would be hurled by its own weight if on the earth’s surface. And if we suppose that gravitation has exerted a direct influence in rounding the irregularities of the earth’s surface, we need not be surprised if the moon’s surface be less rounded, and more mountainous and irregular. In like manner, were each square inch of the moon’s surface charged with the same mass of atmosphere as the- same extent of the earth’s surface, its tension would be less, because its weight would be less. It would therefore be less condensed, and would not lie so closely to the surface as on our earth, but would spread to a greater distance from it. Take a star near the edge of the moon. We may consider the star as a luminous point so distant that the rays which fall upon the eye form a parallel pencil in passing near the moon, and through its atmosphere, if there be any. But the mass of material particles which such a pencil will encounter in its passage through an atmosphere will vary, not only with the total mass of that atmosphere, but also with the manner in which the atmosphere is attached to the surface of the planet. The following approximate demonstration may serve to make my meaning plain. 94. Influence of Gravity on Moon's Surface. Case 1st. Let the atmosphere (Fig. 1) be so closely at- tached to the surface, that its depth is very small compared with the radius of the planet. Let a Bc be part of a great circle section of the planet, let a’ B’ be the boundary of the atmosphere, and by an alteration of circumstances suppose this atmosphere afterwards extended to 4” B”. By this latter supposition the same amount of atmospherical particles will be included in the solid, represented sectionally by a a” B” B, as was formerly included in a 4’ B’B. But the solid a a” B” Bis to the solid A A’ B’ B nearly as A A” is to A A’, that is the amount of atmospherical particles included in a given space varies (ceteris paribus ) inversely with the depth of the atmosphere. But the length of the pencil of light exposed to the action of the atmosphere varies nearly in proportion to the square root of the depth of the atmosphere, therefore the closer the atmosphere lies upon the surface, the greater will be the mass of particles which the pencil has to encounter. Case 2nd. Suppose (Fig. 2nd) that the depth of the at- mosphere is very great in comparison with the radius of the planet. Here the solid a a’ B’ B is to 4 A” B” B very nearly as (A A’)?: (A A”)? or as the cube of the depth of the atmos- phere, but the length of a pencil of light passing near the planet immersed in the atmosphere will vary directly with the depth of atmosphere, hence in this case also, the deeper the atmosphere the fewer particles will the pencil encounter. These are the two extreme cases, and perhaps this demon- stration is accurate enough to entitle us to conclude that when a given mass of atmosphere is closely attached to a planet, a pencil of light passing close to the surface will en- _ counter a greater mass of particles, and probably deviate more from its direct course, or in some other manner indicate the existence of an atmosphere than when the same mass of atmosphere is more loosely attached. If, therefore, each square inch of the moon’s surface were charged with the same mass of atmosphere as the same extent of the earth’s, it would not (ceteris paribus ) cause a star to deviate so much as the terrestrial atmosphere. It might also be shown (Fig. 3rd) that were the atmosphere in precisely the same state for both planets, the pencil would encounter more particles in the atmosphere of the larger body being immersed in it to a greater length. And, finally, if the amount of atmosphere be proportional to the mass of the planet, we cannot look for the same mass of atmosphere on each square inch of the moon’s surface as on the same extent as our earth’s. - These Fict Redouwiuny ehome Melloure Aduptation of the Eye. 95 three considerations taken jointly induce me to think that the moon may have an atmosphere, although such may not come within the range of our observation. Art. X.—On the Adaptation of the Eye to the Nature of the Rays which emanate from Bodies. By BALFOUR STEWART, Esq. In the following remarks I assume, along with Professor Provost, that bodies radiate at all temperatures, only the hot- ter bodies radiate more than they absorb, and the colder less, until a uniform temperature is at length attained. Now, in the spectrum formed by decomposing a ray of white light by means of a prism, the most refrangible rays are the violet and blue, and the least refrangible of the visible rays are the red; but there are yet a set of less refrangible rays, which though not visible to the eye, have the power of raising the thermometer. I conceive that all bodies at ordinary tempera- tures emit rays of this description, which are less refrangible than the extreme red of the visible spectrum, and that as the temperature of a body rises, the average refrangibility of the rays it emits rises also, and to the same extent for all bodies, until at almost 600° Fahr. The rays enter the visible spectrum by the extreme red, and the body is now said to be red-hot. And here I may remark, that with regard to the absolute identity of the heating and illuminating rays, I hold the opinion of Professor Powell, expressed_in his report on Radiant Heat, in the Transactions of the British Association for 1840, where he says :— “ The question of the identity of the heating and illumina- ting radiators seems clearly negatived by many experiments, if we mean it to apply in the sense of one physical agent; but, if we refer to the possibility of accounting for the different effects by sets of undulations of the same etherial medium differing their wave lengths, this probably presents fewer difficulties than any hypothesis of peculiar heat.” - However this may be, if the temperature of a red-hot body be still further increased, the average refrangibility of the rays it emits is also increased to the same extent for all bodies; and it is now said to be white hot. If the heat be still fur- ther increased, it requires a greater number of the blue or more refrangible rays; such, for instance, as the lime-ball 96 Descriptive Characters of light charcoal points in a galvanic battery, and the light of the sun. Now, although we do not know by what property of the eye rays less refrangible than the extreme red become invisi- ble, yet this will appear on inspection to be a wise arrange- ment of Providence. For if the rays which emanate from bodies at ordinary temperatures were invisible they would overpower those exquisitely beautiful colours of nature which are produced by reflection of the solar light; besides which, there would be no such thing as darkness, even when the eye was closed, for light would still issue from the eyelids. And again, if rays did not become visible till at a much higher temperature than 600°, combustion would go on in darkness, and we should never be warned of the presence of fire. Finally, if we suppose a number of bodies (for simplicity’s sake spheres) to have been originally at the same temperature, it is clear, that since radiation will vary with the surface exposed, large spheres, the surface of which bears a less proportion to their solid contents than that of smaller ones, will cool more slowly than smaller ones; so that at any given time a large sphere would be at a much higher temperature than a small one, and would, consequently, emanate visible rays, while the rays of the other would be invisible. Therefore, in a system of bodies, such as the solar system, the centre of attraction is also the centre of illumination which is a most wise and beneficial arrangement. Art. XJ.—Descriptive Characters of New Alpine Plants, from Continental Australia. By Dr. FERDINAND MUELLER. In offering this small, yet perhaps not unwelcome contribution towards the botany of Australia, I wished to conclude the precursory diagnostic notes on our Alpine flora, of which some scattered fragments appeared in this journal, and in the papers of the Victorian Institute.* ; * The plants there enumerated and described are the following :—Hriostemon lancifolius, P. phylicifolium, Phebalium ozothamnoides, Ph. podocarpoides, Crowea exalata, Scleranthus miaroides, Kunzea ericifolia, Burtona subalpina, Oxylobium ~ alpestre, Bossiza distichoclada, Kurybia megalophylla, Eurybia alpicolo, Brachy- come, multicaulis, Br. nivalis, Antennaria nubigena, Gnaphalium alpigenum, Agrostis nivalis, Agr. frigida, Agr. gelida, Danthonia robusta, Hierochloe submutica, and Astelia psychrocharis. A few as doubtful remained yet uncharacterized. New Alpine Plants. 97 For further details on the position which the plants from our snowy mountains occupy in phyto-geography, showing how far they are endemic, how far connecting those of distant countries, and how far identical with those of other parts of the globe, and for information on their uses and peculiarities, I beg to refer to my published official reports. It remains here only to acknowledge, that without the use of the admirable Flora Antarctica of Dr. Jos. Hooker, and the yet unfinished Flora of New Zealand, from the pen of the same celebrated author, I should have been unable to analyze these plants regarding their distinctive characters with that precision which was earnestly desired, but perhaps not attained. ' RANUNCULACAE. 1. Ranunculus anemoneus. (Sect. Hecatonia.) Glabrous or hirsute; root fasciculate; stem thick, simple, erect, one-three flowered, below leafless, at the base vaginate ; leaves veined, the radicil ones on long and strong petioles, orbicular, to the base divided into three or five lobes; these deeply three or five-cleft, covering each other, their lobules variously cut, acute; bracteal-leaves large, cordate-orbicular, dissected, sessile, clasping ; peduncle naked or with a smaller bracteolar-leaf; sepals five-seven, ovate, appressed, slightly villose; petals large, white, generally numerous, twice or three times as long as the calyx, narrow oblong-cuneate, entire; nectar-pit solitary, margined; carpels turgid, even, glabrous, margined ; their style at the extremity hooked. On springs at the summit of the Munyang Mountains. This charming and interesting species forms, next Grevillea Victoria, the greatest ornament to the Snowy Mountains of Continental Australia. It differs from similar showy ones in New Zealand already, in its white petals, and approaches rather to the European alpine type of the genus represented by R. aconitifolius, glacialis, &c. 2. Ranunculus Millani. (Sect. Hecatonia.) Dwarf, stemless; root fasciculate-fibrous; scape simple, one-flowered, solitary, spreading-downy, of the length of or K 98 Descriptive Characters of shorter than the petioles; leaves pinnatisected, glabrous or together with the upper part of the petioles scantily downy ; segments few, linear, undivided or bi-trisected, terminated by a gland; sepals appressed, glabrous, nearly ovate, with membranous margin; petals five-ten, white, obovate or oblong-cuneate, almost twice as long as the calyx; nectar-pit distant from the base, margined, covered by a hardy percepti- ble scale; carpels few, glabrous, broad-ovate, compressed, margined, smooth, with a hooked style. In gravelly places on most of the summits of the Australian Alps, irrigated by the melting snow. I should have referred this neat little plant to the Tasma- nian R. nanus, were the discrepancy in the colour of the petals, a character of such validity in this genus, not too manifest ; for whilst to that species bright yellow petals are attributed, I found them always white in this, and assuming only a slight yellow tinge when drying. In selecting the specific name, I desired to pay a slight scientific tribute to the merits of A. M‘Millan, Esq., who not only forced, with skill and enterprise his way first into Gipps’ Land, opening one of the finest districts of whole Australia to civilisation, but who also named and first ascended Mount Wellington, where I became originally acquainted with this plant. 3. Caltha introloba. (Sect. Psychrophita.) Dwarf, leaves on long petioles, hastate-ovate, notched at the summit, perfectly entire, enlarged at the base by two long lobes; these bend inward, oblong-linear, below dilated ; scape with one flower, very short; sepals white, five-eight, deciduous, lanceolate-linear, acuminate; carpels five-nine, with three seeds, and a long straight style, reflexed at the top. ‘On gravelly places in the Australian Alps, irrigated during the summer months by the melting snow. Mount Hotham, Mount Latrobe, and Munyang Mountains. To be distinguished from C. Novae Zeelandie principally by its white flowers, and longer leaf-lobes. It is the only species known from New Holland. New Alpine Plants. 99 DIOSMEAE. 4. Phebalium ovatifolium. Leaves coriaceous, ovate, above smooth and shining, be- neath lepidote, their margin recurved; peduncles axillary, solitary, with a single flower and three or four bracts, com- pressed, twice or three times shorter than the leaves; teeths of the calyx triangular-lanceolate, glabrous ; petals lanceolate- ovate, whitish, little longer than the stamens; anthers affixed with their back ; filaments glabrous ; stigma capitellate, club- shaped; carpels apiculate. In the rocky or scrubby parts of the Australian Alps, at the sources of the Murray and Snowy River. That the genera eriostemon and phebalium are not strictly defined by clear and natural characters has been observed previously in other instances. This handsome species again may be referred to either of the two genera, which I would propose to unite. 5 Eriostemon trachyphyllus. Tall, smooth, covered with glandular warts; leaves herba- ceous, flat, entire, oblong-lanceolate, pointed, sessile, on both sides green, above shining; pedicels axillary, solitary, shorter than the leaves ; segments of the calyx subdeltoid, glabrous ; filaments fringed; style smooth; stigma five-cleft; carpels blunt ; seeds shining, black, grey-variegate. On the mountains at the Snowy River, near the Pinch Range, on rocks. A fine plant, as well allied to E. myoporoides as to E. intermedius. I beg to subjoin another rare plant of the order, although not alpine. 6. Eriostemon microphyllus. Dwarf; branches asperous; branchlets thinly covered with starry downs; leaves coriaceous, crowded, much spreading, ovate- or cordate-orbicular, scabrous, with recurved apex, on short petioles; flowers several together terminal, glandulose; segments of the calyx triangular-ovate, nearly smooth; fila- ments as long as the corolla, glabrous, gradually tapering into the apex; appendage of the anthers exceedingly small; style glabrous. 100 Descriptive Characters of On the low coast ranges of Spencer’s and St. Vincent’s Gulf, but only rare. Of unquestionable alliance with E. rotundifolius (AIL. Cunn. in enum. pl. Hueg. p. 15.) 7. Boronia algida. Fruticose, much branched; branchlets spreading or diva- ricate, velutinous, somewhat compressed; leaves on very short petioles, with two pairs of leaflets and a terminal one; these small, coriaceous, glabrous, obcordate or cuneate-ovate, with entire hardly recurved margins; flowers solitary twin or rarely several together without a common peduncle; pedicels on the base bracteolate, of nearly equal length with the ovate- lanceolate acuminate glabrous sepals; petals much longer than the glabrous filaments; style smooth, very short; stigma depressed-capitate. On the highest stony declivities of our Alps; for instance on Mount Hotham, Mount La Trobe, and Mount Koskiusko. A charming bush, allied to B. rubiginosa. CRUCIFERS. Blennodia. R. Brown. (Sect. Drabastrum.) Silique lanceolate, by its convex one-nerved valves almost tetragonal. 8. Blennodia alpestris. Perennial, dwarf; stems erect, nearly naked, thinly pubes- cent, rarely branched ; leaves lanceolate or ovate, toothed or nearly entire, gradually tapering into the petiole; flowers white, corymbose; style short; pedicels divaricate, of the length of the silique; valves distinctly one-nerved; seeds disposed in two rows, brown, minutely foveolate. In subalpine grassy places on the sources of the Murray and Snowy River. Erysimum brevipes, curvipes and blennodes (B. lasiocarpa msc.) are congeners of this plant, but as the cotyledons are at times slightly bent inward, I am uncertain whether the genus ought not to be united with Diplotaxtis or Moricandia. New Alpine Plants. 101 CARYOPHYLLEAE. 9. Colobanthus pulvinatus. Perennial, glabrous; stems numerous, moos-like tufted ; leaves densely crowded, rigid, squarrose, broad-subulate, channelled triquetrous, pungent, shining, with a slightly in- flexed mucro; sheats close; flowers terminal, solitary, on very short and thick peduncles, pentamerous ; sepals from a broad base lanceolate-subulate, hardly longer than the egg-shaped capsule, and nearly twice as long as the stamens. On the highest, barest, and gravelly tops of the Munyang Mountains. (6,000—6,500 feet.) This forms a near approach to C. Benthamianus, a native of Cape Horn and the Falkland Islands, and not yet found similarly presented either in New Zealand or Tasmania, but is apparently identical with the pentamerous form of C. Ben- thamianus from Campbell’s Island. Since also my plant in- variably shows a quinery division of the flowers, I have separated it from the South American one, following Dr. Hooker's suggestions in the Flor. Antarct., p. 247. STACKHOUSEAE. 10. Stackhousia pulvinaris. Depressed, with numerous intricate rooting branches, perfectly smooth; leaves somewhat fleshy, oblong or spathu- late-linear, nearly blunt; flowers solitary on the summit of very short branchlets; bracteoles twin, as long or longer than the pedicel; flowers yellow ; three of the stamens longer me the two others; anthers glabrous; style deeply bi- or trifid. On the highest summits of the Australian Alps, where satu- rated with moisture, the widely expanded tufts decorated with a starry flowers, form a beautiful carpet. (5—7,000 eet. As a species it connects the Tasmanian S. flava with S. minima, from New Zealand. UMBELLIFERAE. Dichopetalum. A new genus of Hydrocotylex. Flowers hermaphrodite, equal. Lobes of the calyx white, membranous, petaloid, of 102 Descriptive Characters of the shape of the petals, and with these deciduous. Petals sessile, ovate-elliptical, with a blunt not inflexed apex. Sta- mens shorter than the petals. Styles divergent, subulate, arising from thick stylopodia. Fruit laterally compressed, nearly ovate, glabrous. Carpels with five ribs, destitute of vitte. Carpophor undivided. A genus well defined by the perfect and constant equality of calyx and corolla, which unite to form a decapetalous flower, a structure without parallel in the wide order to which this fine genus belongs. The alliance, in other respects, to Xanthosia and Oschatzia is obvious. 11. Dichopetalum ranunculaceum. Stemless, prostrate, hispid; root thick; leaves on long pet- ioles, nearly round, three- to five-lobed; the lobes inciso- crenate; scapes numerous; umbels few-flowered, simple or somewhat compound; involucre large, with two or three leaflets, which are often connate at the base. On wet gravelly places chiefly around the springs in the Munyang Mountains. at an altitude from 5000 to 6000 feet. Pozoa; Lagasca. (Sect. Schizeilema, J. Hooker.) 12. Pozoa fragosea. (Fragosa hydrocotylea, Ferd. Mueller, Coll.) Glabrous; rhizome thick, creeping, with numerous long fibres; stems very short, prostrate; leaves herbaceous, long- petiolate, orbicular-reniform, net-veined, divided scarcely to the middle into five to nine crenulate lobes; stipules broad, membranous, torn; umbels sessile on the base of the petiole, or pedunculate, capitate, generally many-flowered; leaflets of the involucre five to eight, connate, lanceolate, with a few setaceous lobes; teeth of the calyx deltoid-ovate, somewhat acuminate, nearly acute ; petals greenish; carpels ovate, com- pressed on the back, with five hardly prominent ribs, strongly contracted at the axis. Under the shade of rocks on the highest tops of the Munyang Mountains, but of rare occurrence; 6000 feet. I assigned to this plant a place in the genus Pozoa, on account of the great resemblance with Pozoa reniformis, P. New Alpine Plants. 103 Ranunculus and P. trifoliata, but cannot surpress my opinion, that Pozoa and Azorella, rank only as groups of one large and polymorphous genus, namely Fragosa. (Sect. Sphagnosciadium. ) Umbels few flowered, paniculate; leaflets of the involucre few or reduced to one; flowers hermaphrodite; teeths of the calyx deciduous. 13. Pozoa cunetfolia. Sphagnosciadium cuneifolium, Ferd. Mueller coll. Glabrous; rhizome, thick; stems erect; leaves all radical, cuneate, tapering into a long petiole, three-nine nerved, in front with three-nine acute teeth or laciniz; bracteoles lan- ceolate-subulate, entire; generally equal in number to the flowers of the umbels; flowers pedicellate, sometimes solitary; teeths of calyx small, nearly acute; petals white; fruit ovate, with a retuse base; carpels slightly compressed at the back, strongly five-ribbed. At Mount Wellington, the Cobboras Mountains, and other localities of the Australian Alps, always in turf moss, (5,000 feet. a not without hesitation that I referred this plant to Pozoa, differing from the rest so decidedly in its infloresence, yet hardly in other respects. ; Gingidium ; Forster. Anisotome; J. Hooker, not of Entomologists. Calosciadium, Endlicher. 14. Gingidium glaciale. Diceceous; stem robust; leaves rigid, in outline almost ovate, bi- or tripinnated; segments hardly spreading, broad- linear, undivided, acute, mucronate, streaked, as well the rachis channelled and traversely articulated; umbels, many- rayed; carpels equal, semiterete. In the higher regions of the Australian Alps, not rare, (5-7,000 feet). The strange rigid foliage attracts the notice of all travellers which yet penetrated into this mountain. 104 Descriptive Characters of 15. Gingidium simplicifolium. Diceceous; leaves rigid, undivided, elongate-linear, articu- lated, perfectly blunt, somewhat channelled; lower umbels, few-rayed, supported by an undivided large vaginated leaf. In moist, grassy, subalpine meadows, from Mount Welling- ton to the Munyang Mountains. It is certainly very singular that the species of anisotome or gingidium shonld be all endemic. Their striking feature is highly developed by gigantic species in Campbell’s and Auckland’s Islands, reappears by numerous distinct forms in New Zealand, but is wanting in Tasmania. 16. Seseli Harveyanum. (Sect. Huseseli. ) Glabrous; stems several, erect, herbaceous, simple, from a perennial root; petioles of the stem with an ample vagina; radical leaves pinnatisected; upper segments lanceolate- or broad-linear, undivided, gradually pointed; the lower ones to the middle or nearly to the base two- or three-cleft or again pinnatisected; leaves of the stem simply pinnatisected or undivided; umbel with 4-8 unequal angulate glabrous rays and with a solitary or without a bract; bracteoles 1-3, linear- setaceous, unmargined, sometimes wanting; fruit glabrous, oblong, somewhat compressed, with sharp prominent ribs and solitary vittae in the interstices. In alpine and subalpine meadows from the Cobboras to the Munyang Mountains (4-5000’). Not dissimilar to Seseli Pallasii from Russia, offering with the following plant a new and unexpected connecting link between the Australian plants and those of northern countries since the genus was very scantily hitherto represented in the southern hemisphere, and quite unknown in Australia. The whole plant is of sweetish aromatic taste, reminding of Fennel and Garden Chervil, and might, I think, be cultivated to ad- vantage. 17. Seselt algens. (Sect. Huseseli.) Glabrous, glaucous; stems several, generally decumbent; herbaceous, simple, from a perennial root; petioles with an ample vagina; radical leaves simply pinnatisected; segments New Alpine Plants. 105 trapezoid, trifid, or the upper ones cuneate, all in front deeply and acutely toothed, often laciniated; leaves of the stem from one to three, pinnatisected; rays of the umbel 4-5, unequal, furrowed, glabrous; bracts 1-3, bracteoles several, both setaceous; fruit glabrous, truncate-ovate, with very prominent ribs. On the gravelly borders of alpine rivulets and springs in the Munyang Mountains (5-6000’). The want of ripe fruit of this plant leaves some doubt about its true generic position. It is unquestionably allied to Seseli Harveyanum. COMPOSITAE. 18. Erigeron conyzoides. Perennial, smooth, somewhat glabrous; stem erect, herba- ceous, leafy, below simple; lower leaves lanceolate, tri-nerved, tapering into a long petiole, remotely and sharply serrulate; upper ones broad-linear, acute, quite entire, sessile; flowér- heads panicled, hemispherical or campanulate; scales of the involucre linear—subulate, somewhat scabrous on the back; female flowers extremely narrow, whitish, flat, little longer than the disk; achenes compressed, oblong, scantily hairy, hardly half as long as the pappus. On the sources of the Murray and Snowy Rivers, (4000 to 5000 feet.) 19. Trineuron nivigenum. Leaves linear, blunt, indistinctly three or five-nerved, on a clasping fimbriate petiole; heads many-flowered; scales of the involucre fourteen to sixteen, oblong, with three pellucid nerves; female flowers three-or four-toothed; their style very short bi-lobed ; style of the sterile flowers undivided; achenes indistinctly tetragonous, oblong—cuneate, with but slightly thickened angules. On grassy or gravelly places in the Munyang Mountains, irrigated by the melting glaciers, (5000 to 6000 feet.) Intermediate between T. spathulatum from the Antarctic Islands, and T. pusillum from New Zealand. 20. Antennaria uniceps. Depressed, rooting, densely foliate; leaves subcoriaceous, L 106 Descriptive Characters of somewhat rigid, channelled-linear, acute mucronulate, gla- brous; petioles clasping, scarious, woolly fringed; flowerheads solitary, almost sessile; scales of the involucre glabrous, somewhat red, at the base green, the outer ones ovate, inner ones narrow-lanceolate, not radiating; pappus of the sterile flower-heads scabrous, very slightly thickened at the apex. On gravelly places near springs, or such as are subject to nundations in the Munyang Mountains, (5000 to 6000 feet.) A small tufted herb, somewhat resembling the Raoulia tenuicaulis. The fertile flowers are yet unknown. EPACRIDEAE. 21. Decaspora Clarkei. Stems short, diffused; branchlets slightly downy; leaves thinly coriaceous, flat, oblong-lanceolate, acutish, three or five-nerved, without a mucro, very much longer than the petiole, in front scabrous; spikes few-flowered, corymbose, as long as or longer than the leaves; faux of the large corolla bearded. In shady ravines at Mount Wellington, half buried in decaying leaves; very rare. This elegant little shrub bears the name of Capt. Andrew Clarke, the worthy President of the Philosophical Society, to whom the author is under many-fold great obligation, for promoting his researches. The four other species, are endemic Tasmanian ones. The large bleuish berries of this are eatable. 22. Leucopogon Maccraer. (Sect. Brachystachys.) Tall, much branched ; branchlets very little spreading, firm, velvety ; leaves spreading, ovate, or from a round base lance- olate, stalked, flat, not mucronate, glabrous, above shining in front ciliolate; spikes terminal or below the apex, few- flowered, soon erect; calyx and bracteoles blunt, ciliolated ; tube of the corolla hardly longer than the calyx; anthers half exserted; style glabrous, enclosed; drupe globose, red, generally four-celled, nearly dry. In vallies on the sources of the Mitta Mitta, near Mount Hotham and Mount La Trobe, as also along the torrents of the Cobboras Mountains. (5—6,000 feet.) New Alpine Plants. 107 This fine species is dedicated to Andrew M‘Crae, Esq., as an acknowledgment for much support received from him in my travels. ScROPHULARINAE. 23. Euphrasia alsa. Dwarf, annual; glandulously downy ; leaves sessile, in out- line ovate-cuneate, laciniate or pinnatifid ; lobes of the leaves oblong or linear, blunt; spikes very short, few-flowered ; calyx tubulose-campanulate, the lobes blunt, about as long as the tube; tube of the corolla hardly exserted, of equal length with the limb; the lobes of the lower lip emarginate, of the upper retuse ; anthers scantily bearded, the cells of all short and equally spurred; capsule orbicular-ovate, in front densely ciliated, inclosed, much compressed, few-seeded. Gregarious on the highest stoney summits of the Munyang Mountains—(6,000 feet). It differs by its annual root from all other Australian and Tasmanian species, by almost equally spurred anthers from the European, by the bearded anthers from the South American, and respectively by the same characters from the New Zealandian species. EH. Antarctica and revoluta are nearest to it related. 24. Pederota densifolia. Stems procumbent, cespitose ; leaves thick, perfectly entire, cymbiform-ovate, ciliolate, sessile ,densely imbricated in four rows; flowers bibracteate, axillary and terminal, solitary, sessile; corolla twice as long as the calyx, glabrous, pink, their tube inside unbearded ; capsule obcordate ; seeds oblique ovate, convex at the back. On the highest rocky summits of the Munyang Mountains (6—6,500 feet). A most remarkable herb, variable in the number of divisions of the corolla, and in their form. Since it does not agree in habit with the European species, it may become the type of a new genus (Cymbophyllum). PROTEACEAE. 25. Grevillea Victoria. (Sect. Calothyrsus.) Tall; leaves sub-coriaceous, undivided, long-lanceolate, 108 Descriptive Characters of rarely ovate, acute, short-mucronate, gradually tapering into the petiole, penninerved, veined, with slightly recurved margin, above smooth, beneath with branchlets and rachis grey-silky; racemes pedunculate, axillary and terminal, elongate, sometimes divided, drooping, their development centripetal; calyces three times longer than the pedicel ; outside rutilous, silky; inside, below the middle, white- bearded; style long-exserted, glabrous or scantily hairy at the extremity; germen-stalked, glabrous; stigma sublateral, ovate, slightly umbonate; follicle ellipsoidal, thinly ribbed, glabrous. Along the waters of the Buffalo Range, on the summits of Mount Buller and Mount Tambo, on the sources of the Mitta Mitta, at Mount Hotham and Mount Latrobe. A truly majestic plant, when, by descending into the vallies, it assumes a height of twelve feet and more. In higher altitudes it becomes a dwarfer bush, with shorter, almost ovate leaves. 26. Orites lancifelia. (Sect. Acroderris.) ‘ Leaves oblong-lanceolate, flat, glabrous, blunt, net-veined, perfectly entire; spikes axillary and terminal, sub-solitary ; calyx smooth; germen silky-downy, follicle silky. On the rocky summits of the the Australian Alps (5-6,000 feet high), for instance on Mount Wellington, MountHotham, Mount Latrobe, in the Munyang Mountains, in the upper valleys of the Mitta Mitta, &c. This fine shrub is besides Grevillea Victoria the only real alpine species of this natural order indigenous to the Austra- lian continent. But I am uncertain whether it may prove to be identical with O. Milligani, of which hitherto no description has been given. CYPEROIDEAE. 27. Scirpus polystachyus. Stems tall, trigonous, foliate, glabrous; leaves flat, on the keel and margins scabrous; cyme terminal, many times com- pound, little shorter than the three or five bracts of the invo- lucre; spikelets ovate-oblong, partially solitary stalked, par- New Alpine Plants. 109 tially glomerate; bracteoles somewhat keeled, lanceolate- ovate, awnless, naked on the margin, blackish-green and some- what scabrous at the back; style trifid; caryopsis roundish- ovate, plano-convex, slightly angulate at the back, short-mu- cronate, pallid, even; hypogynous bristles at the top puberu- lous, variously curved, much longer than the fruit. Along the rivulets and streams of the lower part of the Australian Alps; for instance, at Mount Linster, Omeo, and Gibbo Creek, Snowy River, &c. Spikelets of the size of Scirpus radicans, between which species and §. silvaticus it seems intermediate. I add here the only new species of Scirpus, with which I am acquainted, although not alpine. 28. Scirpus leptocarpus. Dwarf, annual; root fibrous; stems numerous, slender angulate, streaked, one-leaved at the base; spikelets one- three, spuriously lateral, ovate, sessile, many-flowered; one bract of the involucre elongate, erect, at last horizontal; the other of the length of the spikelet; bracteoles oblong, acu- minate, slightly reourved at the apex, straw-yellow, with brownish margin and green keel; style trifid; caryopsis trigo- no-cylindrical, fine dotted; hypogynous bristles white, slightly scabrous. On moist or sometimes inundated localities on the Murray, Ovens, and King, Rivers. 29. Oreobolus distichus. Leaves long, distichous, laxly imbricating, somewhat spreading, incurved, channelled, subulate, flat towards the summit, dilated and equitant at the base, serrulate-scabrous on the margin; peduncles angulate, furrowed, at last tereti- compressed ; bracteoles two or three, large, unequal; scales of the perigynium lanceolate, acuminate ; caryopsis even, ovate, acuminate. In peat-moss on the highest summits of the Australian Alps. Allied to Oreobolus pectinatus. The present species must be considered as an interesting addition to the genus. For a long time Oreobolus Pumilio, originally from Tasmania, now also observed in the Australian Alps, remained the only species. Gaudichaud added Oreo- bolus obtusangulus from the Hermite and Falkland Islands, 110 Descriptive Characters of and J. Hooker Oreobolus pectinatus from Lord Auckland’s Group, Campbell’s Island and New Zealand. Thus, it ap- pears, that all these islands possess only an isolated represen- tant of the genus. 30. Carex Polyantha. Tall; leaves broad-linear, nearly flat, keeled, with the erect triquetrous stem a little scabrous ; male spikes 4—5, elongate- cylindrical, the lowest ramified by several short ones; female spikes 3—5, very long, cylindrical, the lowest long peduncu- late with remote flowers at the base ; lower bracts very long foliaceous, auriculate but not vaginate at the base; stigmas two; fruit brown, ovate, sessile, glabrous, dotted, on both sides convex and distinctly streaked, abruptly terminated into a very short bidentate beak, as long as the lanceolate-subu- late black bracteoles; caryopsis compressed, round-oyate, straw-yellow, shining, even. In the vallies of the Upper Mitta Mitta, near Mount Hotham. More allied to Carex acuta and paludosa, than to any of the Australian, Antarctic and New Zealandian species. 31. Carex cephatotes. (Sect. Psyllophora.) Dwarf; root fibrous; leaves narrow-linear, channelled, scabrid, as long as the smooth thin triquetrous stem; spike terminal, solitary, androgynous, dense-flowered, roundish- ovate, generally bractless, with male flowers at the summit; stigmas two; fruit spreading, lanceolote-ovate, very short stalked, terminated by a short undivided beak, nerveless, even, green with black-brown tip, slightly convex at the back, longer than the brown ovate acute persistent one-nerved bracteoles; basal arista wanting; caryopsis round-oyate, tapering into the base, brownish-yellow, even, shining. i On the grassy summits of the Munyang Mountains, mois- tened by the perpetual glaciers, or on the most elevated springs. One of the handsomest species of a large cosmopolitan genus, allied to Carex capitata, from Kuropean and Asiatic Alps. New Alpine Plants. 111 32. Carpha nivicola. Rhizome creeping; stem very short, smooth; leaves and lower bracts broad-linear, blunt, with scabrous margin, flat towards the summit; spikelets one-flowered, fasciculate, greatly surpassed in length by the leaves; scales of the spikelets generally five, unequal, the outer ones twice or three times shorter than the rest; the innermost solitary, linear-setaceous, teethless, or wanting; bristles of the perigynium six, nearly to the top plumose, three times longer than the caryopsis ; stamens three; style filiform, puberulous; stigmas three, capillary ; caryopsis oblong-triangular. On the highest summits of the Australian Alps, near swamps. Closely allied to C. alpina. As a genus, I consider carpha as near allied to oreobolus as to cyathochate, rhynchospora or cheetospora. GRAMINEAE. Most of our new Alpine grasses are already published, but IT avail myself of this opportunity to bring a kind of Ehrharta under notice, singular for its incomplete flowers. 33. Ehrharta uniglumis. (Sect. Tetrarrhena.) Stems branched, with the vagine and leaves scabrous, otherwise smooth; spikelets glabrous, distinct, perinath nerved, blunt; gimmella of the lower sterile flower a little longer than the solitary gluma, and as long as the hermaprod- ite flower. In humid valleys on the Brodribb River. It bears the greatest resemblance to Ehrharta (Tetrarrhena) contexta, but differs from this in the equal length of the ste- rile flowers, and like from all others in the want of the outer glume. Art. XII.—On the Failure of the Yan Yean Reservoir. Embracing an Examination of the Report of the Committee on the Yan Yean Scheme. By Davip E. WILKIE. Esq, M.D. WHETHER we regard the magnitude of the works now in progress at Yan Yean, for the supply of the City of Mel- 112 Failure of the Yan Yean Reservoir. bourne with water, or the great importance of the interests involved in the probable success or failure of this under- taking, the subject, I think, is one which merits the atten- tion of the members of the Philosophical Society. The gravitation system has, of late years, been very much adopted wherever it has been found practicable; because, although the first cost may be great, it possesses the advan- tage of a constant supply of water, at a high pressure, and at a comparatively small annual expenditure. It becomes a matter of important calculation, therefore, in every case, to determine whether it is better, in a pecuniary point of view, to obtain river water in the immediate neigh- bourhood of a town by steam power, or to bring it from a distant and higher level by gravitation. Accordingly, about six years ago, the late Mr. Blackburn, at that time City Surveyor, directed his attention to the problem of procuring water for the city by gravitation, and. it is to that gentleman that we are indebted for pointing out the natural adaptation of Yan Yean for a large re- servolr. | In recommending his favourite scheme to the public, there is no doubt that Mr. Blackburn had satisfied himself that there would be an ample supply of water for the re- servoir. In his calculations, however, he placed great de- pendence on the natural advantages of the Yan Yean basin, in supplying a large supplemental amount of water from surface drainage, and in storing the flood water of the Plenty, independently of its ordinary discharge. He also calculated that his gravitation scheme in 1851 would cost, including distribution pipes for the city, only 84,7002. to supply a population of 70,000, at 40 gallons per head per day; while the lowest cost for supplying the same population at the same rate by steam power, from the Yarra, he estimated at 76,7002. The annual current ex- penses attending the gravitation scheme, he estimated at 858/., against 3,8942, as the expenses attending the pumping scheme. i It must be regarded as a singular fact in the history of Melbourne, that with the river Yarra so easy of access, and so peculiarly adapted by nature to furnish an un- limited supply of the purest water, no steps were taken to supply this large city until February, 1853. At that date, four Commissioners of Sewerage and Water Supply, were appointed under an Act of Council, and their Failure of the Yan Yean Reservoir. 113 engineer having reported very favourably of Mr. Blackburn’s gravitation scheme, and having condemned all other plans for supplying the city from the Yarra, they determined forthwith to commence the works at Yan Yean. I have always regretted the step taken by the Commis- sioners in adopting the Yan Yean scheme. In the month of February, last year, I published a letter for the purpose of vindicating Professor Smith’s preference of the Yarra scheme, and I endeavored to show that the Yarra water was necessarily purer than the Plenty water, and that the latter would be very much deteriorated by beg transferred into the Yan Yean swamp, and, being there de- prived of that constant and continuous motion which is its very life, that it would become incurably infected with microscopic animal and vegetable productions, which no filtration could remedy. I described the plan adopted by the city of Edinburgh, which obtains its supply direct from the Crawley Springs, without subjecting the water to the injurious influences of exposure in a large open reservoir. And I urged the great advantage of possessing an unlimited supply of this necessary of life which the Plenty could not afford; and, as objections had been taken to all other Yarra schemes, on the ground of their impracticability, and the annual expenses attending them, I ventured to propose a simple scheme for bringing the Yarra water into Melbourne, on the gravitation principle, by means of a tunnel carried to the base of a shaft to be sunk alongside the Eastern Hill reservoir; which would thus have the effect of diminishing as far as possible the expense of pumping and management; and I showed that the annual expense of a pumping scheme for 100,000 inhabitants would cost a half-penny per week, per head; and that any expense was of trifling importance when the health and comfort of a populous city were involved. . I regret that I did not further prosecute my inquiries at that time, but the truth is that my letter having received no attention or sympathy in any quarter, I saw no prospect of ee off the evil which I believed to be impending over the city. - I still object to the Yan Yean scheme—1l. Because of the enormous expense. In consequence of the discovery of the Gold-fields, labor is now at a much higher rate than when it was first projected by Mr. Blackburn. The Commissioners’ estimate for the works is £650,000, of which £400,000 have M 114 Failure of the Yan Yean Reservoir. already been expended; but it is the opinion of many that they will more probably cost £1,000,000. 2. Because the Commissioners, in erecting temporary works for supplying the city from the Yarra, have shown that, for the comparatively small sum of £30,000, the same object can, to a certain ex- tent, be accomplished; and, indeed, if they had erected their temporary works at the right place, viz., near the junction of the Merri Creek with the Yarra, about a mile and a half from the reservoir at St. Peter’s Church, the temporary works being distant half a mile from the same reservoir, and, so as to have avoided the surface drainage and sewerage of Collingwood and Richmond, we could have dispensed with the Yan Yean Water Worksaltogether. The expense of the additional horse-power required for the increased distance of one mile, which would be about six horses added to forty, and the saving in the carriage of coal, are trifling advantages to be purchased at a sacrifice of the public health, in a popu- lous and wealthy city, which this measure really involves, as it has been clearly shown, by chemical analysis, that the wa- ter at Prince’s Bridge contains four times more of impurities and matters prejudicial to health than the water at the junc- tion of the Merri Creek with the Yarra. But let us suppose that it would have been necessary to expend £60,000 in the erection of permanent works for raising water from the Yarra into the reservoir at St. Peter's Church, this would have been decidedly preferable as a com- mercial enterprise, when we contrast the interest of £60,000 at 10 per cent. with that of £600,000. The Commissioners have thus altogether sacrificed the pe- cuniary interests of the public in their selection of the gravi- tation scheme, and have ignored the principle upon which a selection of either scheme is always based, namely, its adapt- ation to afford an ample supply of water at the lowest possi- ble cost. 3. I object to the Commissioners’ scheme because I do not think that in this climate a large swamp covering 7,000,000 square yards of surface is a suitable place for storing water for the consumption of a large city. It has been the natural receptacle for the surface drainage of the surrounding ranges, - with only a very small natural outlet or water course. The consequence has been a vast accumulation of green slimy mud, the result of decaying organic matters, which will greatly alter and deteriorate the water of the Plenty, which, within its own banks, is exceedingly pure. And I find, on Failure of the Yan Yean Reservoir. 115 referring to the able report of the Select Committee of the Legislative Council on Sewerage and Water Supply, that those gentlemen who were best qualified to give an opinion on the subject were unanimous in describing the deterioration which the water would undergo by being stored in the Yan Yean reservoir. The language used by one physician was that the water would be almost incurably contaminated; by another, that he should not like to use the water himself. As regards the purity of the water, therefore, I think the Commissioners have disregarded the best interests of the pub- lic in a sanitary point of view. 4. I object to the choice of the Commissioners, because it was based on insufficient data. The Select Committee, in their report, say “our meteorological experience in these colonies by no means justifies the sanguine anticipations of Mr. Blackburn, who himself admits that a continued drought for two years, or even eight months, would render the whole scheme a failure;” and they state the following very grave ob- jections to the reservoir scheme. 1. “That it would seem to be against all experience that any of the sources of the Plenty should be constant in all seasons. 2. “That sufficient allowance has not been made for the ef- fect of evaporation over so large a surface as 1,200 acres, the proposed superficies of the reservoir.” And, while they were of opinion that the advantages upon the whole preponderated in favor of the gravitation scheme, they preferred to adopt the eourse taken by Mr. Hodgkinson in his evidence, and declined giving a positive opinion on the subject. It is difficult to see what peculiar advantages the Select Committee had in view, without referring to the estimates of the two rival schemes which they were contrasting. The ad- - vantages which one scheme of water supply possesses over an- other, are always reducible to a money value. The following are the estimates for the two schemes, which were under the consideration of the Select Committee in January, 1853. First Cost. Annual Expense. Modified Gravitation Scheme £162,713 £1,450 Mr. Hodgkinson’s Yarra Scheme 99,689 7,600 The objections which, in the opinion of the Select Com- mittee, applied to Mr. Hodgkinson’s plan, had reference exclusively to the annual expenditure for coal and supervision, 116 Failure of the Yan Yean Reservoir. amounting to £7,600. A singular objection, when it was admitted that the people of Melbourne had hitherto been compelled to pay at the rate of £150,000 a year for a miserable supply of water—£10,000 a year for a population of 100,000 is a halfpenny per week for each individual. If we add to this £10,000 as interest for the first cost of Mr. Hodgkinson’s scheme, the cost of an efficient water supply from the Yarra, with all the advantages of purity, certainty, and high service, would have been a penny a week per head. Tt is a singular fact, and worthy of being recorded, that the raigdlil eravitation scheme, under the patronage of the Commissioners 's, SO expanded itself in less than twelve months, as to re-appear under the new estimate of £650,000. A good deal has been said of the advantages that the Yan Yean scheme possesses over its rival in its powers of indefinite extension. Perhaps this remarkable increase in the estimated cost is to be regarded as an illustration of this principle. 4, My chief objection to the Yan Yean scheme is the very limited supply of water for so colossal an undertaking, and this serious objection did not escape the notice of the Select Committee, who admit that it is “accompanied with the drawbacks that the quality and quantity of water might by possibility fall short of the standard, and that in the execution of the work some unforeseen difficulties might have to be encountered.” And the chief object of this paper is to place before you certain data by which you may be enabled to judge for yourselves on this all-important point. Having long entertained the opinion that the Plenty, from its limited size, was quite unsuited to supply the city with water, I resolved, in December last, to visit the Yan Yean Water Works, and obtain all the information I could respect- ing them. Andas Dr. Mackenna had expressed himself much interested in the result of my inquiries, I invited him to accompany me, which he very kindly did. Mr. Taylor, the resident overseer of the works, aclatel showed us every attention, and gave us every information we desired. It is proper “here to mention, that when I submitted my first paper to you last month, it was necessarily based upon very limited data; but I was so impressed with the import- ance of the subject, and the result of my own inquiries, that I suggested the appointment of a Committee for the purpose of investigating the whole subject in a scientific manner, and reporting ‘to the Society. I should also add, that I had the honour of accompanying your Committee on their scientific Failure of the Yan Yean Reservoir. 117 tour, and'I shall not soon forget the pleasure and instruction it afforded me, and through their kindness in furnishing me with their measurements and calculations, I am enabled to submit to you this evening my opinions on the Yan Yean reservoir scheme, based on more correct data, and more exten- Sive inquiry. There is a considerable discrepancy in the published accounts of the amount of water consumed by different cities. It appears that London and some other cities in England are supplied with 30 gallons per head per day, Glasgow is supplied with 30 gallons per head, by steam-power, Notting- ham consumes 40 gallons per head, and the Croton aqueduct at New York is calculated to discharge 60,000,000 gallons in 24 hours, which for a population of 500,000 gives 120 gallons per head. Great credit is due to the City Council for haying from the first laid it down asa settled principle that Melbourne should be supplied at the rate of 40 gallons per head. At the same time I cannot regard this amount as adequate in a sanitary point of view to our actual requirements. Melbourne and New York are in similar latitudes, and considering the hot winds and dust storms, and the very dry atmosphere and long droughts that are peculiar to Australia, a more liberal supply of water would be required here than in New York. For public baths and fountains, for thoroughly watering the streets, cleansing the gutters, and flushing the sewers, for extinguishing fires, and limiting their rapid and destructive progress, the water supply of this city should not be measured by so many gallons per head, the supply should at all times and under all circumstances be amply sufficient for any increased or unforeseen demand that might arise; but it will be shown in this inquiry that there is no such ample supply at Yan Yean to satisfy such luxurious anticipations, and we must be contented to limit our wants to the supply we can command. And in the event of a drought, to use the words of the Select Committee, “it is incontestible, that the most careful provisions would be necessary to guard against any unnecessary waste of water.” I shall, therefore, assume forty gallons per head as the amount that it will be necessary to provide for this city; and this is the amount upon which Mr. Blackburn and Mr. Hodg- kinson based all their calculations, in their evidence before the Select Committee. There is one important point in which I must differ from the Select Committee, and that is in limiting the amount of 118 Failure of the Yan Yean Reservoir. population to be provided for. Mr. Blackburn declined giving an opinion on this head, and I think the Select Com- mittee were wrong in limiting the number to 100,000 for the modified gravitation scheme that was to cost 162,0002, but they are in no way identified with the more costly scheme of the Commissioners. A gravitation scheme, involving an outlay of 650,0002. of public money should not be limited to any amount of population short of 500,000. In other words, it should not be commenced at all until an ample supply of water for 500,000 be secured. The population of Melbourne, with its suburban towns and villages, is little short of 100,000; and the amount required for this number, at the rate of 40 gallons per head, per day, would be equal to 8,690,476 cubic yards. Now, as the area of the reservoir is 7,000,000 square yards, this amount of water would give a depth of 3 feet 8 inches in the reservoir, and a population of 500,000 would require a depth of 18 feet 4 inches. Let us now inquire what amount of water can be supplied to the reservoir. The main feature of the Yan Yean scheme is the large reservoir, or natural basin, which has an area of about 1450 acres, and a surface of about 7,000,000 square yards, and into which it is intended to direct the greater part, if not the whole of the watershed of the Plenty basin. For this purpose an aqueduct of about two miles in length is being now formed to lead the river into the reservoir, and a large embankment is being raised at the lower end to the height of thirty feet; and, as it is expected that the river will more than fill the reservoir, and that it will maintain a current through it, there is a waste wash at the height of twenty-five feet to lead back the surplus water to the Plenty. A tower well has also been erected within the embankment, and is so arranged as to admit the water into the main pipes by two openings, at ten and seventeen feet, from the bottom of the reservoir. The third opening at the bottom of the tower well, as explained by Mr. Taylor, is only intended to draw off the impurities that will be deposited from the water. The Plenty takes its risein Mount Disappointment by two main branches, the eastern and the western. The latter, according to Mr. Hodgkinson, takes its source from a con- siderable stream which gushes direct from a fissure in the granite. The eastern branch, as we had lately an opportunity of witnessing, takes its rise from the table land at the very top of the mountain, and, from the smallest possible begin- Failure of the Yan Yean Reservoir. 119 ning, is gradually augmented by innumerable rills and streams issuing from the moist rotten soil and from the fissures and crevices of the rocks. Both branches, at the base of the mountain are discharged into large swamps; and it is not until they issue again from these that they unite to form the Plenty River, about four miles from Yan Yean. The area of the western swamp, according to the estimates of your Com- mittee, is 787,000 square yards, that of the eastern, 3,808,000 square yards. These streams have been measured at different times and under different circumstances, with the following results. The late Mr. Blackburn, in his first report on the water supply of Melbourne, dated 9th January, 1851, states that he had measured two of the branches of the Plenty, above the marshes, and found them to discharge respectively 2,000 and 1,700 gallons per minute, and he estimated that the whole discharge of the tributaries amounted to 5,000 gallons per minute, which is equal to 6 feet 7 inches in the reservoir, while the united stream below the marshes scarcely gave 2,700 gallons per minute, or 3 feet 7 inches. There was thusa loss by evaporation of 2,300 gallons per minute, which would give 3 feet in the reservoir, in twelve months. There being an unusual drought in the summer of 1851, Mr. Blackburn, on two separate occasions, revised his former measurements ; on the latter occasion, the 14th February, he found the discharge of all streams above the swamps amount to 4,040 gallons per minute, which equals 5 feet 4 inches in the reservoir, and in the river below the swamps he found only 865 gallons per minute, or at the rate of 1 foot 1 inch in the reservoir, showing a loss by evaporation of 3,175 gallons per minute, which would give 4 feet 14 inch in the reservoir. Mr. Hodgkinson, on the 9th December, 1852, after fifteen hours’ rain, measured the western arm, where it issues from the granite rock, and estimated the discharge at 1,180 gallons per minute, or 1 foot 7 inches in the reservoir; he also measured the same stream, where it enters the swamps, and found it to give 1,700 gallons per minute, or 2 feet 3 inches. On the following day he measured the eastern arm, below the first waterfall, and found it to discharge 1,980 gallons per minute, or at the rate of 2 feet 74 inches in the reservoir. The first of Mr. Hodgkinson’s measurements is the one of most value in this inquiry, as we may presume that the stream, where it issued from the rocks, was little affected by the previous rain. The second measurement was taken at a 120 Failure of the Yan Yean Reservoir. situation where it could not fail to be considerably augmented by the rainfall of fifteen hours. The measurement of the eastern arm, which was obtained the following day, could not give any certain result, as it was taken above the junction of three small tributaries. In one point of view, however, it is very important, as the object of the measurement was to illustrate the constancy of the supply. All the other tribu- taries of the Plenty have been known to fail on several occasions. The measurement of the main eastern branch, therefore, shows an approximation to the amount of water supply that would be available above the swamps in a severe drought, but it is only an approximation, as it too may also fail; there is certainly no guarantee in the height of Mount Disappointment, which is only 1,500 feet, to warrant a more favourable opinion. All the tributaries of the Plenty equally depend on the rainfall of the mountain ranges, and it is simply because the main eastern branch rises from the highest point, where there is most rain and least evaporation, that it holds out the longest when the ordinary supply of rain is cut off. I come now to mention the measurements which were made by the Committee who were appointed to investigate this subject at the last meeting of the society. The river, at its junction with the aqueduct, with a velo- city of half a mile an hour, gave a discharge of 2,537 gal- lons per minute, or an equivalent to three feet four inches in the reservoir. The eastern arm above the swamps yielded 4,450 gallons per minute, or an equivalent to five feet eleven inches. If we take Mr. Hodgkinson’s measure- ment of the western arm, where it issues from the rocks, namely, 1,180 gallons per minute, and add to it the Com- mittee’s measurement of the eastern arm, we shall have 5,630 gallons as the discharge of all the streams above the swamps; and if we take into consideration that one week before their visit to Yan Yean there were nearly three days of heavy rain, which is an unprecedented occurrence in January, the 630 gallons may be regarded as due to this source, and the balance of 5,000 gallons per minute will exactly correspond with Mr. Blackburn’s estimate. From these measurements, it would also appear that the eastern arm bears the proportion to the western arm of 4,450 to 1,180, or very nearly four to one. By this estimate we shall find that the discharge of the western arm was 1,340 Failure of the Yan Yean Reservoir. . 121 gallons per minute, at the time when the committee measured the eastern arm. The whole discharge above the swamps was therefore 5,790 gallons per minute, and below the swamps 2,537 gallons. In this manner we ascertain that the loss by evaporation in the swamps amounted to 3,253 gallons per minute, which is at the rate of 4 feet 4 inches in the reservoir; and as the area of the swamps is one half less than the area of the reservoir, 8 feet 8 inches will represent the rate of evapora- tion in the swamps during the summer months. It is thus easy to understand why Mr. Blackburn and Mr. Hodgkinson so strongly urged the necessity of making arti- ficial watercourses, in order to withdraw the two branches of the river from the influence of the swamps. It does not appear that the Commissioners of Sewerage and Water Supply have any present intention of doing this, and I am not sufficiently acquainted with the levels and depths of the swamps to give any opinion as to the best mode, but it is quite clear that some steps must be taken to save the immense loss that is at present occasioned by them. And in estimating the quantity of water that will be available for the reservoir I shall assume that some effectual means will be adopted to accomplish this very desirable object, and that the whole of the 5,000 gallons may be transferred into the reser- voir without loss. The measurements would not be complete without men- tioning, that Dr. Mackenna and myself, on our visit to Yan Yean, measured the Plenty where it passes under the bridge, about three miles below the reservoir, and obtained a discharge of 960 gallons per minute, which would give a depth in the reservoir of 1 foot 3 inches. The measurement of the committee at the same place, on their late visit, gave 475 gallons per minute, which is equal to 8 inches in 12 months. These small results compared with the measurement above Yan Yean arise from the quantity of water that is abstracted by a cut for the purpose of puddling the embankment. I have thus assumed Mr. Blackburn’s highest estimate of 5,000 gallons per minute as the average of the whole discharge of the tributaries of the Plenty. In the drought of the summer of 1851, however, Mr. Blackburn found this amount reduced to 4,040 gallons; and therefore it is to be presumed that 5,000 gallonsare only to be depended on in ordinary seasons. The important question now arises, what proportion of the 5,000 gallons can be abstracted from the river without inflict- N 122 . Failure of the Yan Yean Reservoir. ing serious or irreparable injury upon the inhabitants of the district through which the Plenty takes its course. One witness, who was examined before the Select Committee, gravely proposed that a-half-inch pipe from the reservoir should be given to the inhabitants on the banks, in lieu of the river itself; but to be serious, I am most decidedly of opinion that it would inflict irreparable injury upon the inhabitants of the Plenty district to abstract more than two- thirds of their river from them. Even with this loss they will suffer enough in the permanent closing of all the mills ; and I have no hesitation in saying that the good sense of the ublic of Melbourne would neither expect nor demand more. If the Yan Yean scheme cannot afford to do this it had better be abandoned at once. Nor do I think that the public interests would suffer much thereby. In ordinary seasons, as already shown, the discharge of the Plenty above Yan Yean, is 2700 gallons per minute in December, and deducting one-third there will remain 1800 gal- lons, or an equivalent to 2 feet 5 inches; this, added to 2300 allons, which is the amount at present lost in the swamps, but which I take for granted will be saved, gives 4100 gallons per minute as the average amount of water available from the river for the supply of the reservoir, and this will give a depth of 5 feet 6 inches. It is more difficult to calculate the amount that might be ~ obtained from the river in time of floods, from the uncertainty of their occurrence, volume, and duration. Had the reservoir been in close proximity to the river, with a sufficient fall, a large amount of flood water might easily have been secured ; but in order to obtain 25 feet of depth for the reservoir, it is necessary to bring in the river from a higher level by means of an aqueduct of about 2 miles in length, which winds round the base of the range which separates the river from the reservoir, aud which will enter the latter by a tunnel which is being cut through this dividing range. Unless, therefore, a very strong embankment be constructed for the purpose of damming the flood water, which would be a very difficult and expensive operation, owing to the level character of the right or opposite bank, it is difficult to see how the floods can be taken advantage of to any great extent. On such occasions the water is widely extended over a large surface, and will naturally prefer the lower level of the river to the higher level of the canal or aqueduct. Assuming, however, that the aqueduct can be filled from Failure of the Yan Yean Reservoir. 123 the river in time of floods, and assuming that the Plenty will be in a flooded condition for 60 hours in each year, the sec- tional area of the aqueduct, which is 127 feet, witha velocity of one mile per hour, will give 1,494,000 cubic yards, which would add a depth of seven and a-half inches to the reservoir, or at the rate of 3 inches each day. ‘This result, however, could only be obtained with a dam, so constructed as to raise the surface of the flood water to the height of eight feet: above the present level of the river, and at the entrance of the aqueduct the right bank is only one and a-half feet above this level. In order to do every justice to the resources of the Yan Yean reservoir, I think, that during the three winter months, we may assume that the river is larger than in the summer months, during which season the above measurements have been all made; and I shall take this opportunity of urging how important it would have been to have had accurate measurements of all the tributaries of the Plenty for each month of the year. As there is one-third more rain in the winter months, I propose to allow two-thirds more watershed, independent of floods. This will be equal to one-sixth of 5,000 gallons per minute, or its equivalent, six feet seven inches, which will give an addition of one foot one inch to the reservoir. It may appear to some that I have allowed too little for floods. It may be thought that sixty hours will not accurately represent their duratiion for twelve months. It must be remembered, however, that the entrance of the aqueduct is only eight miles from the source of the eastern or main branch of the Plenty. With such a short and lmited watercourse, therefore, in a few hours after any heavy fall of rain, the river will have returned within its own banks. It must also be remembered that we may possibly have no floods at all in twelve months ; and I feel quite certain that in the last twelve months the river has not been flooded for more than twelve hours at Yan Yean. As a source of supply for the reservoir, the next in * importance is the annual fall of rain. The meteorological tables which have been kept in Melbourne for a period of six years, give thirty inches as the fall of rain for twelve months, and eighteen inches for the six winter months; but as Yan Yean is 600 feet above the level of the sea, I propose to allow six inches on that account, and, therefore, thirty-six inches or three feet, may be set down as an addition to the 124 Failure of the Yan Yean Reservoir. reservoir from this source, and in the same proportion twenty- two inches represent the rainfall for the six winter months. Having ascertained the rainfall of the Plenty basin it would be of great importance to determine the whole amount of the watershed. The only certain method of obtaining this result would be to take accurate measurements of all the tributaries, at least once in each month, and to make a careful survey of the floods that may occur during the year. In the absence of such measurements it becomes important to estimate the amount from data that are recognised in England, making due allowance for the difference in the mean temperature, and the physical peculiarities of the drainage area. If we could ascertain the amount of rain in any district, and the proportion of the rain that is evaporated from the surface of the ground, the difference would exactly equal the contents of the rivers. ; On this principle, the late Dr. Thomson, the Professor of Chemistry in the University of Glasgow, estimated the watershed of Great Britain at four inches of the rainfall. From the meteorological tables he calculated the rain, including four inches of dew at thirty-six inches, and from experiments and observations he calculated the amount of evaporation from the ground at thirty-two inches. He therefore computed the watershed at four inches, or one-ninth part of the rain. Although Dr. Thomson considered his estimate of four inches too high, from a calculation which he made of the the contents of the river Clyde, compared with its drainage area, yet it differs so greatly from other estimates, which are as high as eleven and thirteen inches, that the only inference we can draw is that the whole subject is still enveloped in so much obscurity and uncertainty, that no correct practical results can be obtained by this method. It would, therefore, be altogether a visionary speculation, to make the water supply of a large city depend upon the correctness of either of the higher estimates. It would be unworthy of modern engineering science, and could only lead to failure and disappointment. The most correct view of the subject is probably that entertained by Dr. Prout, who thinks that the truth lies somewhere between the extremes, and I therefore feel dis- posed to determine the watershed of England, in accordance with the experiments of Messrs. Hoyle and Dalton, who Failure of the Yan Yean Reservoir. 125 found, with a mean rain of 33.55 inches for three years, that the evaporation from the ground equalled 25:14 inches; therefore 8°41 inches, or one-fourth of the rain, may be presumed as the amount available for springs and rivers in England. lam not aware that any experiments have yet been con- ducted in this colony to determine the proportion of the rain that is evaporated. The physical character of the country, however, shows that there are comparatively few rivers, and that these are very scantily supplied with water, and that floods are not of frequent or regular occurrence. The absence of high moun- tains, and the arid and desert condition of the interior, while they greatly diminish the rainfall, contribute to render the atmosphere peculiarly dry, and evaporation very rapid. In the summer months many rivers and creeks are dried up, and the ground becomes so parched that it is capable of quickly absorbing a large quantity of rain, so that it is rare to find rivers much increased during this season, and the watershed is very trifling indeed. I think, therefore, that with nearly the same amount of rain as in England, and with a much smaller proportion of rivers and fewer floods, there must be a much larger propor- tion of rain evaporated from the surface. I may thus, on very strong grounds, assume that the watershed in this colony is one half less in proportion than in England, and therefore amounts very nearly to Dr. Thom- son’s estimate, which is one-ninth of the rain. But it is more satisfactory, and certainly more correct, to deduce the watershed of this colony, from that of England, by making adequate allowance for the difference in the force of evaporation due to our higher mean temperature ; and, as it is admitted by scientific men here, that the evaporation from the surface of water is nearly double that of England, it is strictly correct to assume that the proportion of rain evaporated here will also be nearly double. Thus, I think, no valid objections can be offered to my assuming four and a-half inches instead of eight and a-half, as the best approximation that can be made of the watershed of this colony, until the mean discharge of the different rivers is ascertained by actual measurement. In mountainous districts the watershed is greater in pro- portion than in the low country, and the absorption and evaporation less; and therefore it might be thought that Dr. 126 Failure of the Yan Yean Reservoir. Thomson’s estimate cannot apply to the Plenty Ranges, but their geological formation, and the tropical vegetation with which they are covered, are singularly adapted to absorb and retain a large proportion of the rain that would otherwise flow direct into the watercourses; and it is to this beneficent provision of nature in this dry climate that all the rivers that take their rise in the primary and granitic formations owe their permanency, and not to springs of the ordinary kind, that are met with in the secondary and tertiary formations, which are almost entirely absent; and were it not for this provision the river Plenty, and other similar streams, would cease to flow altogether in the summer months. The winter rain which is now stored up in the spongy soil, and in the caverns and fissures of the rock, maintains a more or less constant stream during the whole summer, and it is in this manner that we explain the otherwise singular fact, that the river Plenty is so little increased in size, during the winter months, in ordinary seasons. In my estimate of the discharge of the the river I have aliowed an increase of two-thirds. But it is not to be supposed that the water thus stored is altogether removed from the influence of evaporation. On the contrary, from its universal tendency to find a lower level it is constantly oozing out over the whole surface of the ranges, and leading gullies, which is thus always in a wet condition, and always evaporating, and the surface is so wet even near the summit, that we found abundance of small leeches several hundred yards from the stream. The watershed of the Plenty ranges, therefore, differs essentially from the watershed of ordinary mountainous country, and thus the evaporation from the ranges is, proba- bly, fully equal to that from the plains, because while eva- poration from the level country is one-third more rapid than from the ranges, it ceases nearly altogether for three months in the former, while in the latter it is constant throughout the year. The drainage area of the river above the aqueduct, ac- cording to the Survey Maps, may be computed at about sixty square miles. The ratio of this surface to the surface of the reservoir is as 26 to 1, therefore the whole rainfall, including four inches of dew, would give a depth of eighty- eight feet in the reservoir, and one-ninth part of this, or nine feet nine inches, would give the watershed. It may be interesting here to contrast the whole discharge of the Plenty, as I have already estimated it, with the Failure of the Yan Yean Reservoir. 127 whole amount of the watershed as deducible by Dr. Thom- son’s method. Ft. In. 5,000 gallons per minute - 6 7 60 hours’ floods - = 0 ve Two-thirds increase in winter months 1 1 Total - - 8 3h Whole watershed : - 9 9 Balance unaccounted for il 54 The only other important source of supply is the drainage area of the reservoir itself’ Mr. Hodgkinson was kind enough to measure this area for your committee, and his estimate is 3,000 acres, or about twice the surface of the reservoir. During the winter months there has generally been more or less water in the reservoir ; but during the summer it has almost always been quite dry. In 1851 there was no water in it during the whole year; and this fact is not only important as regards the water- shed of the reservoir, but it has a far more extensive and significant importance as regards the watershed of the Plenty. I have estimated the rainfall for the basin of the Plenty at thirty-six inches; but im 1851 there was so little rain in that district, that even during the winter months no water was collected in the reservoir, from a drainage area, including the reservoir, of nearly seven square miles, or one-eighth part of the dramage area of the Plenty. It can hardly therefore be alleged that I have under-rated the average watershed of the Plenty. After heavy rains and floods, the reservoir has sometimes had as much as two feet of water at the lower end, and then it overflows into a small watercourse or rather swamp, which skirts the ranges for about two miles, and then enters the river by a creek, which has a sectional area of about twelve feet. At the upper end, the reservoir receives a larger ereek, which has a length of about three miles, and contains a large quantity of water after heavy rains; but when there is no rain it is quite dry. According to the best information which I have received the reservoir has, on an average, been dry for six months in the year, evaporation, therefore, must be constant during 128 - Failure of the Yan Yean Reservoir. the six winter months; now from other data we can estimate the amount of water thus evaporated, which is equal to two feet five inches, and the rainfall, for the same period, is twenty-two inches, leaving a balance of seven inches to repre- sent the surface drainage that is evaporated. If the watershed, therefore, exceeds seven inches it must escape by the small creek at the lower end, and may be approximately ascertained. This watercourse has been generally observed to run after heavy rain, but not otherwise. If, therefore, we assume that there are, during the winter months forty days of heavy. rain, and that the creek is, on an average, half full, and that its velocity is about half a mile per hour, the contents would amount to 1,900,800 cubic yards, which would give seven inches in the reservoir. By this estimate the water shed cannot exceed fourteen inches. It is important, also, in this enquiry, to estimate the water= shed according to Dr. Thomson’s method. The ratio of the drainage area to the reservoir being as two to one, the whole rainfall would give a depth of six feet, and one-ninth would give a watershed of eight inches; but as there is no water- shed in the six summer months, and as the rainfall of these months is less than that of the winter months, in the propor- tion of two to three, the rainfall of the drainage area must be taken at three feet seven inches for the winter months; and as the area is chiefly composed of ranges of clay slate, which are much less favourable for absorption than the level country, three-ninths or one-third instead of one-ninth of the rainfall may be estimated as the watershed, and this will give fourteen inches, which exactly corresponds with the former estimate. I shall here notice some considerations which would seem to prove the correctness of Dr. Thomson’s estimate, in its application to the basin of the Plenty. Mr. Blackburn’s highest estimate of all the tributaries is 5,000 gallons per minute, or 6 feet 7 inches in the reservoir. One half of this amount, therefore, or 3 feet 34 inches, will represent the absolute quantity of the watershed for the six summer months. Now, as there is one-third less rain, two- fifths of 88 feet, or 33 feet in the reservoir, will represent the whole of the rainfall for this period. Therefore, the water- shed is equal to one-tenth of the rainfall, and the remaining nine-tenths are evaporated. In the six winter months there is one-third more rain, and, Failure of the Yan Yean Reservoir. 129 therefore, there will be one-third more water shed; but eva- poration is also one-third less rapid, so that if we add two- thirds to Mr. Blackburn’s estimate for the six winter months, we shall have the water shed for that period. To 3 feet 33 inches add 2 feet 23 inches, which give 5 feet 6 inches. Now, 55 feet represent the whole rainfall for the six winter months; therefore, 55 divided by 54, or one-tenth of the rain, gives the whole watershed. This result may be regarded as a near approximation in ordinary seasons, with no heavy falls of rain, but on such occasions, there is too little time for absorption, and a much larger proportion of the rainfall is quickly conveyed to the rivers. But most people have very exaggerated notions respecting floods, and many people fancy that one flood would fill the Yan Yean reservoir, if it could be secured. The following considerations will show the very small proportion of the rainfall that can be contained in any ordinary flood. The velocity of the river, at its junction with the aqueduct, is half a mile per hour, and its present discharge gives 3 feet 4 inches in 12 months; therefore, 88 feet, or the whole rain fall of one year, would require 26 years to pass down the river. The aqueduct has 94 times the sectional area of the river, yet with this volume and the same velocity, the whole rainfall would require 985 days, or more than 2} years to be conveyed into the reservoir, while such floods as would fill the aqueduct, do not last more than 2 or 3 days. The mean rainfall of the different months here is 2} inches, which can readily be disposed of by absorption and evaporation in mild seasons. The highest mean rainfall is four and one-fourth inches; and in November, 1849, there was a fall of twelve inches, in consequence of which we had a very high flood in the Yarra, which lasted about a week. -I possess no information with regard to the duration of the flood in the Plenty at Yan Yean, but with so short and h- mited a watercourse, I consider itimpossible that theriver could have been flooded at that time for more than three days. The sectional area of the highest flood line, as determined by your committee, is 200 feet. Now, with a velocity of two and one-half miles per hour, which is the velocity adopted by them, three days or seventy-two hours would give a dis- charge of 7,040,000 cubic yards, which is equal to three feet in the reservoir, or one foot per day; and such a flood as that. of November, 1849, probably does not occur more than once in ten years. ce) 130 - Failure of the Yan Yean’ Reservoir. But how could such a flood be secured for the reservoir ? The same amount of water would take twelve days to pass through the aqueduct at one mile an hour, which is the high- est velocity that it would be either safe or prudent to allow. A higher than this, in such a winding canal cut out of the clay-slate, would convert the water into mud, and break up the sides, and wash away the artificial banks; and for the sake of such a flood, which may possibly occur once in ten years, would it be reasonable to spend £30,000 in enlarging the aque- duct to four times its present size? and without suitable embankments raised at an enormous cost, to dam up such a flood, one half would not enter the aqueduct at all. As twelve inches of rain fell during the month, instead of four, we may safely conclude that this flood resulted from a rainfall of at least six inches, which would give thirteen feet in the reservoir, so that out of thirteen feet of rainfall in one of the heaviest floods on record, only three feet reach the rivers, or less than one-fourth. The only other source of supply to be noticed is dew. In England from four to five inches have been computed as the amount of dew deposited on the ground, but I am not aware of any experiments to show the amount deposited on water. I feel persuaded that the atmosphere is generally so dry here, that the amount of dew must be very small; and unless in the case of very shallow pools and lakes, there can be very little deposited on water. A depth of two or three feet will, in a great measure, prevent the formation of dew, because as the upper particles become cooled they at the same time descend, from their increased density, to make way for the warmer and lighter particles underneath, and until the whole depth of water has attained a considerably lower temperature than the atmosphere with which it is in contact, no deposition of dew can take place. As it is possible that there may be some dew, when there is very little water in the reservoir, I shall on this account allow an increase of two inches for the whole surface, which is equal to sixteen and one-half days supply for the city. The whole amount will stand thus :— From the River Plenty - - - 5ft. 6in. Floods in ditto - - = - ve Increase from winter rain - - - Rainfall in reservoir . 4 “5 a 0 i lalbatoas b 3. 6 (OO Drainage area of ditto - - - 1 2 Dew - - - - - =i OL a2, ll. 63 Total amount Failure of the Yan Yean Reservoir. 131 I come next to determine the amount of loss from evapo- ration and absorption. In large reservoirs the annual evaporation from the surface is a very important element to be considered, and, as it increases nearly in a geometrical ratio, with an arithmetical increase of temperature, a comparatively small difference in the mean temperature might give double the amount of evaporation. It is therefore especially important in warm climates that its actual amount should be ascertained by a careful series of experiments, before any work of magnitude is undertaken, whose success or failure might entirely depend on the result. - In my first paper, which I only regarded as a preliminary inquiry, 1 computed the evaporation for this colony from the tables of Dr. Dalton, who gives forty-four inches as the evaporation for England. I took the mean temperature of the different months in Melbourne, and assumed for each month the amount of evaporation corresponding to the month of the same mean temperature in England. I also estimated the increased evaporation proportionate to the increased mean temperature and to hot winds, to which I allowed a mean temperature of 87°, and a duration of fifteen days, and I thus determined the evaporation to be seventy-two inches or six feet. I stated, however, that I felt satisfied that a careful series of experiments would show a still higher result, as, independent altogether of the temperature, the much drier condition of the atmosphere in Australia exercises a powerful - influence in promoting evaporation. Since our last meeting I have ascertained that Mr. Glaisher, who is the highest authority on meteorological subjects, has estimated the evaporation at Greenwich at sixty inches, or five feet annually. Proceeding upon this higher estimate, the evaporation, calculated in the same way, would be equal to eight feet two inches; and, making due allowance for the dry condition of the atmosphere, nine feet may be safely assumed as the mean evaporation for this colony. I have also learned that Dr. Davey, a member of this Society, has devoted a great deal of attention to this subject, and he has furnished me with the result of his experiments. He is quite confident that the mean evaporation is not under nine feet, but he is inclined to believe that it is more probably ten feet. This summer having been remarkably cool, with a great deal of rain, and few hot winds, is not to be regarded as an average season. 132 Failure of the Yan Yean Reservoir. - Being anxious to ascertain the rate of evaporation over a large surface, fully exposed to the influences of the weather, I lately selected a sheet of water of about 300 yards long, with an average depth of eighteen inches, and width of four- teen feet, and, by fixing a mark in a particular part of the bank, I made careful measurements several times during fourteen days, and found that the amount lost exactly equalled six inches in that time, which gives five lines per day, and, for the three summer months, three feet two inches. The weather throughout was cool, excepting one day, and the winds southerly and easterly, so that this may be regarded as the lowest rate at this season. By computing the evapo- ration of the other months according to their mean tempera- ture, this rate would give nine feet for the twelve months. In further illustration of this subject, I may mention that Mr. Laidlaw has computed the evaporation in Calcutta at fifteen feet, and he also found that it averaged nearly three- fourths of an inch a day, between the Cape of Good Hope and Calcutta, and between 10° and 20° in the Bay of Bengal, he found it to exceed one inch daily, or at the rate of thirty feet in the year. Dr. Milner mentions that there are many lakes in the steppes of Northern Asia which have no natural outlet. Some of them are many miles in circumference, and have a depth of six and seven feet, from the winter rain, but are entirely evaporated during the summer months. And, according to Irby and Mangles, who describe the effects of evaporation in the Dead Sea, it must be very rapid indeed, notwithstanding the strong saline impregnation of the water. During the rainy season, the increase of the Jordan and other streams is sufficient to raise the level ten or-even fifteen feet; but under the influence of a burning sun and a dry atmosphere, the lake, ina few months, resumes its former level. It remains to consider the loss from absorption. At the last meeting of the Society I expressed great fears that a serious loss might be sustained in the reservoir from this cause; but I have since seen the evidence which Mr. Hodgkinson gave on the subject before the Select Committee, which I consider perfectly satisfactory. To determine the exact amount of water, that will be available for the use of the city, I have now to deduct the loss from evaporation. si Failure of the Yan Yean Reservoir. 133 Total - - - - : 11 ft. 6% in. Deduct evaporation - - - - 9 0 Balance - - - - - 2 64 Required for present wants - - - 3 8 Balance deficiency - - - - 1 14 This is indeed an unfortunate result of the gigantic opera~ tions and large expenditure already incurred at Yan Yean. And it seems not a little extraordinary that such unlimited confidence should have been placed in the abundant supply of water; and it is no less extraordinary that Mr. Blackburn, with a knowledge of the immense loss sustained from evapor- ation in the marshes, should have urged the necessity of rescuing the river from this slough of despond only to plunge it into an abyss of greater magnitude, where it would be scattered, contaminated and rapidly dissipated. But it will probably be said, that as 1 have only shown a deficiency of one foot and one and a half inches, which is rather less than one third of the amount required, I may be in error in my estimate, and perhaps the winter rains may furnish the amount. Now, I shall admit that in some seasons even double this amount may possibly be added to the reser- voir from this source, but I do not think that this need be regarded as a subject of congratulation. With a stream of pure water, encircling this city like a horse shoe, the inhabi- tants will not willingly pay £650,000 to be subjected to the chances of the seasons, to be dependent on the casualities of rain for the first necessary of existence; and, if we must speculate on chances, how often do we have summers remark- able for droughts, and the prevalence of hot winds? And, what we gain by casualties of rain, we shall certainly lose by the casualties of evaporation. An inch a day, for hot winds, which as we have seen is a small allowance for a temperature of 96°, would make short work with two feet in the reser- voir, and this is the greatest addition which could reasonably be expected from the ordinary rainfall of the winter months. It will be readily admitted that in estimating the available discharge of a river for the supply of a large city, it is necessary to take a low average, instead of the mean for a number of years, because it is essential to know what amount can really be depended upon for each year, as the water supply of a city should be placed beyond the reach of casualties. The late Mr. Blackburn was fully impressed with the importance of this principle, hence he assumed his measure- 134 Failure of the Yan Yean Reservoir. ment of 5,000 gallons per minute in‘December as a reliable average. My own estimate, on the same ‘principle, is 5,833 gallons per minute, allowing two-thirds of increase for the three winter months; but this again is reduced by 900 gallons, which I allow as a minimum, and very scanty supply for the inhabitants of the district. The available discharge is, there- fore, 4,933 gallons per minute, independent of the floods, or six feet seven inches in the reservoir. I do not say that the discharge does not frequently exceed this; but I am strongly of opinion that in some seasons it does not do so. I shall now, however, consider what may be regarded as the highest average, and I shall deduce the amount from the sectional measurements of the river. It may be considered as an axiom, that when a river has defined banks, these indicate its ordinary limits, which it only exceeds in time of floods. In other words, every river ma be regarded as having excavated for itself a bed sufficiently large to hold its ordinary stream. The ordinary stream, therefore; will be confined within the ordinary banks, and the highest average in the winter, unless in floods, will not over- flow the banks. Let us examine the sections of the bed of the river at the entrance of the aqueduct. The mean of the sections gives 28 feet within the banks, and 13-2 feet under the water line. Therefore, with the same velocity of half a mile per hour, the section could contain no more than 5,381 gallons per minute, without flooding the right bank. With double the volume, the velocity would not be increased, according to the usual formule, by one half. Therefore, I con- sider it to be demonstrated, that 8,071 gallons per minute, or three times the January measurement, is the highest discharge of the river, except in floods; and-it is exceedingly rare to find any river in Australia level with its banks for six months in the year. This discharge will give five feet four and a half inches in the reservoir for the six winter months; but it will be observed that it does not include the amount at present lost in the swamps, which I have calculated at 1,830 gallons per minute for the whole year, or two feet five inches in the reservoir. The loss in January, as we have seen, is 3,253 gallons per minute, or at the rate of four feet four inches in the reservoir. Failure of the Yan Yean Reservoir. 135 This estimate is of great importance, as showing the exact amount that may be saved by effectually withdrawing the tributaries from the evaporation, and it may be absorption, of the swamps. If the two feet five inches, therefore, can be saved, it may be added to the five feet four and a half inches. The highest ordinary discharge may be computed thus— the six summer months being taken at 2,537 gallons per minute, or three feet four inches, as measured by the com- mittee in January. ft. in. Six summer months - - - - 1 8 Six winter months - : 5 x Amount lost in swamps - - - 2 5 Total - - = 9 BL Deduct 900 gallons for district - - ae) | 2 Highest discharge of river - - = 8 33 First estimate - - - - - 6 vf Balance in favour of 2nd estimate - - 1 84 Thus my first estimate amounted to six feet seven inches as the ordinary discharge of the river, so that this second or highest estimate has an advantage of one foot eight and a half inches over the first. It will therefore be seen that, even allowing the river to be level with its banks for six months in the year, for which we have no measurements to guide us, still the result is very little more favourable than the first, and cannot with any certainty be depended on; and if one-third of the whole, instead of the scanty allowance of 900 gallons per minute, were left for the use of the district, this highest average discharge would be reduced below my former estimate. The Committee, who were appointed by the Society to investigate the subject in a scientific manner, have arrived at results very different from my own. They do not base their conclusions on the measurements at all, which they profess to disregard, but on theoretical principles, and on certain calculations quite original, and apparently adapted to supply any amount of water that may be required in this dry climate; and they have determined that the discharge is three times greater than my estimate of eight feet. Thus, although Mr. Blackburn, who was ignorant of the 136 Failure of the Yan Yean Reservoir. enormous evaporation in this colony, supposing it to be about three feet, only calculated upon a certain supply for 150,000 individuals, they, admitting nine feet of evaporation, which is equal to an annual loss of water that would supply 327,000 at thirty gallons per head per day, find that there is still sufficient left for a population of 666,000, and very gene- rously leaving one half of this enormous amount for the use of the district, they regard the reservoir scheme as adequate to supply 333,000. Had Mr. Blackburn been spared, how rejoiced he would have been to find his favourite scheme so- singularly developed in so short a time. ‘This appears to be another illustration of the wonderful powers of unlimited extension attributed to the Yan Yean scheme. The proportion of the Committee’s estimate would stand thus: 3,000 gallons per minute for the six summer months, 15,000 gallons per minute for three of the winter months, and 48,000 gallons per minute for the other three winter months. These large amounts are of course intended to include floods, but as I have elsewhere shown that in some seasons we may have no floods at all, and that the very highest flood, supposing it to last seventy-two hours, would only amount to three feet in the reservoir, or less than one-eighth of the whole, the above figures may be regarded as substantially correct. It is a source of great regret to me that my estimate is so much at variance with that of the Committee appointed by the Society, but a thorough conviction that they are in error compels me to call in question the result of their investiga- tions, and to discuss at some length their mode of reasoning on the subject. And here it is necessary to state that the Committee at present consists of only two members, Mr. Christy, civil. engineer, and Mr. Acheson of the Survey Department. . As originally appointed, the Committee contained the names of Mr. Wekey, the honorary secretary of the Society, and Mr. Hodgkinson, of the Survey Department, who, from his great practical knowledge, and long experience in the colony, and having already devoted much attention to the whole subject of the water supply of the city, was peculiarly fitted to aid their labours. : The former withdrew on finding, after mature deliberation, that he could not reconcile his own opinions and calculations with those of his colleagues. Failure of the Yan Yean Reservoir. 137 The latter writes to the Society, “ that although precluded, from want of time, from affording his assistance in the calcu- lations of the Committee, yet, if he could have agreed with the conclusions arrived at by them, he would have appended his name to their report, but he differed very materially from some of their views.” It is much to be regretted, that the Committee thus lost the co-operation. of two of the members, and especially on the grounds above stated, as it is evident, that they, as ori- ginally constituted, would have arrived at very different conclusions, and although I entertain the highest opinion of the professional abilities of Messrs. Christy and Acheson, I have to state, on public grounds, that however competent they may be to draw up a report on the watershed of Eng- lish rivers, with the aid of English tables, they cannot be supposed to have much practical knowledge of the rivers of this country, from their comparatively short colonial expe- rience, and they have never actually seen the river Plenty in the winter months, although their calculations show that they expect nine-tenths of the whole supply from the winter rains. The report, therefore, has lost much of that practical value that would otherwise have attached to any document emanating from a Committee of the Philosophical Society. Finding such an enormous difference between my esti- mate of the watershed of the Plenty basin, and that ar- rived at by the Committee, Mr. Hodgkinson was induced to read a very interesting and valuable paper on the subject be- fore the Society ; and the result at which he has arrived strongly corroborates all my calculations and conclusions with respect to the watershed, which is the fulerum upon which the sufficiency of the supply for a rapidly increasing population will depend. At forty gallons, per head, per day, Mr. Hodgkinson calculates that there will be water for 190,000, so long as there is no drought like that of 1837-38 ; as eae a contingency he thinks the supply of water would Ta A But, it is to be noticed, that this estimate for 190,000 is based on a very important consideration, about which there _ is at present some difference of opinion. He has taken mea- surements of the evaporation from a pond which supplies his house, and calculates that it does not amount to more than five feet six inches in the year. Dr. Davy, on the other hand, who is our highest meteorological authority, regards ten feet as the probable evaporation. Now, at forty gallons P 138 Failure of the Yan Yean Reservoir. per head, the difference between these estimates of eva- poration would supply 123,000; deduct this from 190,000, and we have 67,000 as Mr. Hodekinson’s estimate, accord- ing to this higher rate of evaporation. My own estimate, deducting the same evaporation, would supply 43,000. Regarding these estimates as mere approximations, it will thus be seen that the difference between Mr. Hodgkinson’s and my own is very small, being equal to only ten inches in the reservoir. Now, while the greatest importance is to be attached to Mr. Hodgkinson’s estimate of the watershed of the Plenty, as it is founded on a thorough knowledge of the river, and much practical experience both here and in England, I feel inclined to prefer Dr. Davy’s estimate of the evaporation, and from measurements which I recently made on a larger sheet of water than Mr. Hodgkinson’s pond, I found that in twenty-eight days the evaporation exactly equalled eleven inches, or 0°39 inches per day, which would give very nearly nine feet in twelve months. But, after all, no scientific result can be obtained from ponds and waterholes, unless they are water-tight, which it 4s impossible to ascertain. -Thus, with Dr. Davy’s lowest estimate of evaporation, Mr. Hodgkinson’s estimate of the watershed would supply 94,000, so long as there are no droughts; but Dr. Davy ‘gives us very little hope of escaping from such calamitous visitations. Mr. Hodgkinson likewise expresses a very unfavourable opinion with respect to the quality of the water, when stored in the reservoir, and thinks that the Plenty is more likely to suffer deterioration from a resident population than the Yarra. It is interesting and highly important in this inquiry to know that Mr. Hodgkinson’s estimate of the watershed and my own are still further corroborated by the investigations of Dr. Davy. He is not sufficiently acquainted with the geological character of the Plenty basin to give any exact estimate of the watershed, but, from observations and calculations which he has made respecting the force of evaporation from the surface of the ground, in this colony, he regards one-eighth of the rain, over any large area of surface, as the most that can reach the rivers, under any conditions of slope or geo- logical formation, and he thinks that in many districts the Failure of the Yan Yean Reservoir. 139 proportion of rain that reaches the rivers is much less than one-eighth. Thus, Mr. Hodgkinson, Dr. Davy, and myself, seem to have all arrived, by different and independent modes of inves- tigation, at very nearly the same result. For all practical purposes, our different estimates will produce the same result. I attach very little importance to the determination, on theoretical principles, of the watershed of the Plenty. The only certain way, as stated above, of finding the amount, is to measure the streams at least once a month, in order to get the mean discharge for the year. But, if the aqueduct could be finished within the next two months, we should then have the very best means of practically testing how much water can be obtained from the winter rains. I have availed myself of all the measurements already made, and without deducting the immense loss from evapor- ation in the swamps, have allowed an increase of two-thirds for the greater watershed of the winter months. The members of the Committee have disregarded all these measurements, because they were taken in the summer months, and have calculated the amount of watershed, in accordance with the evaporation tables of Mr. Dempsey, which profess to show the evaporation due to the mean tem- perature of the different months in England, and I should have thought that it required no great amount of scientific knowledge to see that if these tables give a correct result for the mean temperature of England, they are totally inapph- cable to the mean temperature of this colony, and would give a very incorrect result. The Committee, in their report, admit that the evaporation, from the surface of water is nine feet, which is nearly double the evaporation in England. It seems, therefore, a singular oversight on their part, not to see that the force of evaporation from the surface of the ground here must bear at least the same increased proportion, and, in point of fact, the evapora- tion is far greater than double. That portion of the drainage area of the Plenty which is of the clay slate formation, and which may be estimated at fifteen square miles, or one-fourth of the whole, is so much more destitute of vegetation than the cultivated soil in England, that the surface of the ground becomes intensely heated under the influence of the solar rays and evaporation is exceedingly rapid. Thus, the reasoning upon which the Committee rely, to, 140. Failure of the Yan Yean Reservoir. account for their enormous watershed, is the same which has led all other scientific men to the very opposite conclusion. If, according to their view, cultivation of the soil diminishes the rivers, England of all other countries ought to have the fewest and the smallest in proportion to the rainfall, and the extent of surface, whereas, it is exactly the reverse, and, in these respects Australia is the very antithesis of England. A barren, uncultivated and impenetrable soil, absorbs no moisture from the atmosphere, and is very unfavourable for the deposition of dew. Luxuriant vegetation absorbs large quantities of moisture during the day, and is most favourable for the deposition of dew in the-night, and the surface, being protected from the direct rays of the sun, is always cool and moist, and the rain readily percolates through the soil to supply springs and rivers. Mere surface water adds little to rivers, except in floods: it is that which percolates through the soil, and traverses either the superficial, or deep strata, that forms the principal and permanent supply of rivers. A compact and impenetrable soil, such as the Committee believe to be most favourable for river supply, is in reality the worst adapted for that purpose, and it is only in the immediate vicinity of rivers that mere surface water can reach them. The capillary attraction of the soil is too great to allow the rain water to travel over any extent of surface. The varying inclination of the surface also, and numerous other obstacles, oppose its motion. Their illustration of the great watershed of the Dandenong ranges is worthy of notice. Because the surface soil is ankle deep with water in wet weather, they conclude that the watershed must be very abundant, whereas, the opposite conclusion is the more legitimate deduction. The rain, which is so firmly held in the surface soil as to convert it into swampy or boggy ground, cannot reach the rivers at all. It remains there only to be evaporated and lost. It is the geo- logical formation of the ranges, and the close structure of the graniterocks, which prevents therain from draining through the soil, and gives rise to swampy and marshy ground, even on the sides and summits of the mountain, and the same condition occurs in the slate formation, as for example in the swamps above Yan Yean, where the water cannot readily percolate through the fissures, or where there is a subsoil of heavy stiff clay. Failure of the Yan Yean Reservoir. 141- -Mr. Dempsey, himself, entertains the same views on this subject as I have now expressed, and thus the favourite authority of the Committee would be the first to detect their illogical reasoning, and he would be especially astonished, that on such reasoning they relied for justification of their unwarrantable adoption of his evaporation tables, to determine the very important question of the watershed of the Plenty basin, with a totally different temperature from that of England. I have said that about one-fourth of the drainage area of the Plenty is clay slate, and I may add the whole of that of the reservoir, and it is the opinion of Mr. Blandowski, who has made a careful geological survey of the whole colony, that the clay slate formation is entirely destitute of rivers. The rain water quickly disappears through the surface soil, which is composed of the detritus of the slate, and is lost chiefly by evaporation from the surface, which becomes intensely heated by the solar rays, and partly by absorption through the seams and fissures of the strata, to re-appear as springs, at some lower level, either in the ocean or in the beds of rivers; or, as frequently happens, in the waterholes of the. dry creeks and watercourses which have no other permanent supply in the summer months; and this circumstance has led some to entertain very false notions with regard to the evaporation from the surface of water in this colony. Find- ing that their waterholes, on which they depend for their domestic consumption, suffer little diminution in the heat of summer, they conclude that the evaporation is very trifling. Artificial waterholes, sunk in any locality, where the close structure of the underlying rocks prevents the escape of the surface water, will lead to the same erroneous conclusions. With scarcely any exception, the slate strata are vertical, running north and south. Hence, they present the most favourable condition for absorption ; and it is very common to find rivers originating in the granite formation, gradually losing themselves in the districts of the slate formation. I have said that the Committee have calculated the amount of watershed, in accordance with Mr. Dempsey’s tables. I do not say that their calculations are based on these tables; but, to use their own expression, they check their calculations with them. By a method which has never before been applied to determine the watershed of any other country, they find that 57°6 per cent. of the rain in the Plenty basin is evapor- ated, and 42-4 per cent. goes to the river, and then, in order 142 Failure of the Yan Yean Reservoir. to check this result, they consult Mr. Dempsey’s tables, and find that exactly 57-6 per cent. of the ram in England is evaporated, and 42-4 per cent. goes to the rivers; and, for- getting that this colony is not England, and that our temperature is much higher, and that the evaporation from the surface of our uncultivated lands is vastly greater, they regard this coincidence as a proof of the correctness of their theory, and forthwith apply Mr. Dempsey’s English evapora- tion to determine the discharge of the Plenty river in the winter months. This extraordinary coincidence between their calculations and Mr. Dempsey’s tables, even to a decimal fraction, might at first sight, be supposed to prove the mathematical accuracy of both, but a mere coincidence is not to be regarded as a proof of the correctness of either, it is necessary that one or other should first be established on a firm scientific basis before such a coincidence could prove anything at all. I shall not attempt to explain this singular coincidence, though, doubtless, it would form an interesting subject in an essay on probabilities. I have already shown that Mr. Dempsey’s tables give three times the amount of watershed that Dr. Thomson calculated for Great Britain, and I am prepared to show that they give a very erroneous and incorrect result of the proportion of the rain that is evaporated here, for, when corrected for the difference of temperature, they give only one-fourth of the watershed calculated by the Committee, and therefore the data upon which they rely to check their own calculations will prove that they are altogether unworthy of confidence, and must be divided by four to give a truthful result. It appears, from the report, that the Committee chiefly rely on the eastern arm of the Plenty, for the supply of the reservoir. Taking their own measurements in January, as the summer discharge, although, in consequence of rain, it considerably exceeded Mr. Blackburn’s measurement in December, with a velocity of one and one-third mile per hour, it only gives 4,450 gallons per minute, which for the six summer months is equal to three feet in the reservoir; their whole discharge for the Plenty they calculate at twenty-four feet eight inches in the reservoir, therefore the winter discharge for six months wil be eight times the amount of the summer discharge; but the section of the river will only contain three times the volume, supposing the stream to be level with the banks, with the same velocity, and they do not calculate for an increased * Failure of the Yan Yean Reservoir. 143 velocity, as, according to the usual formule it would be very small or difficult to compute. It is thus very important to notice that they assume the six winter months discharge at eight times the amount of the six summer months, while the river, when level with its banks, can only contain three times the amount. They also assume that the river is really level with its banks, although they have never seen it in the winter months; but they are quite satisfied on this point from the evidence of a resident farmer. This, it will be observed, is not very scientific or reliable evidence to check their calculations, or to justify the expendi- ture of £650,000 of public money, and accordingly the farmer’s son, an intelligent lad of nineteen, in his father’s absence, told Mr. Wekey and Mr. George Wilkie, that the river was only half full during the winter months, except in floods, which, with the same velocity, exactly accords with my own estimate of the winter discharge. The principle upon which Mr. Dempsey’s tables are based is precisely the same as that adopted by Dr. Dalton and Dr. Thomson, for ascertaining the watershed. He calculated that 57-6 per cent. of the rain is evaporated, and 42°4 remains to supply springs and rivers. Whether Mr. Dempsey’s tables are the result of his own experiments, or those of others, he does not say, but he - clearly states that the evaporation mainly depends upon the temperature, heat promoting it, cold retarding it, and therefore I cannot conceive that he would commit such an egregious blunder as to apply his tables, without correc- tion for the great difference of temperature, to determine the proportion of the rain evaporated in this colony. In calculating the evaporation from the surface of water here from English tables, I assumed for each month the - evaporation of a corresponding month in England, with the same or a less mean temperature, and I thus obtained eight - feet two inches, which is sufficiently near to Dr. Davy’s es- timate of nine feet to show the correctness of the method. I therefore hold it to be scientifically correct to adopt the same method with Mr. Dempsey’s tables in order to deter- mine the proportion of rain that is evaporated from the ground. I have drawn up three tables for the purpose of illustrat- ing the contrast between the proportion of rain evaporated here and in England, allowing the same proportion to the 144 Failure of the Yan Yean Reservoir. same mean temperature in both countries, and the result is 2-51 inches, or one-twelfth as the proportion of the rain that reaches the rivers in this colony. TaBLE I.—Showing the Mean Rain, and the Mean Temperature, and the Proportion of Rain evaporated in the different months in England, according to Mr. Dempsey :— MEAN BAIN, MEAN TEMP. EVAPORATION. Inches. Degrees. Per cent. Inches. January. . 1°847 361 29°3 07540 February . 1:971 38 0 21°6 0-424 March . . 1°617 43°9 33°4 0°540 April. . . 1456 49-9 79:0 1-150 May .. . 1°856 54:0 94:2 1-748 June. . . 27213 58°7 98:3 2174 July . . . 2°287 61-0 98:2 2°245 August . . 2°427 61:6 ~ 98°6 2°391 September . 2°639 578 80°1 2°270 October . . 2°823 48-9 50°5, 1-423 November . 3°837 429 15-1 0579 December . 1:641 39°3 04:3 07164 Total rain 26-616 Total evaporated 17-648 TasiLe II.—Showing the Mean Rain and the Mean Temperature of the different months in Victoria, and the Proportion of the Rain evaporated, allowing the same per centage to the same Mean Temperature in both countries :— MEAN RAIN. MEAN TEMP. EVAPORATION. Inches. Degrees. Per cent. Inches. January . 1°36 67°94 98°6 1:34 February . 0°95 67-31 98'6 0:93 March . . 1°60 63°92 98°6 1:57 April . . 3°18 60°56 98°3 3:07 May .. 367 54:91 94:2 3°45 June .. 2°41 51:00 79°0 1:90 July .. 2:18 49°34 790 1-71 August. . 3°61 50°66 79:0 2°85 September. 3:27 55:08 94-2 3°08 October . 2°59 58°97 98°3 2°36 November. 427 62°25 98°6 4:21 December. 1°86 66°29 98°6 1°83 ——_ —_—. Total 30°81 Total evaporated 28°30 —_————. —_—— ~~ ne Failure of the Yan Yean Reservoir. 145 TasBie I1I.—Showing the Mean Rain and the amount of Rain evaporated, and the Watershed, or that portion of the Rain that escapes evaporation in Victoria, deduced from Mr. Demp- sey’s Tables :— MEAN RAIN. EVAPORATION. WATERSHED. January . 1°36 1°34 0:02 February . 0°95 0°93 0:02 March . . 1°60 1:57 0:03 April . . 3813 3-07 0:06 eS Maye at StOe 3°45 0:22 June . . 2°41 1:90 051 lye 2102 er 2:18 171 0°47 August. . + 3°61 2°85 0-76 September . 3°27 3°08 0-19 October . 2°54 2°36 0:18 November. 427 4:21 0:06 December. 1°86 1°83 0:03 Total 30°85 28°30 2°51 In illustration of this method I shall take our month of January, which has a mean temperature of 67° 94. On re- ferring to Mr. Dempsey’s tables I find that August in Eng- land has a mean temperature of 61° 6. Now, what can be more just or more in accordance with scientific accuracy, than to conclude that the proportion of the rain evaporated in our January is at least as great as that in the August of England ? In the same way I shall take our July, which has a mean temperature of 49° 34, and I find that April in England has a mean temperature of 49° 9. Am I not then warranted on scientific grounds to assume that the proportion of the rain evaporated here in July is equal to that of April in England? Now it is precisely in this way that I have de- duced from Mr. Dempsey’s tables that 2°51 inches, or one- twelfth of the rainfall adopted by the Committee, represents the proportion that reaches the Plenty. I do not insist that Mr. Dempsey’s tables are correct; but if they are so, then it would appear that the watershed of the Plenty is much less than I made it. His tables give 2°51 inches; I estimated 4°50 inches as the nearest approxi- mation, and there is a vast difference between 2°51 inches and 10°69 inches when multiplied by sixty square miles of surface; and this is the watershed adopted by your Com- mittee for eight months of the year. And as every point is Q 146 Failure of the Yan Yean Reservoir. of importance in this inquiry, it may be asked why the Com- mittee allow no watershed for the four summer months; their own reason is, that they think there is none; this ad- mission, therefore, is not to be regarded.as a set-off for their assuming 10°69 inches as the watershed of the eight months. According to Mr. Dempsey’s tables, the proportion of the rain that reaches the rivers in the four summer months in England is equal only to one-fifth ofan inch. Now, without any correction for the higher mean temperature here, one- fifth of an inch for our four summer months is too trifling to be noticed. This extraordinary error of the Committee in their mis- application of Mr. Dempsey’s tables, leads, as might be ex- pected, to very extraordinary results, and it is necessary to follow out their reasoning to its legitimate conclusion. Above Yan Yean, in January, the river gave three feet four inches in the reservoir in twelve months, and one foot one and a third inches in four months, or two feet two and two-third inches in eight months. The whole rainfall for twelve months, at thirty-one inches, is 68-2 feet in the re- servoir. Deduct the rain for the four summer months, which is equal to 5:77 inches, or twelve feet six inches in the reservoir, and we have fifty-five feet eight inches as the rainfall of eight winter months. Take 42-4 per cent. of this which gives twenty-three and a half feet in the reser- voir as the watershed of the Plenty in eight winter months, according to the calculations of the Committee. Add to this one foot two inches, or one-third of three feet four inches, to represent the discharge of the river for four summer months, and we have twenty-four feet eight inches as the total amount that comes down the river. Of this enormous amount of water, they generously pro- pose to bestow one-half on the district, which will be suffi- cient, as we shall presently see, to flood the river during the whole year, and may therefore prove a source of great inconvenience to the inhabitants. And it is their intention to appropriate the other half for the reservoir. Their calculations may be represented as follows :— i Ft. In. From the river during eight months - 23 6 Do. four summer months - 1 2 Total - - - 24 8 Failure of the Yan Yean Reservoir. 147 Ft. In. Total - - = - 24 8 Deduct one-half for district - : eet? 4 Balance for reservoir . : Shale, 4 Rain in reservoir - = - - 2 a 42-4 per cent. of rain over drainage area of ditto - - 2 4 Total in reservoir - = - Si willis 3 Deduct evaporation - - - - 9 (0) Total for the use of the city - is LSPs This amount will exactly supply, at thirty gallons per head, 333,000; at 100 gallons per head, 100,000. Now, let us contrast twenty-three feet six inches, with two feet two and two-third inches, the discharge for eight months according to the measurement of the Committee. Thus they make the Plenty for the eight winter months contain ten times the volume of water that it does in January, or, accord- ing to Mr. Blackburn’s measurement, in December. It will perhaps be said that this actually takes place in the Merri Creek; but such reasoning, if it proves anything, proves too much. This creek is not a river, and only runs after wet weather, and does not always run in winter; or the _ stream is so small that it can scarcely be said to run in very dry winters. After a heavy fall of rain, the creek is flooded for two or three days, but if the flood water were divided over 365 days, it would be a miserably small amount. If any argument could be extracted from this, it would prove that, because the Merri Creek is at one season many million times larger than it is at another, therefore the Plenty may be so also, which is absurd; besides, this sort of reason- ing has its inconveniences as well as its advantages. If we take the highest flood in the Plenty, and reduce it by a few million times, it would cease running altogether like the Merri Creek, and the City would stand a poor chance of a permanent supply of water from this source. Perhaps it may be thought that the Yarra is an analagous ease, and if it can be shown that it contains ten times the volume of water during the eight winter months that it does in December, so may the Plenty. The Yarra differs in many essential points from the Plenty, and chiefly in this important particular, that it takes its rise in very high mountains 148 Failure of the Yan Yean Reservoir. compared with Mount Disappointment, and these are covered with snow during the winter months. But it has yet to be proved that the Yarra undergoes so remarkable an increase in volume for a period of eight months in the year. This river has an average depth of thirty feet, for a distance of two miles above Prince’s Bridge, and I need scarcely say that it only overflows its banks in floods, which may not occur once in two years. Its level, in the beginning of December, is not more than two or three feet below the average of the winter months, or below the level of many portions of the banks ; with any reasonable increase in the velocity, therefore, how is it possible for the Yarra, with an increase of only one-tenth in its depth or sectional measurement, to carry ten times the volume of water for eight months? We have only then to compare, in the drawings furnished by the Committee, the sectional area of the Plenty, at one or more points, in order to see how impossible it is to believe that the river, during eight months of the year, could contain ten times the volume of water that it does in December. The drawings show that the stream occupies in January one-half of the sectional measurement, that is, one-half of the depth where the banks are perpendicular. Now, as above stated, it may be regarded as an axiom, that when a river has defined banks these indicate its ordinary limits, which it only exceeds in time of floods. Thus, without actual measurements for the winter months, important information as to the volume of water may be gathered from those that are resident on the spot. Dr. M‘Kenna and myself put the question to Mr. Bear, who has long resided on his own property at Yan Yean, if a measurement of the Plenty, on the 12th of December, would give a fair average for the year. He replied, that he thought it would. Now, the meteorological tables show that November is our wettest month, and Mr. Blackburn’s measurement of 2,700 gallons per minute was taken in December; therefore, it is not unreasonable to suppose, that Mr. Bear’s opinion may be very nearly correct. But let us examine the section of the river, at the entrance of the aqueduct, not very far distant from Mr. Bear’s house. With a discharge in January of 2,537 gallons per minute, and a velocity of half a mile per hour, the section could rot contain more than twice the present volume, with the same velocity, without spreading widely over its right bank, which is nearly level. With double the volume the velocity Failure of the Yan Yean Reservoir. 149 would be very little increased. Thus the section could not carry three times its present volume without flooding its right bank. Such a state of things could scarcely escape the notice of an intelligent resident gentleman, if it were to go on for eight months in every year, and yet the Committee of the Society tell us that there is not only three times but ten times the above measurement during eight months in the year. Nor is there the slightest-water-worn appearance on the banks to indicate that they form the ordinary channel of the river for any portion of the year. I cannot at present furnish, on reliable authority, the ave- rage increase of rivers in floods; besides, this increase must bear a constant relation to the rainfall, and therefore to the latitude. The Committee entertain the opinion that, during the eight winter months, the rain falls very heavily here, and that, in consequence, the watershed is very great. Iam not aware of this fact, but, on the contrary, during the four summer months, when they say there is no watershed, we have some- times, in consequence of the tropical heat, very sudden and tropical rains. The increase of our Australian rivers during floods proba- bly ranges from 50 to 100 times the volume of the ordinary streams, and this accords with the opinion of Mr. Blandowski, who possesses a great practical knowledge of the physical peculiarities of the colony. The highest flood lines of the Plenty, with the velocity assumed by the Committee of two- and-a-half miles per hour, give seventy-five times the volume of water that passes Yan Yean in December. How very difficult is the result of their singular and elabo- rate calculations. Having found according to these, aided by the evaporation tables of Mr. Dempsey, that the ordinary stream of the Plenty for eight months out of the twelve, is ten times larger than it is in December, the highest flood limes which they themselves could discover will only permit of a remarkably small increase during floods, the greatest being seven-and-a-half times the volume of the ordinary stream. ! Such a result is so startling and incredible, that it is suffi- cient, in my opinion, to warrant the rejection, by the Philo- sophical Society, both of their calculations and Mr. Dempsey’s tables. ‘ ‘Nor is this result more incredible than that the ordinary 150 Failure of the- Yan Yean Reservoir. stream of the Plenty is not confined within its ordinary banks, but for eight months of the year is widely extended over their level surface; a condition of things which was never witnessed by any of the settlers or residents on the river with whom I have conversed. How much better would it have been for the Committee of a Philosophical Society to have disregarded theory altogether, and to have rigidly adhered to their own measurements, as well as those of Mr. Blackburn and Mr. Hodgkinson, and to have made these the basis of their calculations. Theory, based upon experiments conducted in this colony, would possess a scientific interest and value, but otherwise it is practically valueless. , Speculative philosophers, who embark in abstruse scientific investigations with incorrect or inapplicable data for their guide, will soon find themselves lost in a pathless ocean, with- out a compass and without a chart. Dr. Prout, one of the ablest writers on Meteorology, thus expresses himself with reference to the different estimates that have been made of the watershed of England:— These statements of the water that is condensed and evaporated in Great Britain, can only be viewed as rude approximations; and even admitting them to be correct, they could scarcely be applied with any advantage to an inquiry into the actual condensation and evaporation in other countries or climates, which in all instances must be determined by observation and experiment. Before taking leave of Mr. Dempsey, I wish to state my entire concurrence in the liberal views he expresses with reference to the amount of water required for a city of 100,000 inhabitants. Although, he says, twenty gallons per head might be suffi- cient for domestic and manufacturing purposes, and for the extinction of fires, yet he advocates a constant service of thirty gallons per head, and is of opinion that extravagance in water should always be permitted; and for the purpose of cleansing and watering the streets and thoroughfares, for the supply of fountains, public gardens, and pleasure grounds, and other miscellaneous and occasional purposes, he considers that one-tenth of an inch per day, should be allowed for the whole area. Part of this is supplied from rain, so that for a city covering one thousand acres, he allows fifteen gallons per head additional, making in all forty-five gallons, and if he were consulted about the proper supply for Melbourne, he Failure of the Yan Yean Reservoir. 151 would allow thirty gallons instead of fifteen, as it covers more than two thousand acres; and as the evaporation from the surface is more than double that of England, I am satisfied that he would on this account allow another thirty gallons, or ninety gallons in all, and this is precisely what is frequently used in New York on the constant service principle. The Committee, it appears, hold Mr. Dempsey in high esti- mation as an authority. I am surprised, therefore, that they do not follow him in his liberal views on the water supply of cities. They only allow thirty gallons, but if his views are correct, this amount will leave no water for the numerous important purposes which he enumerates; so that we shall have carefully to guard against any unnecessary waste in or- der that a little may be saved to allay the dust in our streets and thoroughfares. When the object is to obtain a very large watershed from the Plenty basin, they adopt Mr. Dempsey’s evaporation tables, which give nearly the highest theoretical estimate of the watershed for the mean temperature of England, or about three times the amount of Dr. Thomson’s estimate, who was at least equally well qualified with Mr. Dempsey to prosecute any scientific investigation; but when the object is to make the most of the limited supply at Yan Yean, they forget Mr. Dempsey and his water-tables, and, knowing that New York frequently consumes ninety gallons per head, they tell us that Melbourne, which is nearly in the same latitude, and has much more need of a plentiful supply, ought only to have thirty gallons. It is singularly illustrative of the peculiarities of this reservoir scheme to glance at the results arrived at by the Committee. At thirty gallons per head per day, one foot eleven inches in the reservoir will suffice for the city for twelve months. Taking their own estimate of the evaporation at nine feet, it will thus be necessary, in order to store and preserve one foot eleven inches for the city, to put into the reservoir each year ten feet eleven inches, or about six times thie amount required. Thus, for every gallon of water that will be consumed by the citizens for domestic purposes, and for watering the streets, five will be consumed by evaporation at Yan Yean. The contents of the river Plenty represent that small fraction of the rain that nature has rescued for the use of man from the powerful influence of evaporation, under an 152 Failure of the Yan Yean Reservoir. Australian sun. It does seem extraordinary, therefore, with so little to lose, that we should be solicitous, at an immense sacrifice of money, to provide an evaporating basin in the vicinity of the river, sufficiently large to swallow up nine- tenths of the small supply which nature has thus provided for our use. _ I confess to have some impatience for the publication of the full report of the Committee, in order to learn what they recommend to be done with this evaporating basin. A few more such basins, of a size proportioned to our larger rivers, would effectually secure the loss of all our river water, and convert this beautiful province of Australia Felix into an Australian desert. : It may be said that, in commenting upon the opmions o the two civil engineers who form the Committee, it is very unlikely that I should be right, as such questions belong to engineering, and are therefore strictly professional. An attentive consideration of this paper, however, will show that there are no questions involved which any person of ordinary education may not clearly understand and appreciate ; and therefore, simply as a member of the Philosophical Society, it is perfectly competent for me to call in question any novel methods of investigation adopted by the Committee, and to say whether, in my opinion, these are legitimate and scientific, or the reverse. But the great and important points upon which the success or failure of the Yan Yean scheme depends do not belong more to the province of the civil engineer than to the medical profession. I have heard of civil engineers bridging the Menai Straits with a stupendous tube of iron, and tunnelling the river Thames, and building a leviathan steam ship of 25,000 tons, to perform the voyage to Australia in thirty days ; and if the Goulburn River and the King Parrot Creek are to be brought through granite mountains into the Yan Yean reservoir there are still higher and greater laurels in store for our colonial engineers. But Iam not aware of any civil engineer who has published original researches on the subject of Heat and Evaporation. Hitherto this department of science has been chiefly cultivated by members of the medical profession. I never heard of any civil engineer’ who had published original investigations on Meteorology. This subject also owes more to the medical profession than to the civil engineer. Failure of the Yan Yean Reservoir. 153 I know of no civil engineer who has added anything to our knowledge of the watershed of different countries. Original experiments and observations on this subject have been prin- cipally contributed by medical men. Perhaps Mr. Dempsey may be cited as an exception; but I think the less that is said about his evaporation tables the better. I need scarcely add that it is not to civil engineers, but to members of the medical profession that we owe all our know- ledge of the impurities of water, and their injurious effects on health, as well as the best and most effectual means of remoy- ing and counteracting them. And we are especially indebted to Dr. Hassall, of London, for his laborious microscopic ex- amination of the impurities of all kinds that abound in the water that is supplied to the city. Dr. Clarke, Professor of Chemistry in the Marischal Col- lege, Aberdeen, is acknowledged to be the highest authority in England, in all questions connected with the water supply of cities; and Dr. Smith, Professor of Chemistry in the Uni- versity of Sydney, who for some years conducted all Dr. Clarke’s practical investigations, is the highest authority on such questions in the Australian Colonies. I think it will be admitted, therefore, that the scientific subjects considered in this paper come strictly within my own province, as a member of the medical profession, and that there is no reason why I should be disqualified to discuss them in a scientific manner; and I think I have sufficiently demonstrated, by legitimate reasoning, that the calculations of the Committee are not based on any correct or scientific data at all, but purely on speculations and assumptions of their own, and that the results to which they lead, when thoroughly investigated, are so incredible, as to carry with them their own condemnation. In my estimate of the water available for the reservoir, I consider that ample justice has been done to all the sources of supply. : I have shown that, at the time of our late visit to Yan Yean, the whole discharge above the swamps was 5,790 gal- lons per minute, and, that of this amount, 3,253 gallons per minute were lost by evaporation in the swamps, or at the rate of four feet four inches in the reservoir; and I have taken for granted that effectual means will be adopted to prevent this loss, which, I have before stated, amounts to two feet five inches in the reservoir in twelve months. The total amount of supply for the reservoir I have estimated at eleven feet six R 154 Failure of the Yan Yean Reservoir. and a half inches: so that, deducting two feet five inches, there will only remain nine feet one and a half inch, or just sufficient to cover the evaporation from the surface. In the meantime, therefore, until such means are adopted, it may safely be asserted, that there will be no water for the city at all: and it is rather a singular circumstance, that if we are to get any supply for the city, it must be by saving the two feet five inches that are at present lost by evaporation, and very probably also by absorption in the swamps, and if this can be done, there will be a supply for 71,500, at forty gallons per head per day. To bring both arms of the Plenty to Yan Yean, clear of all loss from the swamps, would be a very difficult undertaking. The swamps are only to be likened to large sponges, and simply to cut a watercourse through them, and lower their level, would have very little effect in withdrawing the stream from their influence. : The evaporation would continue nearly the same, and would be fed from the current. The eastern swamps are about three miles in length, the western five miles; and I am strongly of opinion, that the loss from evaporation and absorption, could be saved in no other way than by conveying both branches in iron pipes. Mr. Christy has kindly favored me with an estimate of the cost of laying suitable pipes for this purpose, which would amount to £14,000 per mile, or to £42,000 for the eastern branch, and £74,000 for the western. So that, after all, it may become a grave question, whether it be really worth while to go to any expense at all to save either branch from the evaporation of the swamps. I have also taken for granted that we shall have sixty hours of floods each year at Yan Yean, while it is not unusual to have no floods at all; and I have allowed an increase in the Plenty of two-thirds, during the three winter months, for rain; although we sometimes, as last year, have very little rain in winter, and I have allowed a rainfall of thirty- six inches for the reservoir, although it is very doubtful whether there really is that average at Yan Yean. And, I may well ask, what became of the thirty-six inches of rainfall in 1851? I have no doubt that there isa larger and more constant rainfall at the Dandenong Ranges; but they are much nearer the Bay than Mount Disappointment, and there- fore attract and intercept the rain-clouds, and it is well known that there is a greater rainfall near the coast than further in- Failure of the Yan Yean Reservoir. 155 land. This is well exemplified in Melbourne, where we have many showers of rain which do not extend ten miles out of town. I have allowed four inches for dew over the whole basin of the Plenty, an amount of water which would give eight feet eight inches in the reservoir; although it is very probable, in this dry climate; that there may not be two inches; and I have allowed two inches for the reservoir, without any scien- tific data to show that dew would be deposited at all; and, from an estimate which I have made of the whole watershed of the Plenty, based on scientific data, it appears that I have given the reservoir the advantage of nearly the whole amount. And, what is of greater importance than all else, I have deducted nothing from the supply of ordinary seasons on ac- count of droughts, of which we have had ample and painful experience in other parts of Australia; and a gentleman, who has recently returned from Adelaide, has told me that they have scarcely had any rain there for the last eighteen months. I must not omit to mention here, that it is intended to have two intermediate reservoirs betwixt Melbourne and Yan Yean,—the one at Pentridge, the other near the Plough Inn. Your Committee requested information respecting their extent of surface, with a view to determine the amount of loss from evaporation, but they were refused all information on the subject. I have, therefore, been unable in my estimate to make the necessary deduction for their evaporation. T shall only further add, in support of my statement that ample justice has been done to all the sources of supply, tha while I place implicit confidence in Mr. Hodgkinson’s opinion respecting the retentive nature of the bottom of the reservoir, there are not wanting others, who have had great experience in this colony, who think that the chances are very great indeed that in some parts of the vast extent of the reservoir, the water will find its way through the fissures of the clay slate to a lower level. I need not say there is no remedy in such acase. £2,000,000 would not suffice to puddle a surface of 7,000,000 square yards. When this scheme was first proposed, I felt astonished to think that the Plenty could supply so much water as was alleged. I imagined, however, that the deficiency might robably be made up by the winter rains over an extensive district. And although I considered this a very objectionable source, I entertained the hope, that with a depth of 25 feet, and a current established through the reservoir by means of the river, and with a perfect system of filtration, the water 156 Failure of the Yan Yean Reservoir. _ might be rendered comparatively pure, and that its inferiority might, to a certain extent, be compensated for by its super- abundance. . It was only lately, in consequence of my visit to Yan Yean in company with Dr. Mackenna, that I was enabled to obtain the information necessary to arrive at more correct conclu- sions, and our astonishment and surprise can be_ better imagined than described, when we compared the diminutive stream of the Plenty with the wide extent of the reservoir intended for its reception; and, indeed, while contemplating from one of the heights the grandeur and singular beauty of this vast plain, the conviction forced itself upon our minds that the whole volume of the river would not suffice during the heat of summer, to wet the surface; and this my subse- quent investigations have proved to he literally true. The evaporation from the surface of the reservoir is equal to one foot per month for the three summer months. Now, the river, at the entrance of the aqueduct, gave 2,537 gallons per minute in January, or three feet four inches in twelve months; and this is above the average for the summer months, as Mr. Blackburn, in the dry summer of 1851, found it reduced in February to 865 gallons per minute, or to nearly one-third. Let us, however, take three feet to repre- sent the discharge; this would give three inches for each of the summer months. Thus, with twelve inches of evaporation, it would take four rivers equal in size to the Plenty, to keep the reservoir wet. And if we take Mr. Blackburn’s lowest measurement of 865 gallons per minute, it would require exactly eleven such rivers to give even an appearance of moisture to the surface of the reservoir. According to the data which I have submitted to you, there is no difficulty in predicting the complete failure of the Yan Yean Waterworks for want of water; and it is important to notice here, that the amount of water in the reservoir, after deducting the evaporation, is far short of the amount that seems confidently to have been calculated upon. Two feet six and half inches, as measured for the whole surface, would give six feet of depth at the lower end, and this is the very lowest point at which it would be practicable to draw off the water. Below this point I consider that it would be altogether unfit for use, and it has never been contemplated to draw it off at so low a level for the use of the City, as the main pipes are intended to be supplied through two openings in the Tower Well, at ten and seventeen feet from the bottom. Failure of the Yan Yean Reservoir. 157 It also appears that the immense extent of the reservoir, which has always been regarded as its greatest advantage, is in reality so serious an evil as to involve the failure of the whole scheme. It is quite clear that the difference between the amount of rain and evaporation will represent the amount of loss depend- ing upon the wide extent of the surface exposed. This difference is six feet, and is equal to nearly twice the whole discharge of the river, as measured by your Committee, above Yan Yean, and is nearly equal to Mr. Blackburn’s estimate of all the tributaries above the swamps. The whole amount thus lost by evaporation in the reservoir, or nine feet, being sufficient to supply a population of 245,500, at the rate of forty gallons per head per day, or 491,000 at twenty gallons, which is equal to a loss of 9,820,000 gallons of water per day. With an unlimited supply of water this immense loss would have signified little, but when the sources of supply are so remarkably inadequate, the case presents a very different aspect. The foregoing considerations afford no prospect whatever of success to the Yan Yean scheme with the existing sources of supply, but it has always been regarded as capable of inde- finite extension from other sources. It becomes necessary, therefore, to consider this part of the subject, in order to ascer- tain how far it may be possible, or practicable, to supplement the reservoir, and thus render it equal to supply, not only the present wants of the City, but a large prospective increase of population. For this purpose it has been proposed to bring the Merri Creek, the Diamond Creek, the King Parrot Creek, and even the Goulburn River itself, into the reservoir. With regard to the Goulburn River, if it were practicable to bring it ints the reservoir, by means of an aqueduct, and if the expense of such an undertaking would not be beyond the means of the colony, there cannot be a doubt that this would render the Yan Yean scheme eminently successful, and Melbourne might then boast of being better supplied on the gravitation principle than any other city in the world. I feel incompetent to give an opinion in a case involving so many difficult questions, and that could only be determined by experienced engineers, after complete surveys of the intermediate country; but it appears to me, independently of the expense, which would be enormous, to be altogether chimerical. The great dividing granite ranges, which must 158 Failure of the Yan Yean Reservoir. have a very considerable elevation above the bed of the Goulburn, without mentioning other difficulties, would render such an amount of cutting and tunnelling necessary, that I fear the idea must be altogether abandoned. Similar difficulties would attend the proposal to bring the King Parrot Creek, which is a tributary of the Goulburn, into the reservoir. The same dividing ranges would have to be tunnelled, and much broken country bridged by aqueducts ; but a scientific survey by competent engineers could alone determine the question of its practicability and cost. And after all, would it be worth while to expend a very large sum in conveying so small a stream from so great a distance? Such a scheme, I apprehend, must be entirely laid aside until it is shown that there is no other cheaper plan of supplying the City with water. The Diamond Creek claims our next consideration. It is a tributary of the Yarra, and, in its upper course, isnot more . than six miles distant from Yan Yean. It is more easy, therefore, to form an estimate of the probable cost of bringing this creek into the reservoir. An engineer, of great practical knowledge, assured me that he would not undertake the work for 50,0002. Besides, unfortunately it is a very diminutive stream, even compared with the Plenty; and, according to my judgment, is barely sufficient to supply the wants of the village of Eltham and the increasing population of this impor- - tant district. This proposal, therefore, merits no further notice. It only remains to consider the Merri Creek as a source of supply, It rises in a swamp of 1,280 acres, which is said to have 30 square miles of drainage area, but there is not asingle creek or watercourse of any description, leading into it, which shows the very small proportion of the rain that drains into it from an area of surface equal to one-half of the Plenty basin. It is proposed to dam up this marsh, and to lead the water by an aqueduct into the reservoir. Let us suppose, therefore, that this marsh really does receive the watershed of thirty square miles, the area of the swamp being two square miles, a rainfall of thirty inches would give a depth of thirty-seven feet six inches, and one-ninth, or four feet two inches would represent the watershed. ‘This, added to the rainfall of the swamp, would give altogether six feet eight inches, which is not sufficient to cover the evaporation; and it would, therefore, be dry for two months in the year. It is useless, therefore, to look to this marsh as a source of Failure of the Yan Yean Reservoir. 159 supply ; and, even were it otherwise, I could never sanction the principle of robbing a thickly-settled district of the fountain-head on which they chiefly depend for their supply of water, which at best is very small in ordinary seasons. So much importance has always been attached to the sup- posed facilities that existed for indefinitely extending the reservoir, when occasion should require, that I have thought it necessary to consider the subject under its different heads ; and I think I have said enough to show that the Yan Yean scheme has nothing to hope for from the principle of indefinite extension; that, indeed, it cannot be extended at all. I forget, however, that there is one direction in which it can be extended, and I owe it to Mr. Hodgkinson for pointing it out. He has given his attention to all the different methods proposed for extending the reservoir scheme, and he has come to the conclusion that by far the cheapest plan of doing so is by pumping from the Yarra; and I readily admit that there is no limit to the amount that may be obtained in this direction. I have thus shown that the sources of supply for the Yan Yean Reservoir are insufficient to make up for the immense loss sustained from evaporation. I have also shown that there is no hope whatever of extending the resources of the reservoir in any direction, unless by pumping from the Yarra. T have also shown that if the two feet five inches that are now lost in the swamps could be saved, this would only supply 71,500, whereas we require a supply at present for at least 100,000. I have also shown that the medical profession here are strongly opposed to the principle of storing water in a large swamp in this climate; and they entertain the worst fears that the pure waters of the Plenty will be rendered perfectly unfit for use by being transferred into the reservoir. And T may add, that while it is found necessary in England to clean out such reservoirs once in five years, on account of the immense quantities of decaying organic matters that accumu- late in them, and render the water offensive and unwholesome, it will be utterly impossible to clean out the Yan Yean Reservoir. At 5s.per square yard, it would cost 1,750,0002; and how would the city be supplied during the twelve months that would be required for cleaning and refilling the reser- voir? It remains to be considered what steps are now to be adopted. It is quite clear that the reservoir must be aban- -doned altogether. 160 Failure of the Yan. Yean Reservoir. From the data which I have presented to you, it will be observed that there is a sufficient supply in the eastern arm of the Plenty for the present population of the city. The discharge of this main branch in January, was 4,450 gallons per minute, and deducting 630 gallons, which I have done to compensate for the previous heavy rains, and to assimilate the amount to Mr. Blackburn’s estimate for ordinary seasons, we have 3,820 gallons per minute, which is equal to five feet one inch in the reservoir, and would, therefore, suffice for a population of 138,600, supposing the whole to be conveyed in iron pipes without loss. Here, then, is one source of supply, and the water is pure and unexceptionable. But there are certain considerations of great moment con- nected with this source. In a dry summer, such as that of 1851, the supply would, according to the measurements of Mr. Blackburn, be reduced by one-fifth, therefore this source can only be depended on to afford a constant supply for a population of 110,000. And, according to Mr. Blackburn and Mr. Hodgkinson, a drought of eight months, or of one year’s duration would diminish it still further, if not dry it up altogether, as the western arm has been more than once. Another very weighty consideration is, that the present stream of the Plenty is entirely dependent on the eastern branch for its supply, the western being evaporated and lost in the marshes. If this supply therefore is cut off, the Plenty will cease to run altogether, unless the western arm be conveyed for a distance of five miles clear of the swamps, which I fear will be found a difficult and expensive operation. It could be done without any loss by laying a thirty-six inch pipe; but the cost, according to Mr. Christy’s estimate, would be 70,0002. By adopting efficient means to save the western arm from evaporation, and to restore it to the natural channel below the swamps, the stream might be maintained, notwithstanding the appropriation of the eastern arm for the use of the City. The Government and Legislative Council have therefore seriously to consider if it be right or proper that this rapidly increasing City should be dependent on a source which is only equal to supply a population of 138,500 in ordinary seasons, and 110,000 in very dry summers, and in severe droughts perhaps nothing at all. And it is very important to bear in mind, that if we are to pay for bringing water by gravitation from a distance of twenty-five miles, we are not: Failure of the Yan Yean Reservoir. 161 necessarily restricted to the eastern arm of the Plenty, even supposing this source to be one on which we could at all times depend. In the report of the Select Committee already referred to, I find that Mr. Blackburn, after a careful survey of the Yarra, ascertained that at a distance of twenty-five miles from Mel- bourne there is a sufficient head in the river to supply the City on the gravitation principle. Mr. Christy has kindly estimated for me the cost of laying a thirty-six inch pipe for a distance of twenty-five miles, and it amounts to the enormous sum of £369,900. If therefore we are to bring our water into the City from this great distance, I think it will not be denied that it is far better to leave the eastern arm of the Plenty altogether, and go at once to the Yarra, where we shall have as much water as a thirty-six inch pipe can deliver, which I have no doubt would suffice for a population of at least 500,000. And it is also most important to bear in mind that a work of such magnitude would never have been thought of for a moment if it could have reached no further than the present wants of the City. The preference of the gravitation scheme was entirely based by the Commissioners on its supposed capability of supplying at least four times the present population of Melbourne, and on the facility with which it was believed that the works could at any time be indefinitely extended; and it was only very lately that Mr. Jackson, the engineer of the works, is reported to have made similar statements in a paper which he read before the Victorian Institute of Science. I shall take the liberty of quoting a paragraph from the news- paper report :—“ The numerous advantages of the Yan Yean Reservoir Scheme were pointed out; several interesting particulars were stated in the paper. The Yan Yean scheme it appears can be extended indefinitely, without any addition to the reservoir, so as to supply Melbourne with water even if it attained the population of London. It was suggested that the cheapest plan of supplying Geelong might be from the same source which is intended to supply Melbourne.” It is foreign to my purpose to discuss, in this paper, the opinions which Mr. Jackson has published on the subjects of which I have treated; but, as it eminently concerns the public to know the kind of data upon which the Commissioners base their extraordinary expectations of success, I shall add a few il- lustrations of the scientific views entertained by their engineer. Having disposed of Mr. Hodgkinson’s pumping scheme, and all other plans for supplying Melbourne and Williamstown s 162 Failure of the Yan Yean Reservoir. from the Yarra, as impracticable and absurd, Mr. Jackson considers that the Merri Creek swamp, were it not for its distance, would be a very eligible site for a store reservoir for the City; and says, that it receives the drainage of about thirty square miles. He says, also, “the necessity of constructing a store reser- voir would not be manifest to a casual observer, but, as it would appear from the evidence of those settlers who have been established on the banks of the River Plenty for the longest period of time, that at a ford known as the Bridge Inn Ford, the Plenty has been known, on several occasions, to cease to flow, the necessity becomes more obvious.” He further says, “I found that the Yan Yean reservoir would receive the drainage of eighteen square miles. (Mr. Hodgkinson’s measurement is four and half square miles) an area which, in my belief, is sufficient in itself to afford an ample supply of water for the City, without looking to any other source; but, as droughts of two or three years’ standing have been known to occur, I consider it advisable to lead in the Plenty River.” He further adds, “that the reservoir can be made to receive, in addition to the Plenty River, the drainage of upwards of 120 square miles of surface.” The Survey maps give sixty square miles as the area of the Plenty basin. It needs no additional arguments, as it appears to me, to show the great advantages which a Yarra gravitation scheme would possess over a gravitation scheme having the eastern arm of the Plenty as its only souzce of supply; but if these are wanted, they will be found in the fact that if we are to be satisfied with the supply of our present wants only, at the enormous cost of 369,900/., and if we are to depend upon the eastern arm of the Plenty for this supply on the constant ser- vice principle, we have no guarantee whatever that our wants will really be supplied after all, or that the supply will be equal to the actual demand. At forty gallons per head per day, the eastern arm is no doubt fitted to supply 100,000 inhabitants, if we are prepared to chance the droughts; but it has been practically found that there is no way of limiting each indivi- dual to his forty gallons, if the distribution is on the constant service principle. And the Comissioners of Sewerage and Water Supply, backed by the opinion of the Select Committee, have, very properly, from the first, determined to supply the City on this principle, and it would be a sad retrogression in sanitary economy to revert to the antiquated method of inter- Failure of the Yan Yean Reservoir. 163 mittent supply, with its cumbrous machinery of dirty and ill-conditioned cisterns. ge % The constant-service principle, therefore, is not at all adapted for a limited supply of water, and this important fact has been clearly demonstrated by the experience of other cities. Croydon, which is supplied on this principle, con- sumes 500 gallons per house per day, which, making the usual allowance of five individuals to each house, is equal to 100 gal- lons per head instead of forty. Hitchin consumes 235 gallons per house, or forty-seven gallons per head. Whitehaven 250 gallons, or fifty gallons per head; and New York, which is nearly in the same latitude as Melbourne, and is therefore our best guide in regard to the amount that may probably be required, on some days consumes ninety gallons per head instead of forty. At Rugby, Sandgate, and Barnard Castle, the supplies have been found inadequate from waste; and the Bristol company have been forced to abandon the constant-service principle altogsther. With such important facts before us, can we look with any confidence to a source which, under the most favourable circumstances, is only fitted to supply the present population of Melbourne, with its suburban towns and villages. And what is there so very repulsive in the Yarra that we should not at once resort to it for our water supply? After giving my best attention to the whole subject, I would in the strongest manner recommend that we should abandon all hopes of supplying the City from any other source than the Yarra, where, at all times, and under all circumstances, we shall obtain an unlimited supply of the purest water. I am aware that there is a very strong feeling on the part of the public that the works ought to be completed now, as the money is nearly all expended. But more mature con- sideration will show that if any confidence is to be placed in the estimates of Mr. Hodgkinson, Dr. Davy, and myself, the available amount of water, after deducting the evaporation, will not suffice even for the present wants of the City; and with so limited a supply, the water would be unfit for use, were it possible to run it into the pipes, i Where is the object, then, in laying twenty miles of pipes, even under existing contracts ? If the pipes had been laid, it might have been argued that it would be cheaper to carry them five miles further to the eastern arm, at an additional cost of 70,000J., than to remove 164 Meteorology of Melbourne. them to the Yarra. But the main pipes are not yet laid, except for a very short distance; and, therefore, I do not see that it is too late to lay them in another direction, where we shall find at all times the purest water in the most unlimited abundance. But, while I am of opinion that the pipes ought not to be laid, | am most anxious that the capabilities of the reservoir should be tested before finally abandoning it; and, for this purpose, I hope that the aqueduct will be completed in time to take advantage of the winter rains. I may also notice that no steps have yet been taken to convey the two branches of the river through the swamps. This will cost a very large sum, and of course is not yet contracted for. It is deeply to be regretted that a work of such magnitude and importance as that which forms the subject of this paper should be found te be based on incorrect scientific principles; and it shows the vast importance of cultivating the sciences, even in this remote corner of the globe. Had there been a scientific society in this city two years ago, the Commissioners might have obtained more correct information respecting the rate of evaporation in this colony, and more certain and reliable data with respect to the water- shed of the Plenty basin; which were so necessary to ensure the success of their scheme. It was purely on scientific grounds that I was induced to undertake the investigation of this subject; and it was the conviction of its great importance, in a scientific as well as in a sanitary point of view, that has led me to submit to you the result of my inquiries. If there is any probability of the Yan Yean Reservoir scheme failing for want of water, the sooner this unfortunate result is discovered the better. It would surely add little to the scientific reputation of Victoria, that a work of such magnitude should be allowed to be completed, at a ruinous sacrifice of public money, before its failure is even suspected. Ant. XIII.— The Meteorology of Melbourne. ByDr. E. Davy. My attention during a part of the last four months having been directed to the meteorology of this place, I propose to lay before this Society the result of the observations I have Meteorology of Melbourne. 165 made, the inferences which appear to be deduceable from them, and particularly in regard to the nature of the hot winds. Referring to the journal which I have kept since the Ist of December, I must first briefly advert to the thermo- metric observations. It will be seen that the highest point reached by the thermometer has been 112°, in the shade, and the lowest 45° in the night. There has been no night on which the thermometer has not sunk to 74°. We have therefore had none of those very hot or very cold nights, such as are not uncommon in the summers of South Australia :— and the heat, though on some occasions very intense, has in no instance been very continuous. The mean monthly temperature has been estimated in two different ways:—First, by averaging the sum of the daily highest and lowest readings of a Sike’s thermometer. Se- condly, by exposing to the airin the shade a copper vessel, containing ten gallons or more of water, closely covered to prevent evaporation, and taking the temperature of this water twice a day, viz. at 6am. and6 p.m. The results of these two methods of observation have been found during December and January to correspond within a single degree. The mean temperature of December was 68°, and that of January 70°, and that of February 69°, and of March 68° ; bemg ten degrees above the mean of the corresponding summer months in London in 1844. On the two days when the thermometer stood about an hour after noon at the highest point, 112°; viz., on the 28th and 29th January, it sunk in the course of the night to 664° and 66°; thus showing a range of 46° during the twenty-four hours. My observations on the barometer have not been suf- ficiently complete to admit of calculating with precision its mean height. I have recorded the reading of the barometer every day about noon; and during changes of weather, I have observed it at all hours; but not at other times. Approximatively, the reading was for December, 29:82; January, 29°88; February, 30-0. The hygrometric observations are of more immediate in- terest and practical importance. They have been made principally with a Mason’s hygrometer, the accuracy and convenience of which is now generally admitted. It appears that the mean dew point of December was 50:0; that of January, 49:5; and that of February, 50°3; having thus been practically the same during the three months. I have 166 Meteorology of Melbourne. made these observations on numerous occasions at all hours, from six in the morning till late in the evening, and have not found them to differ materially from those made daily about noon, the dew point having been nearly the same during the continuance of brisk wind in the same direction. Deducting the dew point from the mean temperature, gives the dryness of December 18°; that of January, 20-5°; and that of February, 18°7°. The mean of the three is 19-0, while that of England is 8-0°. Thus the dryness of summer in Melbourne is to that of London, as more than 2} to 1; as far as the present season only is concerned. The total rain fallen during the four summer months,— December, January, February, and March, was 4°67 inches.- I may here be permitted to suggest a caution against any deductions from the annual rain-fall of Melbourne being applied to places even at twenty or thirty miles distance. It is well known that in England the annual rain-fall in some places is more than double of that which occurs in London. During the four months in question there has been no appreciable deposit of dew in Melbourne. While on this subject, I may refer to the fallacy of supposing that dew is ordinarily deposited on the surface of water as it is upon that of the land. To attract dew, the surface must be cooled down to the dew point. This on the land is effected by radiation, but not so with the water surface. The cooling effect of evaporation will never reduce the temperature more than half way down to the dew point. A careful consider- ation of circumstances will convince us, that a deposition of dew upon the surface of deep unfrozen water must be a very rare, and almost inconceivable event in this colony. The rate at which evaporation will take place from the sur- face of water depends essentially upon three circumstances,— Ist. The actual temperature. 2nd. The degree of dryness of the air. 3rd. The velocity of the wind. It will, however, be difficult from these data alone, to calculate otherwise than approximatively the true rate of evaporation. Nothing short of direct experiment is to be depended upon; and eyen direct experiment upon a small scale is liable to a slight degree of fallacy. With respect to the temperature there are two observations to be made:—Ist. It is the temperature of the air rather than that of the water which affects the result. The air, on coming in contact with the water, raises or depresses as the Meteorology of Melbourne. 167 case may be, almost instantly to a certain temperature, an infinitesimally thin film of water, and it is from this surface film that the evaporation takes place, however cold the water below may be. This certain temperature will be nearly midway between the actual temperature of the air and its dew point. It is true that the air itself may not only become cooled, but also partially saturated with moisture on passing over a very large surface of water, but in this case, the thermometer and hygrometer ought to indicate a notable difference on the windward and lee sides of the sheet of water. 2nd. The rate of evaporation, as far as it depends on temperature, will be affected rather by the range of the thermometer than by its mean. Inasmuch as the tension of vapour increases almost in a geometrical ratio to the increase of temperature, it is easy to see that if a surface of water were exposed for twelve hours to a temperature of 50° and for another twelve hours to 90° it would evaporate more rapidly than if exposed for the whole twenty-four hours to the mean of 70°. Hence I suppose that evaporation will be more rapid in Melbourne, as compared with London, than the mean temperature alone would indicate. 3rd. The evaporation from any given area of wet land, will be greater in proportion than from a similar area of a sheet of water, because it exposes a greater surface. By direct experiments upon water in different vessels and under different circumstances, exposed to the air during the months of January, February, and March, and comparing these with the hygrometric observations made also in De- cember, I am led to estimate the mean evaporation of the three summer months of December, January, and February, as 0°55 per day, or four feet one and half inches. I have no certain data from which to infer what it may be during the remaining nine months of the year; and would not, therefore, except in the absence of precise information, presume to offer an estimate as a matter of opinion founded upon general observation. I cannot suppose that the evaporation during the six months of spring and autumn, viz:—March, April, May, September, October, and November, is less than half of that which occurs in summer; and I assume that of the three winter months, viz:—June, July, and August, to be one-fifth. We shall thus have Summer se ae 4 1h Spring and Autumn ... 4 1% Winter oe aa 9 9 O feet. 168 Meteorology of Melbourne. It may be greater; but is not likely to be much less than is here estimated; and it may be a question whether this present season has or has not been below the average in point of dryness. The evaporation on the eighteenth of February was more than one inch; the dew point at noon being 37° the mean temperature being 78~, the range 42°, and the highest 99°. I may here state the formula which is given in scientific works for calculating the rate of evaporation from the tem- perature of the air and its dryness. Water at 212° is ascertained by careful experiments to evaporate at the rate of 0°725 grain per square foot per minute. By referring to Dalton or Ure’s tables, the tension of watery vapour at any given temperature can be found. Let T be the tension at the temperature of the air, and T” the tension at the dew-point, than by a simple rule of three sum, HS) SOU ioi Zo le: Be ees pee ase zx being the answer in grains per square foot per minute, from which the quantity in inches can readily be calculated. This rule however affords us no guide for estimating the ratio of increase from the action of wind in proportion to its velocity. The experiments which I have made on the rate of evapora- tion can easily be repeated by other persons, and I have no doubt that the correctness of the results, considered as approxi- mative will eventually be fully confirmed. But of course it is not intended to represent that the level of every natural water hole will sink at the rate of half an inch per day in the summer months, because the contrary is well known. The adjacent soil may be porous and become saturated with water which is altogether protected from evaporation. This water would of course return into the pool, and supply the place of that which had been dissipated by evaporation from the ex- posed surface. It is probably only in cases where the sides and bottom of the pool consists of impervious clay, that the level of the water would sink in anything like the proportion I have mentioned. I have now to speak of the winds of Melbourne; and it will be seen on reference to the Journal, that the prevalent winds are those from the south, or within a few degrees of south. ‘The next in frequency are those from the north and north-west. Winds from all other points of the compass occasionally blow, but are not of long duration. It will, I think, presently appear that this is just what might have been Meteorology of Melbourne. 169 expected on theoretical grounds. Before however explaining my particular views on this subject, it will be necessary to introduce a brief reference to the phenomena of winds generally, and their causes as far as they are well understood. Winds arise from the circumstance that different portions of the earth’s surface are unequally heated, and that air expands and becomes lighter in proportion as its temperature is increased. The air in contact with the overheated surface has of course a tendency to ascend, and a partial vacuum being thus induced, the air from the cooler regions in the vicinity flows towards that point. In order to destroy the equilibrium, it is manifest that the heated air, after having ascended to a certain height, must flow off again horizontally, in a direction opposite to that in which it moved at the surface. It is on this principle, that the great comparative heat of those portions of the earth within the tropics causes a constant flow of air from the poles towards the equator at the earth’s surface and a current from the equator towards the poles in the upper regions of the atmosphere. But in consequence of the motion of the earth in its rotation on its axis being greater in proportion as we approach the equator, the north and south currents of air at the earth’s surface become converted into north-easterly and south-easterly, and, from the converse operation of the same cause, the upper currents returning from the tropics become north and south-westerly. All up to this point is so well understood and appears to be so simple that it almost needs an apology for its introduction into a paper of this description; but, as we further pursue the study of the winds, we shall find that they become modified by the utmost complexity of causes. We shall have to deal with some facts difficult to explain, and with others which defy all our powers of calculation; so that the scriptural saying in reference to the wind, “ Thou canst not tell whence it cometh or whither it goeth,” is still true in the present state of our scientific and geographical knowledge. From what has been above stated, it might be supposed that, irrespectively of local influences, the general tendency of the winds at the earth’s surface in all latitudes should be north and south-easterly. The fact however is, that beyond a certain limit outside the tropics, the prevailing winds are more or less westerly. Explanations of this fact are to be found in different treatises upon the subject; but I have not seen any that entirely meets the case. It appears to me that the fact may be accounted for by the greater amount of friction a 170 Meteorology of Melbourne. and resistance to the wind which occurs at the earth’s surface than in the upper and free regions of the atmosphere. From the influence of this cause it is easy tounderstand that the upper current of air would retain its velocity or momentum in its progress to the poles, so as to be enabled at a certain distance from the tropics to overcome the more sluggish lower current, and force it into its own direction. It is evident that the current of air towards the poles can only be equal to that which is flowing towards the equator; I suppose, therefore, that in the belt in which the westerly winds prevail, the upper current has overcome the lower, only by communicating its own westerly and not its southerly direction. With respect to the winds of Australia it is to be observed that we have a very large island or continent, of a compact form, not deviating greatly from that of a circle, and for the most part remote from any other large tract of land. Of this immense region a part is situated within the tropics, and the remainder very close outside the tropics, so that, having much higher temperature than that of the surrounding ocean, the land may be considered as a vast heating surface, which, on the prin- ciples already explained, will have a tendency to draw currents of air in all directions towards its centre of heat. There can be no doubt that the hottest part of the island exists to the northward, and probably also to the westward of the geogra- phical centre. The influence of the trade winds within the tropics would probably throw this point towards the west ; and, in confirmation of this view, I would observe that the hottest part of the ocean in the vicinity is south of the line, and to the N. W. of Australia, according to Black’s map of Physical Geography :—viz. Java and Timor. For the sake of illustration, we will ‘suppose the hottest point to be in long. 130° and lat. 22° or a little to the N. W. of Sturt’s Desert. Confining our investigations to the southern portions of the continent, we have next to consider that the wind, blowing outside the coast, has a prevailing direction from west to east, and therefore on approaching the coast it would not at once assume a direction towards the centre of heat, but rather a direction intermediate between that and its original eastward motion. On proceeding along the line of coast from west to east, we shall expect, on this principle, to find the westerly character of the wind gradually diminished, and that it willat a certain point become southerly, and beyond that again more or less easterly. Thus in South Australia the prevailing winds ought to be Meteorology of Melbourne. 171 S. W., and in the vicinity of Melbourne almost due east, and still further on south-easterly, and this we find in point of fact to be the case. It is to be presumed that in the upper regions of the at- mosphere, far above the level of the clouds, the returning current of air is almost constantly flowing in the opposite direction to that of the wind which prevails at the surface; that, in fact, the north wind is always blowing over our heads. So long as the pressure of wind from the south is sufficient, as indicated by the barometer standing high, a hot wind, according to my observation, does not generally occur. But let the barometer sink one or two tenths below its pre- vious elevation, and the partial vacuum, of which this is the symptom, is liable to be immediately filled by the air nearest at hand, which is that overhead; and it continues to blow until the barometer either again rises, or else sinks still lower. In the former case, there will be first a lull and then a rapid return of the southerly wind; in the latter case, which, as I suppose, indicates that the hot wind has blown to a certain distance out to sea before it is met by the southerly wind, there will be rain, and the north havin counterbalanced the south direction, the wind will be rather westerly. If the barometer be high, it indicates a tendency to efflux of air in all directions, and no immediate recoil, producing storms or rain, is to be expected. It is a very common thing to speak of the hot winds as though they had blown to us direct from the interior desert, horizontally over the surface of the land. I have even read of a proposition to dam up rivers, so as to form artificial lakes towards the north, in order to mollify them. Such a view of the, case is, however, totally irreconcilable with ob- served facts. In the first place, a remarkable feature in these hot winds is their extreme dryness. The meteorological journal will show that the dew-point of a north wind, when blowing strongly, is always very low, sometimes as low as 35°. This wind is drier than that which would blow from the sea in any direction, and especially from the north at the corres- ponding season of the year. Air may be heated, but can- not be rendered drier, it cannot be deprived of its moisture by contact with hot sand, however dry. Seeing, therefore, that there are no elevated mountains toward the north, we are led to conclude that this air has been dried simply by having risen into the higher and colder regions of the atmo- sphere, where its moisture has separated in the form of 172 Meteorology of Melbourne. clouds. This character of dryness is not peculiar to the hot winds of Australia, In the Deccan the wind has been seen at 90°, while the dew-point has been as low as 29°, or 3° below the freezing point, making the degree of dryness 61° To some persons the doctrine that a hot wind should come from a cold quarter may appear paradoxical. This is not the occasion on which it is necessary or proper to discuss the elementary principles of chemistry or natural philosophy. I may, however, state that air when expanding in conse- quence of mere diminution of pressure, becomes cold indepen- dently of any heat being absolutely abstracted from it: its heat merely becoming latent; and it acquires its original tempe- rature by simply restoring the pressure which previously existed. The experiment of igniting tinder by pressing cold air in a syringe is sufficiently familiar to every one; and the freezing temperature produced by the sudden expansion of air let out of a vessel in which it has been condensed is equally well known. In fact, the cold which exists on the tops of high mountains is attributable solely to the rarefac- tion of the air in those situations. If the rationale of the hot winds, as above recited, be the true one, it becomes easy to understand why it is that hot winds occasionally occur in Van Diemen’s Land and in the Island of Sicily, raising the thermometer above 100°, not- withstanding the great width of the intervening sea, which . ° é might be supposed to have exerted such a cooling influence as to have rendered such a temperature impossible. Barometric observation appears to show that hot winds originate, not so much from an increase above the average in the pressure of the currents from the north, as from the di- minution of pressure from the south and west. To account for this, I must refer to a previous remark as to the compa- rative friction and resistance in varied directions which exists at the earth’s surface. From the absence of this influence in the upper currents of air, and for other reasons, it is legiti- mate to infer that they should be of a much more uniform character, and preserve more nearly a mean pressure; and hence we find that they do not occur when the barome- ter is either at its maximum or its minimum. A northerly wind is frequently, and except during the middle of summer, almost invariably followed by rain. This circumstance at one time appeared to countenance the idea of an inland sea. It admits however of a very different ex- planation; bearing in mind, that from a variety of causes, the irecularity of the earth’s surface, and the meeting and cross- Meteorology of Melbourne. 173 ing of independent currents of air, the winds have a tendency to blow in curves, both horizontal and vertical, rather than in straight lines. When a hot wind blows out to sea, it is cooled by contact with the water; but, at the same time, in consequence of its elevated temperature, it induces rapid evaporation, and becomes loaded with moisture. In proportion to the fall of the barometer, indicating the greatness of the vacuum which originally caused the descent of the hot wind, and the deposi- tion of moisture occurring at the line of its meeting with the southerly wind, will be the tendency of the southerly and westerly winds eventually to become set in motion, in order to restore the equilibrium. The meeting of the cold with the hot wind, both comparatively loaded with moisture, will cause an immediate deposit in the form of clouds and rain. We have in fact the hot wind blown back upon us, ‘after haying been to sea, as it were, to bring back water. We are apt to complain of these hot winds as one of the principal inconveniences of the climate. Had we however no hot winds, we should probably have little or no rain. ‘The southerly winds would not bring it, because as they proceed northward they become warmer and drier, and have less and less tendency to deposit their moisture. Liven the winter rains are usually the consequence of a northerly, although we do not at that season call it a hot wind. The great redeeming feature of the Australian hot wind, is its low dew-point, or in other words, its dryness; but for this _ it would be intolerable. It is easy to conceive that with the thermometer at 112° and the air nearly saturated with moisture, profuse perspiration would be caused, but it would not be removed from the surface of the body, and the effect on the system would be nearly the same as if it were immersed in a scalding hot bath. It were vain to hope, and wrong to wish, that the hot winds of Australia should ever be abolished. But much may be done in the next generation to mitigate theirinconvenience. The cultivation of the land,and especially the extensive planting of trees, will have some influence. The leaves of trees.and shrubs act almost as wet cloths suspended in the air, and the cooling effect of evaporation from their surface is very considerable; added to which, is the probable cold produced by the absorption of carbon, by which an effect, the reverse of that produced by its oxidation or combustion, may be produced. The coolness of ripening fruits may perhaps be accounted for on this principle. The construction of houses, whether in adaptation to the exigencies 174 Meteorology of Melbourne. of the climate or otherwise, of course depends on the will of private proprietors, and all that can be done in this particular, appears to consist in the erection of model dwellings, to show in what manner increased comfort may be obtained, without great Increase of cost. But in the laying out of townships, and the planning of streets, it appears to me that the aspect, with reference to prevailing winds, ought to be taken into con- sideration, and that if this were duly regarded, the nuisance of dust might ina great measure be avoided. The streets and apppoaches might, to a certain extent, be so laid out as to: direct the dust, by the shortest channels, off the town alto- gether. And this, in a district where the prevailing strong winds have so constant a character, would not, as I conceive, be attended with any particular difficulty. Before bringing this paper to a close, I must briefly advert to the continued droughts to which some, at least, of the extra-tropical portions, of the continent of Australia are occasionally liable. In the Sydney district a drought has been known to continue for eighteen months together. The partial failure of the crops of last season in South Australia, appears to be attributable principally to the unusual deficiency of rain during the winter months of May, June, and July. Van Diemen’s Land, notwithstanding its insular position, is not exempt from droughts. I am aware that I am now approach- ing the mysteries of meteorology: and it is not my intention to offer any bold hypothesis upon a subject which, in the present state of our knowledge, is undoubtedly inexplicable. It has by some writers been suggested, that these droughts are periodical, by which I understand that they should be liable to recur at stated intervals. Iam not aware of any sufficient foundation either in theory, or in fact and observa- tion, for such an opinion. ‘There is no particular conjunction of the sun, moon, or planets, which could, upon any known principle, give rise to a drought. I know of no reason why we may not have a drought next year or the year after, without reference to the date of the last occurrence of such a calamity. The droughts of Australia appear to be no more pe- riodical than the tempests which, from time to time, and, for- tunately at distant intervals, sweep the English and other coasts; and we ought at once to disabuse ourselves of this impression. According to the principles proposed in a former part of this paper, the fall of rain will mainly depend upon the frequency and the extent of the alternations of the hot Probable Evaporation at Yan Yean. 175 winds from the interior and the winds from the ocean. Sup- posing the wind to blow continuously in either one of these directions we should certainly have no rain. The dry north wind cannot deposit the wet which it does not contain. The sea breeze, coming from the south, has its tendency to absorb moisture increased as it proceeds northward, and will conse- quently give no rain. If, therefore, we suppose that from whatever cause, at any time, there may be a more than usually steady current and uniform pressure in the ocean winds, off the Australian coast, we find at once, an adequate proximate cause for a drought on the land. As to the ultimate or remote cause, we have at present no data even for probable surmise, unless indeed we ascend another link in the chain of causes, and attribute the circumstance to the accidental absence of storms in the adjacent regions. On this subject at least a point is gained when a fallacy is cleared away. It is to be hoped that the result of simultaneous observations, which, under the patronage of the Board of Trade, are now about to be made at sea, in all parts of the world, will in due time throw a light upon this subject: I now conclude by recommending a co-operation in this important investigation, as one of the most legitimate objects to which the attention of the Philosophical Society could be directed. Art. XIV.—On the Probable Influence of Evaporation on the Quantity of Water to be supplied by the Reservoir at Yan Yean. By CiementT Hopecxinson, C. E., Survey De- partment. At the last Meeting of the Philosophical Society, after Dy. Wilkie’s Paper on the anticipated failure of the Plenty Scheme of Water Supply had been read, and your Committee’s Report received, the President, in the course of a few terse and apposite observations, directed the attention of the members of the Society to the necessity of further elucidation of the phenomena connected with evaporation. I quite concur in the President’s opinion that the excessive difference in the estimated effects of evaporation on the surface of the Upper Plenty District by Dr. Wilkie and your Committee, calls for further investigation. For Dr. Wilkie, on the authority of Thompson’s computa- 176 Probable Influence of Evaporation on the tions for the basin of the Clyde, assumed that in the Upper Plenty District the evaporation would leave only one-ninth of the total rainfall available for the Yan Yean reservoir; whilst your Committee, Messrs. Acheson and Christie, adopted, on the authority of Tables VI., in Dempsey’s treatise on Drainage (which Tables they considered corroborated by their own observations), 0°42 as the amount of the total rainfall available,—a quantity nearly four times greater than that assumed by Dr. Wilkie. Before discussing the very numerous measurements and experiments made in various localities and climates, and which, in the existing want of a regular and connected series of guagings of the Plenty, afford data for arriving analogically at an approximate determination of the propor- tionate amount of rainfall in the Upper Plenty District, I wish first to remark that in a tract of country of specified area comprised by a watershed, the proportion between the total amount of the annual rain falling thereon, and that portion of the rainfall that is carried away from it by the main channel of drainage, depends not only upon the climate, geological structure, and vegetation of such a tract, but also (although in a much less degree of course) upon the greater or less extent of the area; as, ceteris paribus, the greater the area the longer would be the aggregate distance that the rain water would have to traverse in order to reach the point of outfall of the tract, and consequently the longer time would such rain water be liable to evaporation before final departure from the tract in question at the lowest level. Hence, ifa large tract and a small tract present the same physical configuration as regards surface, with the same climate and rainfall, the rate of evaporation for the large tract would be slightly-in excess of that for the small tract. The most extensive and minutely accurate observations ever made in Great Britain for the determination of the evaporation from surfaces of land and water under various conditions, were those taken at Ferrybridge, in Yorkshire, by Mr. Charnock, Vice President of the Meteorological Society of London. These observations were extended over the five years terminating 1846; and tended to corroborate the general accuracy of Dalton’s observations at Manchester for the years 1795, 96, 97... Howard’s Table, referred to in recent computations by Mr. Ranger, the well known Engineering Inspector under the Board of Health, gave for England generally a rate of evaporation rather greater than that observed locally by Dalton and Charnock. In Scotland Yan Yean Reservoir. 1/7 where the rainfall is much greater than in the south of England, and the general temperature and atmospheric influences less favourable for the promotion of evaporation, the latter has been found by the Engineer of the Paisley Water- works and others to be less than in the southern counties of Great Britain. In the following table I have placed in juxta position the results arrived at by different observers. Evaporation from surface Mean | or difference annual |between rain- rainfall.|fall and avail- able supply. Remarks on nature of sur- face to which the observa- Anthority. Locality. a tions refer. Charnock | Ferrybridge 24-6 19:72 |Porous well drained soil Dalton | Manchester | 33-56} 25:15 |} O"dinary mould with 2 Howard oa 36° 30°47 { oan deed oe Small gathering grnd possessing well drain- Thom Paisley 54° 18° ed surface, watered by numerous catch-water drains. Beardmore | Bute 45-4 22°5 {Low country. 4 nae . ‘ : Elevated district, Ditto Rivington Pike) 55°5 3173. { {EAB fe. ahonelaend Dickenson 26°6 15°64 |Ordinary porous soil. Charnock | Ferrybridge ese 32°60 |Moist undrained soil. Ditto Ditto oc 35°03 |Water surface. Dalton Manchester age 44:43 |Water surface. The inferences to be derived from an inspection of this table are,—first, that the values assigned to evaporation from land surfaces by these different authorities are, (with the exception of that given by Dickenson), quite compatible with each other if due allowance be made for the variations of the temperature, geological configuration, soil, and rainfall of the places of observation: and, secondly,—that when the annual rainfall exceeds the annual average quantity, the annual pro- portionate amount thereof evaporated does not also increase as a necessary consequence of such augmented rainfall. I may here remark that Charnock’s observations indicated at the least annual evaporation during the five years over which his ob- servations extended, had occurred during a year when the annual rainfall had been about the average of the five years. This shows the futility of assuming (as too frequently has U 178 Probable Influence of Evaporation on the been done), a certain proportion to exist between the rainfall and the available supply. Mr. Dickenson’s Tabulated Quantities, which indicated an annual amount of evaporation so greatly differing from the results of all other authorities, were, I believe, made for Mr. Parkes, the well known agricultural surveyor, and were in- serted without acknowledgement of their author’s name, in Dempsey’s Treatise on Drainage. But in Table VI. the very great error was committed of obtaining the mean-annual evaporation for the total rainfall of the year by adding up the mean monthly evaporations and dividing the sum by twelve; which result would only be correct if the rainfalls for each month were precisely equal.* Hence the annual evaporation adopted, on Dempsey’s authority, by your Com- mittee, was not only based on observations of an exception- able nature, as just shown, but was also greatly vitiated by a gross mathematical absurdity, which, whether due to Dickenson or Dempsey, was very inexcusable in a pro- fessedly scientific series of Tables. The inadequate rate of evaporation from the ground, as thus assumed by your Committee, is still further shown by its actual application. Thus, if thirty-six inches represent the rainfall at the Upper Plenty, the evaporation, according to the Committees assumed rate, 0.58, would be only 20.88 inches ;—that is, a quantity Jess than has been observed on the average of gathering grounds, whose discharges have been guaged in Scotland, and very much less than has been found to prevail in the South of England. Yet how obviously must the evaporation from the surface of the ground be greater here, even on the most favorable surfaces for lessening evaporation, when the high temperature, hot winds, and clear dry atmos- here of this colony are considered ! Although I cannot admit that the configuration of the surfaces of the Upper Plenty District is so unusually peculiar as to warrant the excessively low rate of evaporation assumed by your Committee, yet a portion of these surfaces * Let B B, BB &e., denote the respective amounts of rainfall in inches for each successive month; %; Es re E, &e., the rates of evaporation corresponding to each successive month; then true mean annual rate of evapo- ER--E R-+LE R-+E R-+-&e.; raion — but according to Dempsey it would be most R+R+R+R+ ke; =) 1 2 3 4 FEPEPE+ &. E erroneously represented by the expression 1 Yan VYean Reservoir. 179 is so far favorable for lessening evaporation, as to render, in my humble opinion, Dr. Wilkie’s estimated rate of evaporation too great. For the steep slopes of the ordinary forest ranges com- prised within the watershed of the Plenty above Yan Yean, promote the rapid conduction of rain-water to the channels of drainage, and therefore tend to diminish evaporation ; this obvious diminution is, however, to a considerable extent, counterbalanced by the increased evaporation that occurs on some extensive tracts of wet undrained land, from whose ~ surface the evaporation is, according to Charnock, nearly as great as from a sheet of water. In this condition are the swamps that extend from the base of Mount Disappointment to the village of Whittlesea,—a swampy tract north of Sher- win’s range, the sides of several of the mountain ravines, and even part of the table land on the main range. From the want of extended meteorological observations taken in connexion with the Upper Plenty districts, or what would have been much more satisfactory, a complete series of stream-guagings to determine the annual discharge, the avyail- able rainfall of the district can be only analogically eliminated from the general data afforded by the most trustworthy English observations on evaporation, corrected for the average differences of temperature for the various months of the year, in London and Melbourne, as given in the Statistical Register for Victoria. Moreover, as wind, and the hygrometrical state of the atmosphere exercise a marked influence on evaporation, independently of temperature; and as their action is more intense here than in England, some additional corrections should be applied to the English data for this increased action. Due consideration must also be given to the favourable nature of part of the surface of the Upper Plenty district, especially that portion draining direct into the reservoir. Having made allowance for all these eon- tingencies I have arrived at the conclusion that the total annual rainfall at the Upper Plenty may be taken as equiva- lent to thirty-six inches, and that the amount thereof evaporated may be assumed to be 30°8 inches, leaving the amount available for supply 5:2 inches, over 44,000 acres. But if cuts were made on the catch water principle the amount available might be greatly augmented. The annual evaporation from the surface of water in England amounts to from thirty-four to forty-four inches. Both Dr. Wilkie and Messrs. Acheson and Christie, have assumed nine feet as the annual loss from evaporation on the 180 Probable Influence of Evaporation on the surface of the reservoir at Yan Yean; whilst Mr. Blackburn considered three feet would be the maximum loss, and others have coincided with his opinion, citing instances of the small decrease in depth observable in certain ponds. Reference to the observed decrease in depth during a specified period in a pond, is of no use im facilitating the inquiry into the amount of evaporation from the surface of the reservoir, unless the rainfall during that period, the area of the pond, and the area of the ground draining into the pond, be given. In the following case these were attainable :—In the vicinity of my residence near the Yarra is a pond, to whose surface I occasionally have recourse for testing the adjustment of my spirit levels. The area of this pond is about one and a-half acres, its greatest depth ten feet, and the area of the ground draining into it about nine acres. The surface of the area of drainage is either trap rock, or a thin coat of soil derived from its disintegration, and resting on a substratum of very stiff impervious clay. The height of the surface of the pond above the nearest point of the Yarra was ascertained by me to be, on March Ist, 1855, fifty-one inches. On December Ist, 1854, one of my men defined, by a peg driven down flush with the surface of the pond, its level on that day, and on March Ist I found the water had sunk 16-2 inches. The proportion of the rainfall draining into the pond, from the small area comprised by its watershed, was assumed to be, for the three months of December, January, and February, 0°15 of the small amount of rain that fell on that area during that period. The rain- fall during the three months was known by reference to the rain guage kept in Melbourne. From these data I com- puted the evaporation for those three months to be 24°6 inches. Having been aware that evaporation from water in small vessels, constructed of materials that are good conductors of heat, proceeds with very much greater rapidity than in large vessels or ponds, I should not feel safe in placing any reliance on the results afforded by the small copper vessels employed by Dr. Davey, and which have led Dr. Wilkie and your Committee to assume nine feet as the annual amount of evaporation from the surface of the Yan Yean reservoir. During the month of February I placed in an exposed site in my garden a large butt, which I filled nearly to the brim with water, and protected the external wood-work of the butt from the influence of the sun and hot winds by woollen rugs. Having unfortunately lost the record of my observa- Yan Yean Reservoir. 181 tions on the water in this butt, I can only state generally that the decrease in depth in consequence of evaporation was remarkably less than according to Dr. Davey’s obser- vations; and that during the prevalence of one hot wind the observed decrease in twenty-four hours wasonly half aninch. I must, however, protest against the greatly exaggerated notions relative to the diminished rate of evaporation in large reservoirs entertained by some practical men. For instance, Mr. Stirrat, the promoter of the gravitation schemes of water supply in Scotland, actually stated in evidence, that in large reservoirs the evaporation was counterbalanced by dew condensed on the surface of the water—a remark, which, if true, would have entirely precluded the possibility of carrying on the well-known process of obtaining salt by evaporation of sea water in large tanks formed near the sea coasts. Tf, in the absence of a complete and satisfactory series of observations on the evaporation during the summer months here, from water contained in a vessel of adequate depth and capacity, well protected from the influences of external temperature, my experiment, made during December, January, and February, on the pond, be considered. to afford some criterion of the probable influence of hot winds upon the Yan Yean reservoir, then the approximate deteriora- tion of the evaporation of the other months of the year can be arrived at with tolerable precision. For if we omit December, January, and February, the mean temperature of all the other months in the year in this colony agree very nearly with the mean temperature of some of the months in England, for which the rates of evaporation from water surfaces have been registered. By basing a calculation on this principle, and applying some additional correction for the frequent occurrence of dry winds here, &c., I have computed the probable evaporation from the surface of the reservoir to be as follows :* INCHES. Evaporation for December, January and February, } 24-6 as determined from my experiments on the pond. Evaporation for March, April, and November, (de- termined by analogical deduction, from a com- 19: parison of English and Australian Meteorological observations, &c. Evaporation for March, Seeeabier! and 1] May. Bo 14:2 Evaporation for June, July, and August. abe 88 66°6 * During the period that has clapsed since the lecture of this paper and my inspection of the proof sheets, the President of the Commission of Sewerage 182 Probable Influence of Evaporation on the In investigating the probable supply of water derivable from the mountains, the possibility of any of the copious streams in the ravines of Mount Disappointment being derived from sources beyond the apparent limits of the water- shed of the Plenty must next be considered. When I guaged these streams and examined their sources in 1852, the fine body of water that I saw gushing out with great velocity from a fissure in the granite, and forming the source of the Saw Pit Creek, on the western branch of the Plenty, led me to investigate this point; as I was aware, that in the island of Hong Kong, copious streams gush out of similar fissures in the granite formation there, and dis- charge a much greater quantity of water than the total rain- fall of the island. But on examining the sources of the eastern branch of the Plenty, I saw that the high table land forming the dividing range between the Plenty and the tributaries of the Goul- and Water Supply has published a vindication of the Yan Yean Scheme of Water Supply. In the course of his observations, he states that I have com- mitted a palpable error, in ignoring, in the above analogical deduction, the dif- ference in the length of days here and in England, for the months of corre- sponding mean temperature; as he is of opinion that the evaporation, on account of longer duration of daylight, is greater in England, during a month of a certain mean temperature, than would be found to occur here, durmg a month possessing the same mean temperature. But Mr. Griffiths, in the caleu- lation by which he illustrates his views on this subject, unfortunately falls into the error of supposing that evaporation invariably ceases at nightfall. I, there- fore, beg to remark, that in this Colony, where dry windy nights are of such frequent occurrence, the nocturnal evaporation is often very great; so muchso, in fact, as to render the correction, to which Mr. Griffiths attaches so much im- portance, of a very trivial and indefinite nature; not, however, ignored by me, as he supposes, but found to be more than counterbalanced by the greater dry- ness of the atmosphere in this Colony. Mr. Griffiths further states, that I am one who would prefer the Yarra, with “its tanneries, fellmongeries, and the thousand other daily increasing sources of pollution,” to the Plenty. The nearest point to Melbourne, at which I ever proposed to derive any supply, was two miles higher up the river than the point where the analytical chemist of the Commission found the Yarra water to be pwrer than the Plenty water; and as regards the nuisances on the banks of the Lower Yarra, below Dight’s Mills, I recollect having once stated the necessity, in my humble opinion, (in a casual conversation with Mr. Griffiths, two years ago,) of some legislative enactment to check the contamination of the water. I have also lately received from T. E. Rawlinson, Esq., Engineer to the Fitz- roy Ward Improvements, a letter kindly conveying to me the result of his ob- servations on the Plenty. Mr. Rawlinson’s high professional standing and long connexion with Yan Yean impart great weight to his opinions on the Water Supply. He considers that the minimum flow of the eastern arm of the Plenty is 4000 gallons per minute, and is convinced, from long personal observation of the Yan Yean Swamp, that the evaporation from the surface of the reservoir will be very much less than has been estimated by some of the members of this Society. 9 Yan Vean Reservoir. 183 burn, was sufficiently extensive to maintain the permanent discharge of the streams in question in the following manner: the rain percolates through the very permeable soil on the top of the range, and lodges in extensive interior cavities and fissures in the granite; and from these subterranean reservoirs the water is gradually exuded at lower levels, through the spongy masses of decomposed vegetation which fill up the external interstices of the granite, and constitute the soil from which spring up, in such rank luxuriance, the gigantic mountain Hucalyptus, and dense undergrowth of tree-ferns and creepers that choke up the ravines of Mount Disappointment. This opinion of the probable cause of the very permanent and regular flow during the summer months of the mountain streams, was briefly enunciated in one of my reports in 1852, and has been since corroborated by Messrs. Acheson and Christie. - During the four hottest months of the year, the enormou quantity of water lost from the effects of evaporation and absorption in the river swamps between Mount Disappoint- ment and Whittlesea (equivalent to a discharge per minute of about 2500 gallons) would render it necessary that, for these months, a quantity of water, equivalent to a discharge of at least 3000 gallons per minute, should be deducted from the total yield of the mountain streams, in order to maintain a sufficiency of water in the Lower Plenty for the adequate supply of the setttlers and stock thereon. During the other eight months of the year, a quantity equivalent to a dis- charge of 2000 gallons per minute would suffice to effect this. The guagings of the Plenty made from time to time by Mr. Blackburn, Mr. Jackson, your Committee, and myself, _are from their want of connexion in a regular series, of little value in affording data for determining the total annual dis- charge of the Plenty. The information afforded by the settlers on that river relative to its winter discharge, floods, &c., is also exceedingly contradictory, I therefore considered it safer, as explained in some of my foregoing remarks, to endeavour to arrive at some estimate of the supply on general principles. I submit with much diffidence the following very rough approximation to the probable amount of population that the Yan Yean scheme would prove adequate to furnish with a sufficient supply of water. Since my lecture of this paper I have however arrived at the conclusion, that sufficient ex- periments on dew have not been made in this colony to 184 Probable Influence of Evaporation on the enable its influence on the augmentation of the water supply to be definitively determined; and as I would wish to give a safe estimate, at any rate, (or less rather than more, than the probable supply), I have now excluded any separate allowance for dew from the calculation. * Supply. GALLONS. Available rainfall, assumed to be equivalent, as already explained, to 5:2 inches, over total surface 44,000 acres, whose drainage> 5,175,950,208 either flows into the Plenty above the cut, or else flows direct into the reservoir. Rainfall on surface of reservoir,—36 pence is on1,300acres cy a 1,058,377,820 6,284,327,528 Demand. Quantity required to maintain an adequate flow } = ehuite dpwer Plenty ne ase f 227,240,000 Evaporation,—66°6 inches from 1,300 acres of e water surface - 1,958,626,618 Contingent allowance for loss of flood-water, during excessive rains, absorption, &c., aI 176,452,848 inches over 1,300 acres Balance, equivalent to the supply, at the rate of twenty-five gallons per head, per day, of a population 313,880 persons, or a population ‘. 2,872,008,067 of about 196,000 if the larger rate of a gallons per head, per day, be assumed . — 6,234,327,528 * Dr. Hales, in his Vegetable Statistics, states, from experiment, that “ the moister the earth is the more dew falls upon it in the night; and more than double the quantity of dew falls upon a surface of water than there does on an equal surface of moist earth.” The author of the recent Report to the Board of Health, on the supply of water derivable from the Farnham Tertiary for- mation, holds the same opinion. Professor Young, in article Dew, in Rural Ency- clopedia, states that a water surface condenses more dew than any other surface. White considered that the permanent character of the ponds occa- sionally met with on the crest of the South Downs was to be attributed to the large amount of dew condensed on the surface of such ponds. The assertion of Mr. Stirrat, in reference to the influence of dew on the large reservoirs on his bleaching grounds, has already been alluded to. It has been supposed by some writers, that water has a capacity to assimilate to itself the vapour in the atmosphere. under certain conditions, even though the temperature of the sur- face of the water should exceed that of the air above it. Unless this capacity existed, the surface of water (if its relative temperature to that of the air be only considered) could seldom effect the condensation of dew. In Great Britain every one must have noticed, on nights otherwise clear and serene, long serpen~ o Yan VYean Reservoir. 185 I have arrived, therefore, at the conclusion, that in ordinary years no fear need be entertained, but that a very abundant supply of water will be derivable from Yan Yean, for a population three times greater than the present population of Melbourne. But that, whenever this colony is again afflicted with such another drought as that of 1838 and 1839, a failure in the supply would occur. The great area of the reservoir will cause the water to be occasionally so violently agitated by wind as to obviate some of the evils that arise from the storage of water. I do not, therefore, anticipate that the Plenty water will undergo much deterioration in the reservoir, unless during the preva- lence of an extraordinary drought. It has been suggested, that if an additional supply of water be required, it could be conveyed into the reservoir either from the King Parrot Creek, on the other side of the - main dividing range, or from the Diamond Creek. I believe the able engineer of the Water Commission could not have examined these streams closely. For I have inspected the source of the King Parrot Creek, and being also acquainted with the country within the watershed of the Diamond Creek, I am induced, from my local knowledge, to form a very unfavourable opinion of this mode of increas- ing the supply. In the case of the King Parrot Creek, a drift-way of considerable length would have to be made, at a great depth below the surface, through hard, igneous or plutonic rock, and the difficulties attending the execution of such an exces- sively costly work, would probably be augmented by the influx of water during its progress. With regard to the Diamond Creek, several of its tributaries, and steep interven- ing schistoze ranges, would have to be crossed, before the waters of the main creek could be conveyed to the Yan Yean Reservoir. In point of fact, the western tributary of the tine bands of mist defining the courses of rivers or large sheets of water; and in Australia I have occasionally, on clear nights, seen similar mists suspended over lagoons, and which mists saturated my hair with moisture on traversing them. Mists of this very circumscribed nature are much less frequent in Aus- tralia than in Europe; yet, if they resulted, as some have supposed, from the temperature of the air being below that of the surface of the water, such mists ought to be of more frequent occurrence here, where the temperature of the atmosphere during night is so remarkably less than during day, and conse- quently the temperature of water surfaces during night generally greater than that of the air. I venture to hope that the phenomena connected with vapour in the atmosphere here will be elucidated by Mr. R. Brough Smyth, whose accurate and judiciously conducted observations will ultimately render his name our chief authority on the Meteorology of this Colony. x 186 Probable Influence of Evaporation on the Diamond Creek, called the Sugar Loaf Creek, would be the only stream that would be practically available as a feeder for the reservoir; and although the watershed area of the Sugar Loaf Creek is very limited, and its discharge in summer very insignificant, much tunnelling through hard schists would be requisite, in order to convey any portion of its water to Yan Yean. The contamination of river water caused by a dense popu- lation on its banks, has been very frequently assigned as a very cogent reason for preferring the Plenty water to the Yarra water. Yet, for that very reason, a decided preference should have been given to the Yarra. For the banks of the Upper Yarra consist, with few exceptions, of steep, rocky, stringy-bark ranges, frequently precluding all access to the water, and totally unsuited for the location of a dense population. But the Upper Plenty District, around the Yan Yean reservoir, is a fine, rich, well-watered, and well timbered tract of country, already possessing within its limits, a numerous agricultural population, and the rising village of Whittlesea, Now, supposing that one of the owners of land abutting on the Yan Yean reservoir, or draining into it, were to convert such land into a township, and by puffing it into notoriety on account of its proximity to a magnificent fresh- water lake, lovely scenery, rich land, and so forth, were to cause the township on paper to become a township in reality, a population of only two thousand persons thus located, would cause a greater amount of deterioration in the water of the reservoir, than would be inflicted on the Yarra by a densely-peopled town of fifty thousand inhabitants formed on the banks of that river at Heidelberg. Although the Plenty affords an unusually soft and excellent water, that of the Yarra, taken from any point above Dight’s Mills, has been proved by a quantitative and qualitative analysis to be yet more excellent; and I see no reason for departing from the opinion I formerly expressed, relative to the superior purity of a supply derivable from the Yarra, above the Yarra Bend Asylum. ‘Those persons whose impressions of the Yarra have been influenced by its sluggish aspect near Melbourne, would have formed a more favourable opinion of this beauti- ful stream had they seen it in the upper portions of its course, where it rapidly rushes down its stony bed with sparkling page oe or else forms foaming cataracts over ledges of rock. In concluding my remarks, I have avoided all allusions to DRAINAGE 60 SDUARE AREA SEcrion cr AQuUESUCT AT BRIDCE OF THE RIVER PLENTY MILES * RESERVOIR | SEcTIONoF EASTERN ARM | AT BRIDGE on Yan Yean Reservoir. 187 the engineering plans and operations adopted for the storage and conduction of the Plenty water, as the high professional standing of the engineer to the commission, and the adminis- trative ability of the president, should be a sufficient guarantee that the details of the scheme will be efficiently carried out. I cannot but regret that I have been compelled to express my dissent from the views entertained by several gentlemen whose judgment and ability I deeply respect, and to whom I beg to apologise for the introduction of their names into this paper. ArT. XV.—Report of the Commissioners appointed by the Philosophical Society of Victoria, to investigate the alleged insufficiency of supply for the Yan Yean Water Works by Dr. Wilkie. TO THE PRESIDENT AND MEMBERS OF THE PHILOSOPHICAL SOCIETY OF VICTORIA. Mr. PRESIDENT AND GENTLEMEN,—In compliance with your resolution of the 9th on January last, requesting us to report on the alleged insufficiency of supply available for the Yan Yean Water Works, as conveyed in a paper read before your Society by Dr. Wilkie on the same day, we have the “honour of laying before you the following report. 1 Our first step in the prosecution of this inquiry, was, to proceed to the Yan Yean reservoir, and to examine its modes of supply, as also the drainage-basin of that part of the River Plenty that is intended to feed it, where we made measure- ments of discharge, in order to guide our conclusions. Our subsequent investigations were directed to ascertaining the different sources of supply and loss, and therefrom ob- taining the available amount. Foremost among the causes of loss stand evaporation, in soils and still water, the former of which, from the various conflicting conditions under which it occurs in this instance, cannot be easily ascertained from scientific deductions, but is rather a practical question, to be dealt with by the results it exhibits; the latter we obtained from the careful experiments and deductions of Dr. Davy, to whom we are much indebted for communicating the results of his valuable experiments. Our aim in arriving at and adopting our conclusions, have been rather to exaggerate our amounts of loss, while we have 188 Report of the Commissioners on the only accepted so much of our supply as was warranted by data, although apparently larger, so that our results might represent the minimum, if not the actual amount. Impressed as we are with the difficulty and intricacy of this question, in a locality where so many conditions come into play, and, consequently not subject to deductions from known data, we approach this subject with great diffidence, and hope that the mode in which we treat it, to the best of our humble abilities, shall receive from your society a candid and con- siderate judgment. We commenced our investigations on the 24th of January, by measuring the discharge of the River Plenty, one mile below the reservoir, at the bridge, being the same place alluded to in Dr. Wilkie’s paper, as measured by him, and giving 153°8 cubic feet per minute, and on which he based the supply by the Plenty, at 3,000,000 cubic yards per annum; our measurement of discharge at this place was only 75:9 cubic feet per minute, deduced from a sectional area of thirty-eight square feet, and surface velocity of :05 feet per second, or only half that of Dr. Wilkie’s discharge. We then followed ‘up the river to the reservoir, at which point we found it diverted into the puddle trench of the new embankment, and dammed. up for the use of a water-wheel, which at once accounted for the smallness of discharge at the bridge, as also Dr. Wilkie’s previous discharge. Proceeding further up, we came to that point of the river where it joins with the aqueduct, or inlet, , for supplying the reservoir, here, finding a clear and uniform flow, we took two aceurate sections, the mean of which, or, 13-2 square feet we adopted, also the surface velocity, from a number of experiments equal to 8-568 inches per second, the mean velocity being obtained by the following formula, double the square root of surface velocity, in inches, deducted from surface velocity, and one added, gives the velocity at bottom, the mean velocity is half the sum of top and bottom velocities, was found to be 6:15 inches per second, hence the discharge was 406 cubic feet per minute, or more than two and half times that of Dr. Wilkie’s discharge at the bridge. Further up we crossed the river at Mr. Sherwin’s Bridge, at which point it flows out of the swamps, and a little above which it divides into two arms, one from the westward, the other from the eastward. We followed up the western arm two miles, the whole of which distance it was nothing more than a swamp, about 100 yards wide, having no defined channel, and over the surface of which, the whole flow of the water is diffused, and exposed to evaporation nearly equal to Yan Yean Water Works. 189 still water, This swamp was composed of vegetable matter to an unknown depth, and so boggy, that a fencing rail was forced into it by one man to a depth of five feet; the flow of water at this point was so trifling that it could not be mea- sured, and was probably all evaporated before reaching the junction with the eastern arm. From minute inquiries we learnt that this swamp extended two and half miles further up, making in all four and half miles of swamp, averaging 100 yards wide, thus exposing 787,000 square yards to surface evaporation. We did not follow this arm up to its source, but we feel satisfied that it affords little, if any, supply to the Plenty during the summer months, and on this occasion none. We then proceeded to examine the eastern arm, which also flows, with the exception of a slight divergence, through a swamp, for two and a half miles above its junction with the western arm. This swamp is two anda half miles long, and averages 700 yards wide, having, therefore, a superficial extent of 3,000,000 square yards; it is charged with water from the eastern arm, and is in some places less boggy than the western arm, and the flow of water through it has a more defined channel and consequently has a less proportionate evaporation. We measured this discharge about two miles up, and found it to be 712 cubic feet per minute, the surface velocity being 10°18 inches per second, and sectional area 14 square feet, the mean velocity being obtained, same as in former case; it is thus 1? times the discharge of the Plenty, where previously measured at aqueduct below the swamp; thus showing, that at that time 43 per cent of the discharge was lost by evaporation in the swamp. Our next subject of inquiry was relative to the source from which the River Plenty derived its supply in the summer months, as it was perfectly evident that there was no surface drainage into it from its basin, excepting after heavy rains, the surface of the ground being quite dry, and the eastern arm the while discharging a strong current of water; to this end we determined to follow up the eastern arm to its source. Proceeding accordingly, we crossed Jack’s Creek, which is a fine tributary to the eastern arm, and through which a consi- derable volume of pure water was flowing; and pursuing the eastern or main arm, we crossed the Sugar Loaf Creek, which is another small tributary of good water being now at the foot of the Ranges, we again crossed the eastern arm at the Ford, and commenced ascending up a deep gully or gorge down which it flows. This gully is clothed with verdant and dense vegetation, consisting of tree-ferns, &c., increasing in 190 Report of the Commissioners on the luxuriance and beauty according as we ascended, having climbed for two miles over dislocated granite rocks and fallen trees, and through dense scrub, we came in upon the river, where it formed a magnificent cascade, the water falling over immense granite rocks for a height of fifty feet, the sides of the stream being formed of granite blocks, in the interstices of which the tree-ferns grew in the greatest luxuriance, forming a scene of great beauty. In this lovely spot we rested under the shade of the tree-ferns, and having tasted the water were surprised at its extreme coldness. We continued our ascent up the stream, sometimes forcing our way through dense scrub and climbing from rock to rock; the stream gradually decreas- ing in volume, being fed from its sides by small supplies of water, which we observed frequently ousing out from a dense spongy mass composed of tree-fern roots and other vegetable matter, on the surface and in the interstices of the granite. We at length arrived at the summit, which is near that of Mount Disappointment, where there was still a very slight stream flowing in a small gully, on apparently table land, where it turned to the left. Having thus traced up the eastern arm of the River Plenty to its principal source, we beg to offer the following opinion as to the mode by which that source is fed :— The eastern arm of the River Plenty, taking its rise near the summit of Mount Disappointment, flows over a granite bed down a deep gully, the sides of which are composed of immense granite blocks, the surfaces of which are covered and the interstices filled with a mass of spongy vegetable matter, capable of retaining a large quantity of water, and . giving it out slowly. The natural fissures of the granite serve the same purpose of storing the water, which was proved by its intense coldness on a very hot day. This description appears to be the general character of the Ranges, and coincides with Mr. Hodgkinson’s report on the source of the western arm. We therefore, conclude, that as these interstices and fissures store an immense body of water obtained from rainfalls, and a moisture from clouds that are attracted over, and lie upon Mount Disappointment, they hence constitute the original and only constant source of supply to the River Plenty. The summer supply of the Plenty is derived wholly from these sources, excepting after heavy rains, as it was evident that it received no surface drainage whatever, when we measured its discharge, but was solely supplied by its eastern arm which led from one of the sources. The discharge of . Van Yean Water Works. 191 the River Plenty, therefore, as measured by us, is only an index of the supply derivable from one of the sources, which has but a limited drainage area, and does not represent the quantity due from the surface drainage of its basin. Hence any calculations founded on this discharge as the only avail- able amount passing through the Plenty, and for supplying the reservoir, must be erroneous, inasmuch as it is onl storage water from the ranges, and not due to recent rainfalls. We are further of opinion, that in consequence of the steep character of the basin in question, facilitating a rapid delivery of its rainfalls into the Plenty, and the Plenty discharge being always dependent upon the amount and duration of the rain- falls, and hence constantly varying, that no single measurement of discharge, at any given time, can be depended upon for a useful result. Impressed with these views, we consider our actual measurement of discharge taken above and below the swamps, as only valuable in furnishing us by their difference, with the amount of loss from absorption and evaporation in the swamps. With a view therefore to estimate the total amount avyail- able from the River Plenty, for the supply of the reservoir, we propose to take the rainfall on the basin supplying that part of the Plenty, as a basis, and from it make deduction for surface absorption, and evaporation loss, by swamps, &c. The River Plenty, above the reservoir, drains a basin com- prising at least sixty square miles of superficial extent, including the southern half of Mount Disappointment and contiguous ranges, it rests, with the exception of the ranges, on the slate formation, and has a close impervious surface, incapable of more than surface absorption, and the whole presents, with the exception of a few square miles, a steep basin-like form, favorable to a rapid delivery of its rainfalls into the Plenty, which is materially assisted by the non- absorbent character of the surface. The mean rainfall upon this basin will therefore represent the total supply of water thereto, the mean annual rainfall for Melbourne, according to Archer’s Statistical Table, is 30-85 inches, or thirty-one inches nearly; in the absence of experi- ments on the rainfall in this locality, we are compelled to accept this amountas the general rainfall, but it was perfectly evident, that over Mount Disappointment, and the surrounding ranges, there was a much greater amount of moisture derived, either from rainfall or atmospheric humidity, or both, due to its superior elevation ; this was abundantly proved by the altered, 192 Report of the Commissioners on the character of the vegetation in the ranges, consisting of im- mense gum trees, 250 feet high, tree-ferns, thick scrub, and other plants, whose growth and luxuriance indicated a great amount of moisture, as also a thick vegetable soil, capable of holding a large quantity of water; but, as this increased vegetation appears to be the effect of the increased moisture, and hence, consumes as nutriment a large proportion of it, if not all, we are hence not prepared to assert that any portion of this additional moisture over Mount Disappointment swells the supply already estimated at thirty-one inches over the whole basin, which depth of rainfall we therefore adopt. Having, therefore, taken the rainfall, we have next to estimate what proportion of it will be delivered into the Plenty, or that amount which is left and flows over, after surface absorption and evaporation. This amount will materially depend upon the declivity of the surface, combined with the imperviousness of the soil, and the number and duration of the rainfalls. In the absence of daia on this subject, in this country, we are obliged to fall back upon English data, although obtained under different conditions. In England, according to G. D. Dempsey’s work on Drainage of Districts and Lands,in Wheale’s Series, the mean annual amount evaporated from the surface of the ground, is 57-6 per cent. of the rainfall, leaving 42-4 per cent. as available for collection; assuming therefore that 58°6 is the correct per centage of evaporation for England, we propose to take such a comparative view of its conditions in England, relatively with those in the Plenty basin, as shall enable us to form a practical judgment as to the applicability of this per centage of evaporation to the Plenty basin. This English per centage of loss of 57-6, is in a country highly favorable to evaporation, owing to its cultivated surface exposing a loose spongy soil, capable of holding a large amount of rainwater while being evaporated by the sun, also to the slightly undulating character of the country, not involving so rapid delivery of its rainfalls into the rivers, and finally from the differences of the rainfalls producing milder showers, a a greater proportion of which must necessarily be evaporated from longer exposure. On the other hand, the basin in question is composed mostly of steep ranges and hills, presenting only a few square miles of flat land, and hence capable of delivering its surplus waters with rapidity into the Plenty; it also has, for the most part, a close impervious surface, undisturbed by agriculture, and only capable of surface absorption, which character of Van Yean Water Works. 193 soil, combined with slope, is unfavourable to loss from evapor- ation on its surface. The rainfalls also being mucn less frequent, and consequently heavier than in England, it is evident that under similar circumstances there would be less loss from evaporation, than if more diffused, as in England. It is reasonable therefore to conclude, that if 57°6 per cent. of rainfall is lost by surface evaporation in England, under circumstances highly favorable to evaporation, a much smaller per centage of the rainfall will be lost when the same circum- stances are very unfavorable, as in the basin in question. We should hence be justified in estimating a much less per centage of loss from evaporation in the basin of the Plenty, were it not that another important question must enter intothe calculation, namely the difference of temperature, equal to ten degrees in favour of evaporation in the Plenty basin, which must act to some extent as a counterpoise against its un- favourable character, for same in other respectsnotwithstanding that the action on evaporation does not last nearly as long as the English temperature. Viewing therefore the conditions of the surface drainage of England relatively with those of the basin of the Plenty, we are of opinion that the English per centage of evaporation of 57°6, if correct, embraces that of the Plenty basin, if it does not exceed it. We hence proceed in our calculations on this assumption, leaving it further on to be shown how it is borne out by the facts. _ This per centage of 57°6 will therefore give 17°856 inches on 31 inches rainfall, the supply from rainfall of 31 inches and loss on same by evaporation will therefore stand thus, Rainfall of 31 inches on-basin of 60 square miles, superficial extent, or 185,856,000 160,042,666 cub. yards. square yards ... ae 200 ae Loss due to surface absorption and eva- poration over same extent, to depth a 92,184,564 cub. yards. 17°856 inches ... ae se “C0 ——<—_—_——— Balance delivered into the Plenty... 67,858,102 cub. yards. Having thusascertained the amount discharged into the Plenty, on this assumption, it is next necessary to determine the amount of loss entailed, by the passage of its western and eastern arms through the swamps. The swamp on the western arm as before stated, has a superficial extent of 787-000 square yards, over which its waters are spread, thus exposing them to evaporation almost Y 194 Report of the Commissioners on the as in still water, to obtain the loss from which, the annual depth evaporated should be multiplied into the superficial ex- tent. We have been kindly favoured by Dr. Davey with the results of his experiments on evaporation in still water, for the three summer months, which give °55 inch per day, equal to 42°5 inches for the three months. He has further furnished us with a proportionate evaporation for the rest of the year, as follows :— Evaporation for the six autumnal months, equal \ UY to four-thirds of the three summer months °° ae Evaporation for the three winter months, equal) 9.5 ; to one-sixth of the three summer months, equal $ 2s: And adding evaporation for the three cua 49-5 aneheR months con ae and ac Boe We have ta aa in ae aa 123°7 inches or 10°3 feet equal depth of water evaporated annually. As this amount was partly derived from inference and therefore not absolutely proved, however certain; we re- quested Dr. Davey to furnish us with such an amount as in his opinion did not admit of a doubt, and were accordingly informed that we might safely adopt nine feet. Hence the amount evaporated in the western swamp can be obtained by multiplying the superficial extent, equal to 787,000 square yards by the depth of evaporation, or nine feet, but as 17°856 inches has already been allowed for surface evaporation over the whole basin, this amount must be de- ducted from the nine feet, thus leaving 7°512 to be multi- plied into the area of the swamp, thus giving 1,970,648 cubic ~ yards evaporated per annum on the western swamp. The loss by evaporation in the swamp on the eastern arm, must be determined in a different manner, inasmuch as the water is not spread over its surface, but rather absorbed by it. This loss is accurately represented by the difference between the measured discharge above and below the swamp on the same day; the discharge of the eastern arm, near the head of the swamp, was on January 24th, 37,990 cubic yards per day, the sectional area being fourteen square feet, and mean velocity 10.18 inches per second; the discharge below the swamp, at junction of the Plenty with aqueduct, was 21,653 cubic yards per day, the sectional area being 13-2 square feet, and mean velocity 6°15 inches per second; the discharge Yan VYean Water Works. 195 above the swamp therefore exceeds that below the same, by 16,337 cubic yards per day, this amount therefore fairly re- presents the rate of loss from evaporation for the three summer months; this spread over the area of the swamp, or 3,000,000 square yards, gives a depth of evaporation of *1958* inches per day, or 17°82 inches for three summer months. Then by Dr. Davey’s rule four-thirds of this, or 23°76 inches, will equal evaporation for six autumnal months, and one-sixth, or 2°97 inches will be evaporation for three winter months, the sum of all these give 44°55 inches for the year, but we have already allowed 17°856 inches for surface evaporation all over the basin, which must therefore be deducted, leaving 26°69 inches depth of evaporation for the year in the eastern swamp equal to 2,224,157 cubic yards. The total amount of loss by evaporation due to the western and eastern swamps is therefore 4,194,805 cubic yards, and this deducted from the amount received into the Plenty already ascertained, or 67,858,102 eubic yards, leaves 63,663,297 cubic yards, equal to the whole amount available for collection from the River Plenty. Having now arrived at the total effective discharge of the Plenty, above the reservoir, and as this result has been obtained on the assumption that 57:6 per cent of the rainfall, or 17:854 inches truly represents the amount of loss from surface evaporation, we now propose to test the correctness of that assumption through the medium of the results obtained therefrom. If therefore the effective discharge of the Plenty per annum, or 63,663,297 cubic yards, obtained on this as- sumption of the correctness of 57‘6 as the per centage of evaporation, be confirmed by legitimate calculations and deduc- tions, it may hence be inferred that the assumption of evaporation itself, or 57-6 is correct. The eastern arm of the Plenty discharges in summer, as before stated, 11°87 cubic feet per second, which we were informed was its ordinary least discharge; the sectional area of this discharge is fourteen square feet, and mean velocity 10°18 inches per second as before obtained; having both which, we obtain the fall in two miles by Eytewein’s formula, as follows :—The velocity in a second is ten-elevenths of amean proportional between the hydraulic mean depth and the fall in two miles, hence the fall in two miles will be 81 inches; now the section of the eastern area at this point is rectangular, and the ordinary winter level, irrespective of floods, as pointed out by a resident on the spot, on particular inquiry, is exactly - three feet above the summer level at this point, hence we 196 Report of the Commissioners on the obtain the sectional area of the winter discharge, equal to forty-one square feet, and having already the fall in two miles equal to 8°1 inches, we can obtain by Eytewein’s formula as above quoted, the velocity equal to 1:15 feet per second, ‘which multiplied by the sectional area, forty-one square feet, gives 47°15 cubic feet per second as the winter discharge. Hence having the summer and winter discharges per second, we obtain the mean discharge by taking the half of their sum, which is 29°51 cubic feet per second, or 34,467,680 cubic yards per annum, and then deducting the loss from the eastern swamp already obtained, equal to 2,224,157 cubic yards, we have 32,243,523 cubic yards as the effective mean discharge of the eastern arm per annum. As the western arm has a larger drainage area than the eastern arm, and the loss in its swamp not so much, and as all its conditions relative to imperviousness, slope, rainfall, &c., are precisely similar, it is evident that it must have at least as great a mean discharge, if not greater; hence the combined mean discharge of both arms will be at least double that of the eastern, or 64,487,046 cubic yards, equal to the effective mean discharge of the Plenty above the reservoir, according to-this calculation. But the result previously arrived at by the application of the English per centage of evaporation of 57°6 of the rainfall, was 63,663,297 cubic yards, thus leaving only 823,749 cubic yards difference between the two calculations. As the calculation of effective discharge for the Plenty, previously made upon the assumed correctness of 57°6 per centage of loss from evaporation is so amply confirmed by this last calculation, we adopt it as correct. The whole effective discharge of the Plenty above reser- voir, or 63,663,297 cubic yards, is therefore the amount available for collection. ‘ But as it cannot be supposed that the whole waters of the Plenty can be diverted into the reservoir, and thus be ab- stracted from the settlers along its banks, we assume that at least half of its whole amount will be retained for their use, leaving the other half, or 31,831,648 cubic yards, for the supply of the reservoir. As therefore this amount has to be conveyed by the aque- duct before mentioned, leading from the Plenty to the reservoir, it is necessary to ascertain the aqueduct’s capacity of discharge, especially as some of this supply will come in the . form of floods, and also the amount likely to be carried down by the Plenty during the greatest ordinary floods. Yan Yean Water’ Works. : 197 One inch rainfall in twenty-four hours is seldom exceeded, and may therefore represent the greatest ordinary flood that may be expected, and as such a rainfall may fall within twenty-four hours, or in half that period, it may be delivered into the Plenty within twenty-four hours from its commence- ment, owing to the steep character of its basin, the loss it is liable to sustain in its passage over the ground into the Plenty will be considerably diminished if the ground was previously saturated, as may be the case, while the loss in the swamp will be increased owing to the spreading out of the water. Taking these circumstances into consideration, we conclude that three-fourths of the inch of rainfall may possibly reach the Plenty and be delivered in twenty-four hours at its junction with the aqueduct. This amount is equal to 3,871,999 cubic yards in twenty- four hcurs, but as half of this amount must remain in the Plenty, the aqueduct will only be required to convey the other half, or 1,935,999 cubic yards in twenty-four houss. We have measured the sectional area of the aqueduct which runs along sideling ground, so that for the most part it only requires a bank on its lower side, that on the upper side being formed by the natural slope of the hill along which it runs. It contained 127 square feet of sectional area, and assuming it had a fall of twelve inches per mile, the mean velocity per second will be, by Eytewein’s formula, ten-elevenths of a mean proportional, between the hydraulic mean depth and the fall in two miles, the hydraulic mean depth being found by dividing the sectional area, 127 square feet, by the wet contour thirty-four feet, equal to 3°73 feet or 44:76 inches, hence the square root of the product of the hydraulic mean depth 44:76 with the fall in two miles, 24 inches, will be the mean proportional, or 32:8 inches, ten-elevenths of which will be the mean velocity, or 29-8 inches per second, this velocity multiplied with the sectional area, 127 square feet, will give the discharge per second equal to 315 cubic feet, or 1,008,000 cubic yards in twenty-four hours. The aqueduct therefore with this sectional area of 127 square feet and assumed fall of 12 inches, (more than which it cannot judiciously have) is insufficient to convey its half of the amount of flood-water by 927,999 cubic yards, but as the banks of the aqueduct were not quite completed when measured, we cannot say what sectional area they will contain when finished, but of this we feel certain, that by raising the lower bank a few feet, the discharge may be doubled so as to include the required amount. - 198 Report of the Commissioners on the But it may be objected that the great body of the flood- water will so spread over the land and flow past that the aqueduct cannot catch its proportion of it, this may be prevented by the construction of a low dam of an inexpensive character. We hence affirm that the aqueduct, with slight additions to its lower bank, will be capable of conveying 31,831,648 cubic yards per annum into the reservoir, with a maximum delivery in time of floods, of 1,935,999 cubic yards in twenty- four hours, being half the assumed amount discharged by the Plenty after a rainfall of one inch within twenty-four hours. Having thus determined the total amount that can be de- livered into the reservoir from the River Plenty, our next subject of inquiry is relative to that derivable from the drainage basin of the reservoir, and also from the rainfall upon its surface, both of which can be arrived at from the data already determined on. The area of the drainage basin of reservoir is 3,000 acres, or 14,520,000 square yards, obtained from Government sur- veys, a rainfall of 31 inches on which will equal 12,503,333 cubic yards; then the amount due to 17°856 inches loss from surface evaporation, as before determined, must be deducted, equal to 7,201,324 cubic yards, leaving 5,302,009 cubic yards derived from surface drainage into reservoir. The area of the reservoir itself is 1,460 acres, equal to 7,066,400 square yards; hence 31 inches rainfall on the area would equal 6,084,955 cubic yards. Hence the different amounts of supply to the reservoir will stand thus :— Supply derivable from the River Plenty... 31,831,648 cubic yards. Supply derivable from drainage area of basin of reservoir wes sao ... 6,302,009 do. Supply derivable from rainfall of 31 inches on surface of reservoir ... 505 ... 6,084,955 do. Total in reservoir “90 ... 43,218,612 cubic yards. ——— This amount, as delivered into the reservoir, is subject to the further loss of evaporation from its surface, already de- termined at 9 feet of depth for still water, which, over a sur- face of 7,066,400 square yards, will give 21,199,200 cube yards to be deducted from the last amount, leaving 22,019,412 cube yards in reservoir. Yan Yean Water Works. 199 This supply is equal to 1014 gailons per head per day, for a population of 100,000 persons. In thus laying before you, Mr. President and gentlemen, the results of our investigations, as also the several modes by which we have arrived at those results, we do so with much diffidence, being fully impressed with the difficulty in obtaining accurate results, under constantly varying condi- tions, resulting from meteorological changes, configuration and character of surface, &c. We believe that refined scien- tific deductions, relative to surface absorption and evapora- tion, however true under certain circumstances, are liable to many sources of error, where so many conflicting conditions have to be meted out, adjusted, and balanced with each other, so that each shall have a consideration consistent with scientific facts. We have not, therefore, attempted to solve this, the most important part of the problem, by such*means, but viewing it more as a practical question due to this parti- cular locality, we have, in the absence of local evidence, applied the data for surface evaporation of another country to this particular case; in the hope that its falsity or truth ‘would be shown in the results it gave, when checked by legitimate deductions, we have shown how those results have been confirmed by the mean discharge on the eastern arm, and the other deduced therefrom. This result of mean dis- charge on the eastern arm was founded on accurate measure- ments, and most minute information as to summer and winter levels, furnished by a most intelligent farmer, in the imme- diate neighbourhood, who told us that the summer level was not lower than what we then saw it, and that the ordinary winter level was at the place of measurement up to the top of the banks, which exactly measured three feet above the summer level, and that the floods were over this again. In calculating the mean discharge, we have made no allow- ance for increase of fall with the increase of volume, but, in ignorance of its amount, have taken it upon the known summer fall of 8 inches intwo miles. We have also taken the discharge at such a point, near the head of the swamp, as to exclude at least six square miles of the drainage basin from the calcula- tion. ‘Taking all these circumstances into consideration, we believe our result of mean discharge is under the actual amount. Our deduction of the mean discharge of the western arm from that of the eastern must appear ooviously sound, when we consider that their conditions are precisely similar, their basins being both in the same formation, having the same soil and character, and therefore haying the same per 200 Report of the Commissioners on the ‘centage of loss from evaporation; their relative discharges must hence be as their superficial “extent, diminished further by their ascertained loss in the swamps. Our measurements of discharge have been obtained by finding the mean velocities, by the following formula, “ dou- ble the square root of surface velocity in inches, deducted from surface velocity, and one added, gives the velocity at bottom, the mean velocity is half the sum of top and bottom velocities.” The calculations of loss from the swamps have been taken with such minuteness as circumstances would permit, that for the western swamp has been taken as if for still water, as the water spreads over the surface. The loss on the eastern swamps was truly represented by the excess of the discharge of the eastern arm above the swamps, over that of the Plenty below the swamps on the day of measurement, as at this time the Plenty was only fed by the eastern arm, the western being wholly lost in its swamps. We have not attempted to disprove Dr. Wilkie’s calcula- tions, by carrying investigations in the same track, as we believe by doing so we could not arrive at a truthful result, inasmuch as he bases his calculations on the summer discharge, which is only derived from storage water in the ranges, which hold the water back and prevent it being delivered more suddenly, hence if there were no ranges there would be no summer discharge, although as much water would pass down. This is the case with the Merri Creek which has 122 square miles of basin, but as it does not rise in ranges, its waters near the source are not stored, but are delivered with rapidity according as they are received, there is therefore no summer discharge, hence measurements of summer flow, unless after rainfall, only indicate the least discharge. It only remains therefore for us to state, it was impossible to follow up Dr. Wilkie’s paper through the several allegations and deductions contained therein, inasmuch as his caleulations are almost wholly based on the fallacy of summer discharge, which we have shown is only due to storage in the ranges, and which therefore only forms the dregs of the actual discharge. The amount allowed by him for floods is assumed, and therefore cannot be depended upon, more especially as there is no defined line between least flow and highest floods, the discharges coming down in. variable volumes between these points, hence the inaccuracy of computing ordinary discharges and floods separately, to obtain the total discharge. We have therefore adopted a different mode of investigation Van Yean Water Works. 201 to obtain those required results which we have now the honour of presenting to you, as representing such amounts of dis- charge and supply as are safely warranted by our calculations and deductions, while we are not prepared to state that they embrace the actual or total amount of same. The following is a summary of the results of our calcu- lations :— Supply from Basin of River Plenty. Cube Yards. Original supply by rainfall of 31 ae on basin of 60 square miles ane Pf s.. 160,042,666 Loss from same— By absorption and evaporation over surface of basin, at the rate of Cube Yards. 57 6 per cent. of rainfall . 92,184,564 By evaporation in swamps ... 4,194,804 ——w Making the totalloss ... ... 96,379,369 Which loss deducted from the original supply by rain- fall, gives the total discharge “of the Plenty, per annum, above the reservoir, equal to The half of this last amount being assumed as the greatest quantity that can be judiciously abstracted 63,663,297 from the Plenty, will represent the total supply to the reservoir from the Plenty basin, equal to Supply from Basin of Reservoir. Supply by rainfall of 31 inches, on basin of 3,000 acres, draining into reservoir Loss on same—from caer ue oT ea over surface of basin, at the rate of 57°6 Lg cent. of rainfall 31,831,648 Cube Yards. 12,503,333 7,201,324 Which amount of loss, deducted from ‘rainfall, repre- ° sents the amount of drainage into reservoir from its basin, equal to a; sels And eke 5,302,009 Supply from Rainfall on Reservoir. Cube Yards. Rainfall of 31 inches, on 1,460 acres, superficial extent of reservoir, equal to . oa Aa ——————awe 6,084,955 Total of various Supplies into Reservoir. ; Cube Yards. Supply from basin of River Plenty -- 31,831,648 Do. do. reservoir ... eae ht 5,302,009 Do. rainfall on reservoir aes aire wee 6,084,955 Total of supplies in reservoir... .. 43,218,612 — 202 Report of the Commissioners on the Loss from evaporation over surface of water in reservoir, at the rate of nine feet deep, on asuperficial extent of 1,460 acres, equal to 21,199,200 cube yards. Which amount of evaporation, deducted from the total of supplies in reservoir, will give the amount of water available for consumption, equal to 22,019,412 cube yards. This total result is equivalent to 1014 gallons per head per day, for a population of 100,000 persons. Before concluding this report, we feel it our duty to represent the deterioration of the Plenty water, owing to the passage of its western and eastern arms through the swamps, we tasted the water above and below the swamps, in the former case it was perfectly clear and refreshing, and free from impurities, as coming from the rock, while below the swamps it had a flat unpleasent taste, and was not nearly so pure as that above the swamps; this deterioration of the water might have been avoided if the site of the reservoir had been chosen above the swamps, on the eastern arm, while the western arm might have been left to supply the settlers, the reservoir could be formed by the construction of a short dam, at the junction of Jack’s Creek with the eastern arm, which would store nearly all the catch of the eastern arm above the swamps, equal to fifteen square miles, thus giving nearly 17,000,000 cubic yards, with a loss from evaporation on about half a square mile of reservoir surface, equal to 4,600,000 cubic yards, leaving 12,400,000 cubic yards, equal to fifty-seven gallons per head of pure delicious water, fresh from the rock, available for the supply of Melbourne, instead of 22,000,000 cubic yards of indifferent water, as in the present reservoir. ; As it is now too late to adopt this scheme (and thereby avoid the loss by the evaporation of 21,000,000 cubic yards in the present reservoir), we are of opinion that the eastern and western arms of the Plenty should be diverted from the swamps through which they pass, by means of open cuts, carried round same, the water would thereby be conveyed into the reservoir as pure as from the ranges, and the loss from the swamps, or 4,194,805 cubic yards being hence avoided, would be added to the reservoir supply, making in all 26,214,217 cubic yards, equal to 121 gallons per head per day. ‘We have now had the honour of submitting our views on this important inquiry, and in conclusion beg to express a hope that the limited materials, in the form of data, local Yan Yean Water Works. ~ 203 evidence, &c., from which we had to draw our conclusions and results, will be borne in mind, in forming an estimate of the mode in which we have treated this important subject. We have the honor to be, Mr. President and Gentlemen, your very obedient humble servants, F. C. Curisty, C.E. F. AcHeEson, C.E. Art. XVI.—On the Influence of the Physical Character of a Country on the Climate; being a Letter to the President, by R. BroucH SmytTH, Esa., Mining Engineer. Museum of Natural History, Melbourne. March 8, 1855. Sir, ! Considerable attention being directed, at this time, to the capabilities of the rivers in the colony of Victoria, in respect of water supply, I have the honour to submit, for your perusal, the following observations :— I am aware that attempts have been made, very recently, to calculate the probable annual discharge of water from a river by computing the drainage area, the rainfall, the eva- poration, &c., but as there are other counteragents, equally worthy of attention, and bearing directly upon the results of such calculations, I propose to offer some remarks, that may, perhaps, arrest the attention of those immediately inter- ested. My present object is more particularly to inquire how far the physical character, and the geological structure of a country, extend their influence over peculiarities of climate and in what manner they serve to determine the hydrogra- phical features. This connexion, Sir, which I shall seek to establish and enlarge, is, as you are aware, not new to those who have made the science of Geology their study. AsI design to apply it, in a practical sense, to the solution of some questions which have been lately brought before the Philosophical Society, I feel that I shall best accomplish this purpose, by divesting it entirely of purely local interest. This increases the difficulties of the subject, which I ap- proach with some reluctance, aware of the many and great sources of error to which all such inquiries are liable; and 204 Influence of the Physical Character yet, if conducted with ordinary care, and with impartiality, it cannot fail to place in a new and important point of view, many questions of great public interest; of greater interest here, than in other climates where the hydrographical fea- tures are of a different character; and whatever errors may occur, they will be out of all proportion to the useful results of such an inquiry. Geological Formations of Victoria— This country may be described as consisting of vast beds of sandstones, shale, and clay slate, members of the Primary Fossiliferous series. These beds are variously contorted, and dipping at angles of 30°, 40°, 60%, and 70°, and they are sometimes ver- tical. Mr. Selwyn,” the Government Geologist, estimates the thickness of these deposits at 30,000 feet or more, and this is probably very near the truth. These sandstones and clay slates have been upheaved by Plutonic rocks, which are found to occupy comparatively large areas. ‘The hills in the Ovens district, Mount Alexander, Mount William, and the hills in the north-eastern parts of the province, are granitic, and excellently illustrate the character of such rocks. Then, there are plains of basalt, sometimes of great extent, where the subordinate rocks are entirely hidden, or only appear in isolated hills of some height, or where denuding causes have removed the upper basaltic formation. Basalt is also found filling the valleys, near the rivers, and in such cases the streams have cut a passage between the former rock and the clay slate; as may be seen in some parts of the river Yarra, in the rivers Coliban and Campaspie, at the Deep Creek near Mount Greenock, and in many of the streams in the western part of the Province. A considerable part of the Great Dividing Range is com- posed of igneous rocks, and they in like manner form isolated hills in many localities, which sometimes attain a considerable altitude—as Larné Baramul, Mount Boninyong, Mount * « Phil. Trans. 1850, p. 354. AA 210 Influence of the Physical Character evaporation ; but it happens that north winds are the excep- tional and not the prevailing winds. When we have south winds, or winds west or east of south, the dew point is com- monly much higher; and though the daily mean temperature may yet be very high, the conditions for rapid evaporation do not exist. Unquestionably, as compared with many other climates, evaporation is very rapid in this country; but I am justified in stating, that the amount of evaporation during the seven months commencing in April bears no proportion to the rapid evaporation during the other five months; and this is owing to the low prevailing temperature, and the moist con- dition of the atmosphere. During the rainy season the daily mean temperature is very low, the air is laden with moisture, and, excepting a few chance days, when a dry north wind prevails, evaporation progresses very slowly. With a tem- perature of 57° the dew-point is not unfrequently 48°or 49°, and even higher; and should the wind come from the west or south-west it sometimes happens that we have an atmosphere almost completely saturated. With the tempera- ture and dew point as above stated, the daily evaporation is seldom more than 8-100 of an inch per diem, under a stiff breeze. In the absence of figures, derived from daily obser- vations, extending over a period of twelve months, I cannot even venture to hint at the amount of evaporation in Melbourne; and how much more should we hesitate to express any opinion as to the amount of evaporation in far distant places, under often changing conditions? It is impossible, I repeat, to calculate the amount of evaporation from tables of temperatures during the several months of the year, unless we are also informed as to the daily hygromeiric condition of the atmosphere, and the force of the wind; and even with that information, the result would be the mere expression of an. opinion, valueless as a matter of fact. I am the more anxious to enforce these’ facts, as, unless they are borne in mind, much valuable time may be mispent in calcula- tions and discussions, not merely useless but dangerous to the true interests of science. Effects of Different Geological Formations.—I will now wind had changed to south, and the thermometer fell to 65°, while the dew- point was 46°. On January 29th of this year, at 113 a.m. the thermometer stood at 109°, and the dew-point at 41°, the wind being from the north; and in the afternoon of that day, at 4 o’clock, the thermometer indicated a tempe- rature of 78°, the dew-point bemg 58°; the wind, meanwhile, having changed. to south. I have drawn these facts from the Meteorological Journal of Dr. Davey, the Assay Master. H,ONS., | J Jones Lith: | The numerous gulleys are, however, aimost- mvariavry covered with a thin stratum of porous sandy clay and gravel, with a pretty strong clay substratum. Even if the ridges of paleozoic rocks were less steep, and better clad with soil, it is evident if they absorbed much of the rainfall, that it would be conveyed to great depths beneath the surface, and could not again appear as springs except under very peculiar circumstances. The granite rocks may retain small supplies of water, which slowly percolating through the close seams of such a rock, will reappear in small patches of swamp or in springs, but these latter are seldom found of large volume. Streams of water which are seen to issue from granite rocks, are usually traceable to some swamp or morass in the / | ie SKETCH OF A SECTION, SHEWING THE GENERAL CHARACTER OF THE GEOLOGICAL FORMATIONS AND THEIR USUAL RELATIVE POSITIONS. Victoria ——— ES \ 7 if LP hh / _s OF | | | I 1 | j | i IT ORCANIC SUBSTANCES AND Ii CARBONATE OF LIME | os : S |*o, —«Orgunre substances 8 \ “cd will evelve severally x a NITROCEN HYDROCEN OXYCEN SULPHUR ety. water yr o. 7 tea dmmonia | SULPHURETTED HYDROCEN -— | KPELLED] - é isulphcte of Amun “9 sulphate ot dyn. intercha nge wt @ Ce riatr, ebowaceary of temper QUITE Sulphate of Ammonia Lime Carbonte Qad CARBONATE OF AMM. [volattlized | ‘SULPHATE OF LIME OR CYPSUM. Aetory ag b Sons Megorr re: Eat : tn ae: by Mae rae D dehapARY ‘ Land round Melbourne. 233 simply pulverised it is an excellent manure for the improve- ment of sour soil, and is much valued as a plastic material for artistic purposes. Gypsum is soluble in water to a certain extent only; that is, till the water becomes saturated with it, it being found by experiment that 1 of gypsum will be dissolved in 400 of water. When exposed to a heat of 424° Fahr., the water entering into the composition of this remarkable mineral is expelled by evaporation, and the gypsum becomes possesged of a peculiar antipathy to any combination with water. If, however, heated to 318° only, it readily re-unites with water, heat is evolved from it, and a dense crystalline mass appears as the result of this combination. This (the efficient degree of heat) is the secret of producing plaster of Paris from the gypsum in its raw or crystallised state. In a purely scientific point of view these crystals possess ' a considerable degree of interest. They occur both in clino-rhombical forms and polygonal columns. Twin or double crystals, of which there are specimens now before the Society, also exist, together with the single ones. These remarkable combinations, presenting a varied field of obser- vation to the ardent admirer of nature, are so perfectly developed that the crystallographer does not readily distin- guish or individualise the twin parts of which they are formed. m These specimens are of a dirty greyish or soapy colour: specific gravity equal to 2:40; and their chemical composi- tion, calcium 33, sulphuric acid 46, water 21. That these are still in course of formation in the manner which I have attempted to delineate there can be but little doubt. This supposition applies particularly to those places where fissures and cavities are formed in the parched mud, by the intense heat of the summer sun—the crystalising power having, in such spots, abundant room for operation, besides obtaining large supplies of sulphuretted hydrogen, derived from the decomposition of organic matters on the surface. In order to exhibit a more succinct view of the process which I have here endeavoured to describe, I have sketched out the opposite classification of details. (Vide plate. ) In the same basalt formation in other parts of Victoria I have found magnesite, opal, carbonate of iron, carbonate of lime, carbonate of strontium, mesotype, and steatite (soap- stone). The component parts of all these minerals are held in solution in common sea water, whence I am of opinion ' that they derive their origin from the enormous evaporation DD 234 The Data on which we have to depend and decomposition previously alluded to, of the sea water in the interior of the crater. I have received from Dr. Davey, to whom I had previously expressed my opinions on the foregoing subjects, a communi- cation coroborative of the chemical theory which I have advanced in the preceding pages. . Art. XX.—On What Data does the City of Melbourne depend for an Adequate Supply of Water from the Yan Yean Reservoir. By Davip KE. Wixi, Esq., M.D. SEVERAL papers having been recently read before the Society on the subject of the probable supply of water derivable from Yan Yean, I think it of great importance now to inquire upon what data we depend for obtaining this supply. I entertained the hope that the interesting questions treated of in the papers above referred to would have induced some of our scientific men to devote their attention to their eluci- dation; and I confess that I am rather surprised that no one seems disposed to investigate those questions further, although on a correct solution of.them must depend all our hopes of securing a sufficient supply of pure and wholesome water, which would contribute so largely to our health and comfort, and the failure of which would be so disastrous to the city. The question of evaporation, from its great importance in relation to the subject of this paper, claims our first con- sideration. Our meteorological experience in this colony is very limited, and little is known with respect to the annual rainfall in different localities. Judging from the tables that have been kept in Melbourne for some years, there is reason to believe that there is considerably less rainfall in Victoria than in England. The geological features of the country are unfavourable for the production of rivers, much of the rain water being held on the surface, and lost by evaporation. Our high temperature also conduces greatly to diminish the proportion of the rain that would otherwise reach the rivers. Thus the physical conditions of the country are very un- favourable for the preservation of water, and a great scarcity prevails in many districts. Hence the importance of arriving at a correct knowledge of the subject of evaporation, in order that, in our endeavours to preserve water in parts of the country that are ill-supplied, and to store it for the supply of For our Water Supply. 235 towns, we may adopt such measures as are really calculated to attain these ends. But the question of evaporation is especially important in relation to the subject. of this paper, as upon its decision depends at this moment the very important question, whether the Legislative Council ought to permit the Yan Yean works to be proceeded with, or to abandon them as a hopeless failure. It is to be regretted, however, that the subject of evapora- tion is very little understood, and its importance very little appreciated in this colony ; and it is not a little singular that Dr. Davey’s experiments and observations, which in any other country would be deemed sufficient to determine the rate of evaporation, are here regarded with distrust, and are thought to possess little practical value. If those, therefore, whose duty it is to proclaim the truths of science, and to vindicate their paramount claim to con- sideration inthe conduct of our great public works, hesitate to do so, can we wonder that the members of the Legislative Council should hesitate to interfere with matters involving scientific questions which they cannot themselves resolve ? But, independently of the great public importance of having this question of evaporation satisfactorily settled, there are other reasons which induce me again to bring this subject before you. The different papers that have been read on this subject contain opinions. observations, and experiments _of so opposite and conflicting a nature, that it is altogether hopeless to expect that the public will arrive at correct conclusions, unless the members of the Society can first agree among themselves. Surely it must be possible for a body of scientific men to determine the rate of evaporation in this country, and this is- really all that is wanted, in order to determine the success or failure of our water supply, derivable from Yan Yean. It is not too much to expect from the Philosophical Society that they should be able to inform the Legislative Council what loss will be sustained from evaporation in the Yan Yean Reservoir, and I should be sorry to think that a problem of so easy solution elsewhere should be deemed either difficult or impossible here. I trust, therefore, that it will not again be said of us that we are unable to decide this question. It surely will not be regarded as very complimentary to this colony, that-one of our daily newspapers should have pub- lished in its summary for England, that scientific men here were divided on the subject of evaporation, and on the defi- ciency that might result therefrom in the water supply of the city. 236 The Data on which we have to depend In difficult scientific questions to whom are the public and the Legislature to look, if not to the Philosophical Society ? And shall it be said that they have looked to us in vain? I am also induced on other grounds to bring this subject before you. It will not be forgotten that Messrs. Acheson and Christy, in their report on the Yan Yean Reservoir scheme, assumed that 10°69 inches of the rainfall of the Plenty basin would be available for the reservoir, while Mr. Hodgkinson clearly showed, by a reference to Mr. Charnock and Mr. Howard, who are the best recent authorities on the subject, that with a rainfall varying from 24 to 36 inches, the availabie rainfall for the average surface of England varies from 4°88 inches to 5°33 inches, the mean of which is 5:20 inches, with a mean rain of 30°6 inches. Thus these gentlemen have assumed for the Plenty basin an available rainfall more than double that of England. I had imagined, therefore, that Mr. Hodgkinson had demonstrated the fallacy of “the excessively small rate of evaporation assumed by those gentlemen,” and that their enormous estimate of the available rain was “utterly at variance with the recorded observations of all other meteor- ologists.” It appears, however, that they are by no means convinced of their error, and that they congratulate them- selves in the belief that they have arrived at the very same result with Mr. Hodgkinson, only by a different method. When the premises are so very opposite, it would be singular indeed if the conclusions were the same. T cannot, therefore, understand how they have deceived themselves into the belief that they have arrived at the same results with Mr. Hodgkinson, unless after this singular method. They assume double the amount of available rainfall that he does, and, at the same, time, they rely on Dr. Davey’s estimate of the evaporation from the reservoir, which is nine feet, while he rejects Dr. Davey’s estimate of the evaporation, and assumes five feet and a half from his own observations on a pond. But they altogether forget that, while they generously leave 9,386 gallons per minute for the use of the district, he only allows 500 gallons per minute, or an equivalent to eight inches in the reservoir, which is less than one-eighteenth part of what they allow; and they also forget that a mere coincidence in their results proves nothing in their favour; on the contrary, when similar results are obtained from data which are altogether dissimilar For our Water Supply. 237 and contradictory, it rather proves that both the premises and the conclusions are alike unworthy of confidence. I could readily understand how Messrs. Acheson and Christy might be right and Mr. Hodgkinson wrong, or vice versa, but I cannot imagine how both could be right. If Mr. Hodgkinson is correct in assuming five inches as the highest reliable amount of the available rainfall in the Plenty basin, then most assuredly Messrs. Acheson and Christy are egregiously wrong in assuming 10°69 inches, or more than double that amount; and if they are right in relying on Dr. Davey’s experiments and observations on evaporation, then, in like manner, Mr. Hodgkinson is wrong in rejecting Dr. Davey’s estimate of nine feet, and prefering his own of five and a half feet. IT have thought it necessary to notice this supposed coinci- dence, because it is very probable that many persons may be deceived by it. Most people are satisfied with merely looking to the results in any inquiry, without examining the data or calculations on which they are founded, and, in this instance, being so positively assured of a very abundant supply of water in two different ways, they will regard the supply as all the more certain on that account, and will be contented to have it either way. It is far more correct, therefore, to infer that both are wrong than that either is right, smce each denies and con- troverts the premises of the other; and it is altogether a fallacy to suppose that the similarity of their results will be of any avail in securing a more certain or abundant supply of water. And I trust to be able to show in this paper that no con- fidence whatever is to be placed either in theoretical esti- mates of the available rainfall of the Plenty basin, or in experiments on ‘evaporation conducted on ponds and water- holes, but that’ actual measurements of the river, and Dr. Davey’s estimate of the evaporation are alone to be depended on in deciding the important question whether the Yan Yean Reservoir scheme ought to be proceeded with, or altogether . abandoned. This leads me to notice the confusion that seems to arise from the use of the term “ available rainfall.” As applied to the Plenty basin it has no intelligible meaning, because many thousand acres, according to Mr. Hodgkinson, are so swampy that there is not only no available rainfall from them, but they evaporate and absorb a large proportion of the available rainfall of the rest of the basin, which is thus rendered no 238 The Data on which we have to depend longer available, although it forms a portion of the rainwater that is shed from the drainage area. Therefore the expres- sion available rainfall very incorrectly conveys the meaning that is intended, and is of little use in any scientific inquiry. To obviate this difficulty I have made use of the term “watershed” to signify the proportion of the rain that is shed from any given area or tract of country. This term has been ordinarily applied to the area or tract of country that sheds water, but this is so gross a corruption of the analogies of the English language, that I have avoided using it in this sense. At the time that my paper on the Failure of the Yan Yean Reservoir was published, I had only heard Mr. Hodg- kinson’s paper read, and, on its subsequent publication, I was much surprised to find that I had misunderstood him in several important points. While, therefore, I still regard his paper as a valuable contribution to practical science, I regret extremely to add, that I am compelled to differ from him very materially in some of the scientific data upon which he bases his con- clusions. Mr. Hodgkinson himself admits the necessity of throwing more light on the question of evaporation, “in order that definite conclusions relative to the probable supply of water derivable from Yan Yean might be arrived at;” and the extraordinary discrepancy of opinion that prevails on the subject clearly shows that, until this question is determined by scientific investigation, no definite conclusions can be arrived at. : I proceed now to consider what are the grounds upon which Mr. Hodgkinson bases his confident opinion, that there will be a very abundant supply for a population nearly three times greater than the present population of Melbourne, while I have myself found, by a strict method of investiga- tion, based on actual measurements of the river, that, after deducting the loss that is at present sustained from evapora- tion in the marshes, and the probable loss from evaporation " in the reservoir, according to Dr. Davey’s estimate, there will be no water for any population. Mr. Hodgkinson’s theoretical estimate of the watershed of the Plenty basin differs very little from my own. In dedu- cing the watershed from English data, I assumed four-and-a- half inches as the nearest approximation, while he assumes five inches. The difference therefore amounts to half an inch or one-tenth, which is equal to one foot in the reservoir. For our Water Supply. 239 How is it then that he is enabled to find a very abundant supply for 191,500? The following table gives Mr. Hodgkinson’s calculations reduced to feet, in the reservoir of 1 450 acres. Supply. Feet. In, 5 inches available rainfall over 623 ae a equal to 40,000 acres = 1l 6:16 7 inches ditto over drainage area of reservoir, equal to 3,000 acres ace 1 248 Rainfall on reservoir of 1, 400 acres 32 inches. Dew lO inches... ote nec oe i re 313) Total te -. 16 1:19 Demand. Feet. In. Amount lost in the swamps 2 5 Left to maintain the flow in the river, 500 gallons per minute ona 5S 8 Evaporation 66.6 inches over 1 400 acres se 5 4°33 Loss of flood water, and loss from absorption, equal to 6 inches over 1,400 acres a 5°79 Balance equivalent to supply 191, 500, at 40, gallons 7 0°52 Total ove we =: 15-1164 1. From the above table it will be observed that Mr. Hodgkinson assumes 5 inches over 624 square miles, instead of 44 inches over 60 square miles, and in this way gains 1 foot 7 inches. 2. He only leaves 500 gallons per minute, or 8 inches in the reservoir, for the use of the district, instead of 900 gallons, or 14 inches, and thus gains 6 inches. 3. He assumes that the whole of the available rainfall, less 500 gallons per minute, will be available for the reser- voir; whereas, I thought it unsafe to rely on any estimate deduced from English tables, and preferred an estimate based on the measurements, which leaves a balance of 1 foot 54 inches in his favour, and which I considered unsafe to rely on. 4, He assumes that 10 inches of dew will be onindeniseel on the surface of the reservoir, whereas I only allowed 2 inches, and in this manner he gains 8 inches. 5. He assumes the evaporation in this colony at 5 feet 6-6 inches, rejecting Dr. Davey’s estimate of 9 feet, and thus gains 3 feet 4 inches. These amounts will stand thus :— 240 The Data on which we have to depend . Ft. In. 1. Difference between 5 inch of rain over 624 square miles and 44 in.over60 sq.m. ... 1 7 2. i between 500 gallons and 900 gallons ... 3. 3 between my two estimates and not relied on hi S60 1 5h 4, 35 between 2 and 10 “Shite of dew nee 8 5 # between 5 feet 6°6 inches of evaporation and Q feet ... sae oe ono 3.4 Total a ae 7 62 Deduct loss of flood water, and loss from absorption... ae eae Act 6 Balance to supply 191,500 ine ee 7 O28 This table, then, exhibits the data on which depend all our hopes of an adequate supply of water from Yan Yean. If Mr. Hodgkinson is right in assuming these data, we shall have a very abundant supply, at least for our present wants. If, on the other hand, I shall succeed in showing that he is wrong, then, assuredly, the Yan Yean scheme will prove a failure, and we shall have to look elsewhere for our water supply. Having been induced, on public grounds, to investigate the points upon which Mr. Hodgkinson differs from myself, I trust that, in freely expressing my opinions on our points of difference, he will give me credit for simply wishing to arrive at the truth, and, as the question at issue isa iost momentous one for the public interests, both in a pecuniary and in a sanitary point of view, I trust that he will see no impropriety in my calling in question his opinions on subjects which he himself admits require further elucidation. 1. What reason does Mr. Hodgkinson assign for assuming 5 inches of the rainfall, instead of 4 inches or 6 inches? This is a very important question, as one inch over 625 square miles will supply 62,500, at 40 gallons per head, per day. ° The evaporation tables of Mr. Charnock, the Vice-Presi- dent of the Meteorological Society, and Mr. Howard, have, according to Mr. Hodgkinson, been chiefly relied on of late years, in Y estimating the proportion of the rain that is avail- able for water supply i in England. The available rain, according to Mr. Charnock, is 4°88 inches out of a rainfall of 24°6 inches, and according to Mr. Howard the proportion is 6°53 inches out of 36 inches. - Mr. Charnock’s observations have reference to a previous For our Water Supply. 241 well-drained soil in Yorkshire, Mr. Howard’s apply to the average surface of England; and it is interesting to remark that the observations of these gentlemen corroborate the previous observations of the late Dr. Thomson, of Glasgow, who estimated four inches ag the watershed of Great Britain, from observations and measurements of the Clyde. It is to be regretted that Mr. Hodgkinson has not clearly stated on which authority he has based his estimate of five inches, or the precise method by which he has arrived at this very important conclusion. He describes Mr. Charnock’s observations as the most ex- tensive and minutely accurate ever made in Britain, but they apply only to the Eastern Counties of England, where the rain- fall averages twenty-four inches. They also apply exclusively pervious well drained soil, and are, therefore, not applicable to impervious undrained lands, which receive and evaporate a large portion of the watershed from lands that are pervious and well drained. Mr. Charnock’s estimate is, therefore, too high for the average surface of England, and, with a mean annual rainfall of thirty-six inches, would give seven inches in- stead of five anda half inches, which is Mr. Howard’s estimate. It would be clearly wrong, therefore, to assume Mr. Char- nock’s proportion of available rain, for pervious and well- drained land in Yorkshire to determine the watershed of the Upper Plenty, where there are many thousand acres of im- pervious and undrained lands; and, in computing the pro- portion of the available rain for the average surface of England, Mr. Howard has no doubt made the necessary de- duction from Mr. Charnock’s estimate. Hence, while the estimate of the latter is one-fifth of the rain, that of the former is only one-sixth, and Dr. Thomson’s estimate for Great Britain, excluding dew, is one-eighth. The mean rainfall for Melbourne, for a period of six years, has been found to be 30°85 inches, and Mr. Hodgkinson seems to have adopted this proportion of rain for the Upper Plenty, as he regards the rainfall and dew taken together, as equivalent to thirty-six inches. Without any correction, therefore, for temperature or dry- ness of the atmosphere, Mr. Charnock’s proportion of the available rain would give 6:11 inches for the Upper Plenty, and Mr. Howard’s 4°73 inches. On what principle, then, does Mr. Hodgkinson adopt five inches to represent the watershed of the Plenty basin? He says, “I believe, therefore, that the proportionate amount of the rainfall available in the Upper Plenty district EE 242 The Data on which we have to depend is less than the English proportion. From the want of ex- tended meteorological observations taken in connexion with the Upper Plenty districts, or, what would have been much more satisfactory, a complete series of stream guagings to determine the annual discharge, ,the available rainfall of the district can only be analogically eliminated from the general data afforded by the most trustworthy English observations on evaporation, corrected for the average differences of tem- perature, for the various months in the year, in London and Melbourne, as given in the Statistical Register for Victoria. . Moreover, as wind and the hygrometrical state of the atmo- sphere exercise a marked influence over evaporation, inde- pendently of temperature, and as their action 1s more intense here than in England, some additional corrections must be applied to the English data for this increased action. Having made due allowance for all these contingencies, I have arrived at the conclusion that the total annual rainfall and dew at the Upper Plenty may be taken together as equi- valent to thirty-six inches, and that the amount thereof avail- able for the supply of the Plenty, in the present state of the natural surfaces, would be about five inches.” I entirely concur with the opinions expressed in the above paragraph, but, in adopting for the Upper Plenty district a larger proportion of available rainfall than is relied on for the average surface of England, Mr. Hodgkinson has alto- gether forgotten the principles which he has so ably incul- cated. He admits that the proportion of the rainfall in the Upper Plenty district ought to be less than the English proportion : Why does he not, therefore, adopt less than the Hnglish proportion? He admits the want of meteorological obser- vations, and that measurements of the river would have been much more satisfactory: Why does he not base his calcula- tions on the December measurements, making due allowance for the winter rains ? He tells us that his estimate of the available rainfall of the Upper Plenty District is only analogically eliminated from English data, corrected in a very complicated manner for temperature and dry winds. How is it then that he places such implicit confidence in an estimate so singularly enveloped in difficulties and uncertainties, and applied under novel circumstances to a pew country, with a totally different climate? And after all he has not made the corrections to which he attaches so much importance. He has adopted a less proportion of available rain than Mr. Howard’s, which For our Water Supply. 243 is relied on as correct for the average surface of England, and Mr. Charnock’s tables, which are alone applicable to previous well-drained lands, give only 6:11 inches as the proportion of available rain for the Upper Plenty District, and 6°11 inches, if duly corrected in the manner described by Mr. Hodgkinson, would give considerably less than four inches. I am at a loss, therefore, to discover by what method he has arrived at his conclusion that five inches of available rain represent the watershed of the Plenty basin. There is nothing in his reasoning to show why he should not rather have adopted four inches, but the reverse. If he has adopted Mr. Charnock’s proportion of 6:11 inches, then he has allowed 1°11 inches for all the contingen- cies to which he refers, and he has given no reasons why he should not rather have adopted Mr. Howard’s proportion, which gives, without any correction for temperature, only 4°73 inches, for the rainfall of the Upper Plenty. And, as it appears to me, Mr. Howard’s proportion for England, with adequate correction for difference of climate, is the only safe proportion from which to deduce the watershed of the Plenty basin. I have not had an opportunity of correcting either Mr. Charnock’s or Mr. Howard’s tables of evaporation, for differ- ence of temperature, but I have in the following tables corrected Dr. Dalton’s precisely in the manner explained by Mr. Hodgkinson, and Dr. Dalton’s estimate of available rain for England, which is 8°41 inches, when thus corrected gives exactly 4°54 inches as the proportion of available rain for our climate, without any correction for our very dry atmosphere, for which half an inch in addition may be very safely allowed. Thus the conclusion is inevitable that the tables of Mr. Charnock, and Mr. Howard, if similarly cor- rected would give a still less result. Admitting, theréfore, that Mr. Hodgkinson is right in assuming Mr. Charnock’s proportion of the available rain as applicable to the Upper Plenty district, I do not think that he has advanced any good reasons to show that the differ- ence in the evaporation of the two countries is so small, as to warrant the very small allowance he makes for the differ- ences of climate, in adopting five inches. a In my former paper I expressed a very decided opinion that no confidence could be placed in theoretical estimates of the watershed of the Plenty basin, deduced from English ‘data, at the same time, as a subject of scientific interest, rather than of any practical value, I assumed Dr. Dalton’s 244 The Data on which we have to depend estimate of 8:41 inches as the average watershed for Eng- land, and by correcting this amount for the difference of temperature, I concluded that four and a half inches would ese an approximation to the watershed of the Plenty asin. TaBLE I.—Showing the Mean Rain, the Mean Temperature, and the Proportion of the Rain evaporated, and the Watershed, and the Evaporation from Water in the different months in England, accord- ing to Dr. Dalton’s tables. EVAPORATION. Mean Rain. Mean Temp. From Land. From Water. Watershed. Inches. Degrees. ™ Inches. Inches. Inches. January ... ... 2°46 36 09 1-61 1:50 1:45 February ... ... 1:80 36°75 053 2°00 1:27 March... ... ... 0:90 42 65 0:62 3:50 0-28 Apriliesceee econ, 47-57 1.49 450 0:23 May ht! i. 8. 418 55°26 2:69 4:96 1:49 June ... ... ... 248 60-68 2:18 6:49 0°30 July ... ... 2. 4:15 63:17 4-09 5°63 0:06 August ... ... 3:55 62:75 3°38 6:06 017 September <5, @29 57-000 2:95 3°90 0°33 October ... ... 290 50°37 2°67 2°35 0:23 November... ... 2°93 43:12 2:05 2:04 038 December... ... 3°20 40-09 1-48 1-50 1-72 33 55 25:14 44-43 8-41 TaBLeE II.—Showing the Mean Rain, the Mean Temperature, and the Proportion of the Rain evaporated, and the Watershed, and the - Evaporation from Water in Victoria, deduced from Dr. Dalton’s tables, allowing the same evaporation to the same mean temperature in both countries. EVAPORATION. Mean Rain. Mean Temp. From Land. From Water. Watershed. , Inches, Degrees. Inches. Inches. Inches. January ... ... 136 | 67-94 1:34 8:00 0-02 February ... ... 095 67:31 0-93, 8-00 0-02 March oes) sa-2 960 63:92 1.57 649 0:03 April sent pee. Hole 60-56 2:75 * 6:49 0:38 May Aso) ode hare 54-91 2 36 4-96 1-31 June mre ete TAL 51:00 2:21 4-50 0-20 July aye eaait 743s) 49 34 1:88 450 0-30 August ... ... 361 50 66 3:32 4°50 0-29 September son 55°08 2:10 4:96 117 October ... ... 2:54 58-97 2:28 4:96 0°26 November... .,. 4:27 62-25 3°74 6:49 0:53 December... ... 1:86 66-29 1-83 8:00 0:03 a —— — —— _ 30:85 26 31 71-85 454 — ne ae — a i ee The above tables show that my conclusion is arrived at in the manner described by Mr. Hodgkinson, and if a further correction of half an inch be made for our drying winds, four For our Water Supply. 245 inches will represent the watershed as accurately as such a method of calculation will permit of. I think I am warranted, therefore, in concluding, that if we must place confidence in any estimate analogically elimi- nated from English data, we are not warranted in assuming a larger proportion of available rainfall for the Upper Plenty district that four inches. From Mr. Hodgkinson’s estimate of 11 feet 6°16 inches, we must therefore deduct one-fifth, or 2 feet 3°63 inches, which is equivalent to supply 62,500 at forty gallons per head per day. I also object to assuming sixty-two and half square miles as the area of the Plenty basin. Messrs. Acheson and Christy in their. report thought it safer to assume sixty square miles, and I followed their ex- ample in my estimate. This area has never been thoroughly surveyed, indeed the greater portion of the boundary line has never been visited ‘ by any surveyor, being covered with an impenetrable scrub, and many thousand acres, according to Mr. Hodgkinson, consist of swampy and undrained lands, which are not only useless as affording no watershed, but they evaporate the watershed of many more thousand acres which drain into them. As it was of great importance to arrive at a safe and reliable result in this investigation, I think Mr. Hodg- kinson erred in assuming sixty-two and half square miles, and for the reasons which I have assigned, I think it will be readily admitted that it was much more correct to have as- sumed sixty square miles as the area of the Plenty basin. On this account, therefore, I have to deduct from Mr. Hodgkinson’s estimate 4°60 inches in the reservoir, which is equivalent to supply 10,454. 2. Mr. Hodgkinson only allows 500 gallons per minute for the use of the district, and to maintain the flow in the river, and this is only equal to eight inches in the reservoir. Messrs. Acheson and Christy in their report allow twelve feet four inches for the same purpose ; so that they allow eighteen and half times the amount that he allows. They allowed this amount on the understanding that the Commissioners of Sewerage and Water Supply had entered into an arrangemeut with the resident population not to ab- stract more than one-half of the river, which was to be allowed to flow for twelve hours out of twenty-four. What will they say to the small amount accorded them by Mr. Hodgkinson? If his estimate of the discharge of the 246 The Data on which we have to depend river is correct, he only allows one-seventeenth part to remain, and abstracts all the rest for the reservoir. In this I feel persuaded that Mr. Hodgkinson has also erred, and there can be no doubt that if the Commissioners should ever attempt to carry out his recommendation they would find themselves overwhelmed with legal actions, and would be compelled to make very heavy compensation to all those whose interests might be affected by the loss of the river. In my estimate I allowed 900 gallons per minute, or one- third of Mr. Blackburn’s December measurement of the river at Yan Yean, and an idea of the smallness of even this amount may be got by reflecting on the circumstance, that, during the drought of 1851, when the Plenty had very nearly ceased to flow, Mr. Blackburn’s measurement in February gave 865 gallons per minute. I think, therefore, that it will be readily admitted that at least six inches must be deducted from Mr. Hodgkinson’s estimate on this account, and six inches will supply - 13,656. 3. Lhave stated that I have no confidence in theoretical estimates, and this is the reason that I preferred my estimate, that was based on measurement to that which I computed at four and half inches of the rainfall, merely as an approxi- mation from English data, hence I allowed the difference amounting to one foot five and half a inches in the reservoir, as a margin for casualties. In my preceding remarks it is, I think, clearly shown that I was wrong in assuming four and a half inches, and that I ought to have assumed four inches of available rain as the best approximation that can be arrived at from the most trustworthy English data. There is thus a difference of only 6-43 inches between the two estimates, and there can be no objection to leave this small amount for casualties, and, there- fore, it may be deducted from Mr. Hodgkinson’s estimate ; but as he has allowed six inches for loss of flood water. and from adsorption, I shall regard the 6°43 inches as an equivalent for his six inches. 4, I come now to consider the subject of dew. I explained in my former paper that very little dew could be condensed on the surface of water, and I allowed two inches only because it wa8 my firm conviction that, even without drawing off any water from the reservoir, there would often be very little in it; and when the water is very shallow, a small quantity of dew may possibly be condensed on the surface in very cold For our Water Supply. 247 ‘and frosty nights, and I was anxious that the reservoir should get every possible advantage. I must say, therefore, that I was greatly surprised to find that Mr. Hodgkinson relied on ten inches of dew for the re- servolr. I have looked in vain for any authority to bear out this extraordinary opinion respecting dew, and I feel assured that Mr. Hodgkinson could not have consulted the best authorities on the subject. In England, from four to five inches of dew are supposed to be condensed on the surface of the ground, and its produc- tion is easily explained, and well understood. But Mr. Hodgkinson obtains ten inches for the reservoir, by assuming that this amount of dew is condensed on the surface of water in this colony. This is a very important assumption, as ten inches in the reservoir will supply 22,727, at forty gallons, per head, per day, and 100,000 at nine gallons, which some allege is really all that is required for ordinary consumption. At this rate the dew condensed on the surface of the reservoir would suffice to supply Melbourne, with all its suburban towns and villages. Here, again, it is to be regretted that Mr. Hodgkinson does not say upon whose authority he assumes this enormous amount of dew. He certainly states that Mr. Thom, the eminent practical engineer of the Paisley Water Works, and the energetic promoter of the gravitation schemes of water supply in Scotland, considers that the evaporation in large reservoirs is counterbalanced by the condensation of dew, but this is only to be regarded as his individual opinion, and is certainly not based on accurate observation, or experiment. It is scarcely possible that Mr. Thom could have directed much attention to the subject of dew at the time that he uttered this opinion, and Mr. Hodgkinson himself shows that Mr. Thom’s statement is altogether inconsistant with the production of salt by the evaporation of sea water, which has been carried on for ages. Mr. Thom’s opinions, therefore, on scientific subjects are not very remarkable for their minute accuracy. __ Mr. Hodgkinson quotes his estimate of the available rain on which he relies for the Paisley Water Works, which is thirty-nine inches out of an annual rainfall of fifty-four inches. I can readily understand how low swampy ground, that is thoroughly intersected with catch-water drains, should yield a much larger amount of water than the whole rainfall, because 248 The Data on which we have to depend such lands often drain large tracts of country, but I cannot understand how Mr. Thom should imagine that fifty-four inches of rain fall in Paisley. This town is only seven miles distant from Glasgow, and, according to the meteorological tables, the rainfall for this city is twenty-one inches. Mr. Thom’s observations and experiments, therefore, could not have been conducted with much regard to scientific accuracy, when he computes the available rainfall at thirty- nine inches out of an annual rainfall of twenty-one inches, and they contrast rather singularly with Dr. Thomson’s observations and experiments, which give four inches of available rain out of twenty-one inches for the Clyde district. Since Dr. Wells published his well known Essay on Dew, his theory of its formation has been almost universally re-. ceived as correct. The production of dew occurs in the following manner. The quantity of aqueous vapour that can exist in the atmosphere depends entirely on temperature. During a clear calm night, all bodies that are fully exposed in the air become more or less rapidly cooled by radiation of heat from their surface. The air in contact with such bodies suffers a corresponding loss of heat, and, as soon as its temperature reaches the dew point, the moisture, which can no longer retain the form of vapour, is condensed in the form of dew. Thus, those bodies which radiate most heat and conduct least, condense most dew, and it is found that all bodies which are good conductors and good reflectors of heat from their surface, are bad radiators. The metals, therefore, condense dew very sparingly. Water, though a bad conductor of heat when applied to its surface, is from the extreme mobility of its particles, the most rapid conductor of heat and cold, when these are applied with due regard to its peculiar laws. Water in this sense may be regarded as strictly analogous to the metals, and, being a good conductor and reflector of heat, it is necessarily a bad radiator, and the dew is not formed on any surface whose temperature is not cooled by radiation below the dew point, which ranges from 5° to 20° below the temperature of the air. Unless, therefore, the surface of water be cooled by radiation below the dew point, it is quite clear that no dew can be condensed but its density, which varies with every change of temperature, and its fluidity operate to prevent any reduction of its temperature until the whole mass is similarly affected. The temperature of water is thus very slowly reduced by For our Water Supply. 249 radiation, because, as soon as the surface particles lose any portion of heat, their density is at the same time increased, and they sink to a lower level, being replaced by warmer particles from underneath. y Thus water differs most materially «from grass and other vegetable bodies whose power of radiation is very great, and which therefore cool very rapidly, and being very bad con- ductors, the heat that is lost by radiation is very slowly restored from the ground. Hence in clear calm nights they condense dew in great abundance. The greater the depth of water, the more slowly is its temperature diminished, as the surface cannot lose even 1° of heat until the whole depth has been reduced to the same temperature. And in this dry climate the dew point or point of saturation is often many degrees below the temperature of the air. It is thus easy to see that when there is a depth of more than a few inches of water no dew can be condensed on its surface. But we are not left to determine this point by reasoning on general principles. It is fortunately one that can very readily be determined by experiment. Dr. Wells found that a thermometer laid on a grass plot in a clear night, and in calm weather, sunk 6°, 8°, 13°, and even 20° lower than a thermometer hung at some height from the ground. This explains the rapid extraction of heat from the atmosphere in contact with the grass plot, and the copious deposition of dew on grass. But no such rapid re- duction of temperature has ever been observed in water placed under similar circumstances. The surface of the ocean and inland lakes retains a very uniform temperature, corresponding to the seasons, and suffers little change from the ordinary alternations of heat and cold during day and night; indeed the difference in the temperature of the ocean is scarcely perceptible. Tn temperate regions, the difference in the diurnal range of the thermometer in the air over the ocean is very trifling, rarely exceeding from 4° to 6°, while upon the continents the range often amounts to 20° or 30°, and between the latitudes of 25° and 50° the air is rarely warmer than the surface of the sea. And it is found by careful observation that while the temperature of the air over the land is rapidly cooled by the chilling influence of radiation during the night, the air over the ocean is several degrees colder than the surface of the water, and is therefore heated, not chilled, by contact with its warmer surface. FF 250 The Data on which we have to depend With cold winds the temperature of our inland lakes would be much more quickly cooled than by radiation; but for the formation of dew it is necessary that there should be scarcely any wind. It is also necessary that the water should abstract heat from the air, and not that the air should abstract heat from the water. Dr. Wells also clearly proved by his experiments that water fully exposed in a calm clear night in shallow vessels lost weight from evaporation, while dew was being largely deposited on the surface of the ground. An increase of weight from condensation of dew was only observed when the cold was so great that ice was formed, and in this case he found a slight increase in weight, but the existence of ice proved that the temperature of the water had been reduced far below the dew point. Tam not aware that any subsequent experiments have shown any inaccuracy in the experiments of Dr. Wells. It is to this uniformity in the temperature of water during day and night that our land and sea breezes are owing. During the day, the air over the land becomes heated, and a sea breeze is the result; during the night, the land is chilled by radiation, and the air being thus rendered much colder and heavier than that on the surface of the ocean, a land breeze is the result. In this manner, the extremes of heat and cold are very much moderated along the coast lines, and the climate is rendered much milder and more agreeable. There can be no doubt that like atmospheric currents will take place at Yan Yean. The heated surface of the sur- rounding ranges, during the day, will produce currents of cool air from the reservoir. During the night, the warmer air on the surface of the reservoir will give place to currents of cold air which has been deprived of its moisture by the chilling influence of radiation on the summits and slopes of the ranges. Mr. Hodgkinson’s theory, would, however, reverse the whole order of things. | If the surface of the sea and our inland lakes becomes during the night so much colder than the surface of the land as to condense double the amount of dew, we should have land breezes in the day, and sea breezes in the night; and our summer watering places would become inhospitable deserts. But as it is physically impossible for our inland lakes to lose from 5° to 15° of temperature by radiation during the night, so it is physically impossible for any dew to be con- densed on their surface. For our Water Supply. 251 And I feel persuaded that Mr. Hodgkinson could not have reflected sufficiently on the general principles which regulate the production of dew, otherwise he would certainly have omitted it altogether from his calculations, and his extreme confidence in a very abundant supply for 191,500, would have been considerably diminished. And there can be no objection to my deducting ten inches from Mr. Hodgkinson’s estimate, or an equivalent to supply 22,727. But there is another view of the subject equally fatal to the assumption of ten inches of dew. Mr. Hodgkinson has calculated the evaporation from the surface of the reservoir from English data. Now, these data represent the amount of water evaporated, as determined by actual measurement, without any reference to dew, the condensation and evapora- tion of which on the surface of the evaporating vessels are regarded as balancing each other. ‘Therefore, if ten inches of dew are assumed to be condensed on the surface of the reservoir, this amount must be added to the rate of evaporation deduced from English data. But Mr. Hodgkinson has not done this, he has allowed one inch for the three summer months in estimating the evaporation of the pond, but it does not appear that he has added nine inches for the other nine months. If he has done this, his estimate of the evaporation, ex- cluding dew, would be four feet 9°6 inches for twelve months, which it will surely be admitted is a very small allowance for this country, when Dr. Dalton’s estimate for Manchester is three feet eight inches, and Mr. Glaisher’s estimate for Greenwich is four feet two inches. If Mr. Hodgkinson, therefore, insists on retaining ten inches of dew in his estimate, he cannot object to add nine inches to his evaporation, which will thus amount to six feet 3°6 inches; but in this case the dew goes for nothing. 5. I have thus far endeavoured to show that very large deductions must be made from Mr. Hodgkinson’s estimate, ere we arrive at the amount that will be available for the supply of the city; and his estimate for 191,500 has been re- _ duced by an amount that would’ supply 109,337, leaving still sufficient for 82,163. I now proceed to consider what dependence is to be placed on the amount gained by Mr. Hodgkinson, from . prefering his own estimate of the evaporation from the surface of the reservoir, which is five feet 6°6 inches, to Dr. Davey’s which is nine feet. 252 The Data on which we have to depend This difference for an area of 1,450 acres is three feet four inches, and will suffice to supply 90,909, at forty gallons per head, per day. . The experiment on which Mr. Hodgkinson relies to prove the evaporation from the surface of water, during three of our summer months, has many singular features. It was conducted on a pond on the banks of the Yarra, very little above the sea level, and, therefore, in the most favourable position to receive a lateral supply from higher levels. Again, decomposed trap resting on stiff clay is ex- ceedingly favourable to retain the winter rains from higher levels, and to afford a large lateral supply to a pond fifteen feet deep. It cannot be doubted that a large amount of water may be supplied in this way. In many parts of Melbourne, and particularly at the lowest levels, it is almost impossible to prevent the cellars being filled with water. And, on the Gold-fields, the difficulties that the diggers have to contend with from influx of water at low levels, and in deep excavations, is well known. In selecting this pond for an experiment on evaporation, especially when the justification of a vast expenditure of public money depended on the result, it was incumbent on, Mr. Hodgkinson to show that it contained no springs, and that there was no other indefinite source of supply that could render the experiment fallacious. Springs are very often found in the ponds and water-holes that form the beds of many of our creeks. This is a well ascertained fact, and was therefore deserving of careful consideration. Tn some instances the springs gush out of the rocks above the water line, but, in general, they are principally distingished by the small apparent loss from evaporation in those ponds in which they exist. The difference in this respect is very remarkable, where there are chains of ponds all those without springs dry up during the summer months, aud I have been assured by old colonists, and residents on the Deep Creek, and other creeks, that many of the ponds have*from four to six feet of waterin them in November, and that they dry up completely in three or four months. Nor can this be accounted for by any loss that might be sustained from cattle drinking at them. Where there are continuous chains of ponds it would be difficult to understand how so many should be emptied in the same manner, and, For our Water Supply. 253 where all are equally accessible, how some should be emptied by cattle, while others, apparently, lose very little-water. And this objection cannot apply to my observations with reference to the Deep Creek, as the land is enclosed for cultivation. The water of these ponds is lost, therefore, either by evaporation, or absorption. Hither admission would be alike fatal to the prospects of the Yan Yean Reservoir. If so much water can be absorbed through the slate strata which form the bed of the Deep Creek, what reasonable grounds have we to expect that the same amount of absorption will not take place through the slate strata that form the bed of the reservoir ? It may be noticed that some settlers have great confidence in the Yan Yean scheme from observing that small artificial water-holes are often permanent in the summer months. If my reasoning is correct with regard to the effects of evaporation in this country, we may assume that the evapora- tion from the surface of water is nine feet, and that one-ninth of the rain may be relied on as the watershed. The extent of drainage area necessary to give a permanent supply of water to any pond can, therefore, be easily determined. With a rainfall of thirty-six inches, the ratio of the drainage area to the surface of the pond must be greater than eighteen to one, in order to secure a permanent supply. The ratio of the Plenty basin to the surface of the reservoir is about twenty-seven to one, but more than one-third of the watershed is not available for the reservoir, a large amount being lost in the swamps, and it being necessary to leave a certain proportion to maintain the flow in the river. Thus the ratio is practically reduced to eighteen to one, and there is, therefore, no more than sufficient to cover the evaporation. Reservoirs in England seldom exceed fifty acres, and they are generally much smaller, hence the loss from evaporation is very trifling, and the area of surface drained very large in proportion. The reservoir which supplies New York is 400 acres, with a depth of forty feet, and an unlimited command of water, the loss from evaporation is, consequently, not equal to one- third of that which will be sustained at Yan Yean. Had the Yan Yean Reservoir not exceeded 400 acres there would have been a saving of water equivalent to supply 188,500, at forty gallons per head, per day, with a depth of fifteen feet eight inches, instead of four feet four inches. 254 The Data on which we have to depend With thirty inches of rain the proportion would be twenty- one and half to one, and I have no doubt that, in all those cases in which settlers have obtained a permanent supply from arti- ficial water-holes, the ratio of the surface drained to that of the water-holes would be found to correspond to the proportions indicated above. Nor isit difficult to understand how, with a large area and steep slopes, a small pond might be supplied even from the summer rains. Thus, according to the evidence of gentlemen perfectly competent to describe what they have frequently observed, the evaporation from the ponds referred to is at least double what Mr. Hodgkinson observed in his pond. I might multiply instances of a very high rate of evapora- tion that has been observed both in this country, and else- where, by gentlemen whose credibility cannot be doubted, but, at present, I merely allude to the fact forthe purpose of showing that Mr. Hodgkinson is not justified in making so momentous a question as the rate of evaporation at Yan Yean, and the whole water supply of Melbourne, depend on asingle experiment on a pond, attended by many circumstances of doubt, and not conducted with that minute accuracy of detail which could alone command the confidence of scientific men, and without the most distant reference to the experiments and observations of others, who have arrived at very different results from his own. Mr. Hodgkinson estimates the area of his pond at one and a-half acres, and the area of the surface which it drains at nine acres. The ratio is, therefore, only one to six. And he assumes fifteen per cent. of the rainfall for the wa- tershed, which gives 3°6 inches for the three hottest months, from a rainfall of four inches. For the Plenty basin he has assumed 13°9 per cent. of the rain as available. In calculating the evaporation from the pond, the 3°6 inches might have been omitted altogether. If we refer to Dr. Dalton’s table we shall find that, with a rainfall of 4°15 inches in July, 4°09 inches are evaporated, leaving only 0:06, or one sixty-ninth part, to represent the watershed. Instead of 3-6 inches, therefore, Mr. Hodgkinson ought to have added only 0:34 inches, or one-third of an inch, as the watershed from the nine acres. Thus 3°26 inches must be deducted from the supply of the pond, and, therefore, from the evaporation, and there only remains 20°74 inches of evaporation for our three hottest months, or 6:91 inches for each month. For our Water Supply. 255 This is a very important deduction from Mr. Hodgkinson’s premises, as it proves one of two things. If his evaporation is right, then the 3:26 inches must be supplied from a spring, or from some distant and higher level beyond the limits of the nine acres. If, on the other hand, the rainfall of the nine acres is the only source of supply, then the evaporation for our three hottest months cannot exceed 6:91 inches. Either alternative would be sufficiently embarassing. Dr. Davey has shown ‘that the temperature of our three summer months, during last season, exceeded the temperature of the corresponding months in London, according to the meteorological tables of the Royal Society, by 10° of Fahr., and also that our dryness exceeded that of London by two and one-fourth to one. From these data we are warranted, ac- cording to the tables of Dr. Dalton, to compute our evapora- tion at nearly three times the English evaporation ; but, if we are to trust Mr. Hodgkinson’s experiments in the pond, our evaporation will only exceed Dr. Dalton’s estimate for June by less than half an inch for each of the three months. And, if we further deduct one inch of dew, which Mr Hodgkinson has allowed for the three summer months, his estimate of the evaporation accurately deduced from his own premises, will almost exactly equal the English evaporation. ‘ The watershed of the nine acres for twelve months, cal- culated at fifteen per cent. of the rainfall, is equal to 27:76 inches, which, added to the rainfall of 30-85 inches, gives four feet 10°61 inches, as the available supply for the pond, but Mr. Hodgkinson’s evaporation is five feet 6-6 inches. How is it then that the pond does not dry up? And how shall we account for a depth of ten feet of water in the summer months? It only receives four feet 10°61 inches, and it eva- porates five feet 6.6 inches, the difference amounting to 7-99 inches. The conclusion is inevitable that the balance is made u from a spring, or some other source independent of the rainfall. : And, this being proved, who is to compute the amount of water thus supplied? or what confidence can be placed in an estimate of the evaporation based on such uncertain data? Thus, to determine the amount of this lateral supply is purely an impossibility, and to assume the amount is to beg the whole question. After the explanation given above respecting dew, it will be of no use to allege that the balance is made up in this way. If nine inches of dew are assumed to be condensed on the 256 The Data on which we have to depend pond during nine months, the same amount must be added:to the evaporation, and, therefore, nothing is gained. It is a singular fact that all our hopes of deriving an ade- quate supply of water from Yan Yean, at this moment, de- pend on Mr. Hodgkinson’s estimate of the evaporation derived from the pond, and it must be regarded as still.more singular that his own data, on which he relies to prove the correctness of his estimate, have furnished the best proof of its fallacy, by clearly showing that the pond is supplied from springs. In calculating the evaporation of the other nine months, Mr. Hodgkinson has recourse to English data, and computes the amount by “correcting these for the average differences of temperature for the various months of the year,” and by “ applying a slight additional correction for the frequent oc- currence of dry winds.” He does not say whose tables he has employed for this purpose, but, in order to illustrate the principle upon which he proceeds, I have added to the foregoing tables the evapo- ration from the surface of water af Manchester, according to Dr. Dalton’s experiments, and also the evaporation from the surface of water in this colony, dedtfced from the English evaporation by allowing the same proportion to the same mean temperature in both countries. For our three summer months I have adopted Mr. Hodg- kinson’s estimate of eight inches, andthe result, as may be seen by reference to the tables, gives five feet 11:85 inches. - Thus it is seen that the corrections for temperature alone, give 5°25 inches more than Mr. Hodgkinson allows, after having made all the additional corrections that are necessary for our very dry atmosphere, and the more “intense action” of our very dry north winds. But it is not necessary to adopt Mr. Hodgkinson’s estimate in order to get eight inches of evaporation for each of our three summer months. Dr. Dalton’s tables give 6°49 inches as the evaporation for June in Manchester, and they also point out the method for correcting the evaporation for temperature and dryness, by a simple formula. Now, Dr. Davey has shown that the temperature of our three hottest months is 10° higher than the temperature of the three corresponding months in London, according to the tables of the Royal Society. Thus, our increased tempera- ture alone, without reference to dryness, would give 9°73 inches as the evaporation from the surface of water deduced For our Water Supply. 257 from English tables, the rate of evaporation being doubled with every increase of 20° of Fahr. But Dr. Davey has also shown that the mean dew-point of our hottest months is 50°, thus showing a dryness of 19°, or in the proportion of two and one-fourth to one compared with London. Now, according to the formule of Dr. Dalton, and Dr. Ure, 9°73 inches corrected for our dryness, would. give 16°22 inches for each month, or 48°66 for three months. The above table shows that the English evaporation for the other nine months, corrected for temperature alone, is 47°85 inches. As there are no correct data to show our relative dryness for these months, this correction must be omitted, but, even without this, the rate of evaporation deduced from English tables, in the manner described by Mr. Hodgkinson, amounts to eight feet 0°51 inches. Thus, if we make some additional corrections for our greater dryness for the nine months, and for the more “ intense action” of our dry winds, I do not see how Mr. Hodgkinson can escape from the conclusion, even according to his own method of calculation, that the evaporation from the surface of water in this colony is little short of nine feet. In my former paper I stated, on the authority of the Year Book of Facts for 1854, that Mr. Glaisher had estimated the evaporation at Greenwich at five feet; I have now ascertained from his Hygrometric Tables, that his estimate is four feet two inches, so that Mr. Hodgkinson’s estimate of five feet 6°6 inches for Melbourne, is very little more that Mr. Glaisher’s for Greenwich, and the Greenwich evaporation when corrected f or our higher temperature, would give six feet three inches without any corrections for dryness and winds. But why does he resort at all to English data in order to deduce our evaporation in a troublesome and unsatisfactory manner? Had Dr. Dalton any peculiar method of determin- ing the evaporation at Manchester different from that adopted by Dr. Davey in Melbourne? [If it is correct to deduce our evaporation from Dr. Dalton’s evaporation for the nine months, why is it incorrect to depend on Dr. Davey’s evaporation for the three months? Both these gentlemen have adopted precisely the same method of experimenting in determining their respective rates of evaporation. Dr. Dayey’s experiments, which were conducted daily during the period referred to, are in every respect similar to GG 258 The Data on which we have to depend those which are everywhere else depended on for ascertaining the rate of evaporation, and they were conducted with a degree of care and minute accuracy which it would be difficult to exceed. He carefully measured, in a graduated vessel, each portion of water that was exposed to evaporation, and thus every drop that was evaporated was accurately registered. Those gentlemen who question the accuracy of his results ought to point out in what manner his experiments differ from Dr. Dalton’s or Mr. Charnock’s, and how it is that his are fallacious while they place implicit confidence in theirs. The method commonly adopted for the purpose of throwing doubts on the accuracy of Dr. Davey’s results is to compare his scientific experiments with observations on ponds and waterholes. But enough, I trust, has already been said to show that a more fallacious test could not be applied. But, if this question must be decided by observations on ponds, I have mentioned other observations which give nearly double the amount of Mr. Hodgkinson’s estimate, and I do not see in what manner he can dispose of these. And I my- self measured, with the greatest care, the evaporation from the surface of a pond in the month of February, and found that there was a loss of exactly eleven inches in twenty-eight days. Now, can Mr. Hodgkinson point out any source of error in this experiment? unless it is that I omitted to add anything for rain, or dew, or lateral supply, for all of which he has made a very liberal allowance in his experiment, but this would have added to, not diminished the rate of evapora- tion. The only scientific objection that has been urged against Dr. Davey’s estimate being applied to the Yan Yean Reser- voir is the great extent of surface. It is thought that the air will become so saturated with vapour that the rate of evapora- tion will be very much diminished. There can be no doubt that inthe case of the ocean this objection would have considerable weight, though, even there, extended observations show that the air is very rarely near the point of saturation; but with regard to the Yan Yean Reservoir, I feel quite certain that the effect which extent of surface would have in retarding evaporation has been greatly exaggerated, Being surrounded by an amphitheatre of hills, it may, to a certain extent, be protected from strong winds; but, on the other hand, this physical conformation will render it more liable, in calm weather, to atmospheric currents resulting from the unequal effects of solar heat on the surface soil of the Seca toe yt For our Water Supply. 259 hills, and on the water of the reservoir. The latter will preserve a very uniform temperature, while the former will be subject to great diurnal alternations of heat and cold. Thus the vapour that is formed on the surface will at ali times be quickly removed, and replaced by currents of drier air. And it is important to notice, that the amount of water evaporated, other things being equal, is exactly in proportion to the surface exposed; and it it is not difficult to see” that when the water is agitated with winds and currents, the extent of evaporating surface will at least be doubled. ’ But, independently of winds and atmospheric currents, it appears to me that those gentlemen who urge this objection have altogether overlooked the law of diffusion, which applies equally to vapour and all other gaseous bodies. In a still atmosphere, it is true that diffusion will operate more slowly than when aided by currents; but asthe vapour of water is lighter than air at the same temperature and pressure, in the proportion of 62 to 100, its diffusive power is very great, even in a perfectly still atmosphere; and it may be confidently concluded that the hygrometric condition of the atmosphere and the tension of its vapour will not be materially affected by the evaporation from the reservoir, which, notwithstanding its great extent, is very limited compared with the ocean. And, with our Australian atmosphere, which is so re- markable for its dryness, and with the rapid diffusion that will result therefrom, it would be very unwise to calculate upon a greatly diminished rate of evaporation in the reservoir. In his estimate of nine feet of evaporation for the reservoir, Dr. Davey has made ample allowance for the retarding effects of extent of surface. His observations have only extended over four months, and the evaporation for these months is as follows :— Inches. January, by approximate data noo nop nfo 21°710 February, by daily observations ... O66 ike ... 23°630 March o 3 a nae ae ie 15470 April es S ats bos re --« 10:000 ‘ . With respect to these amounts, as Dr. Davey is absent from town, and as Mr. Brough Smyth thinks that he intended to make some corrections on account of the evaporating vessel used in January and February, he advises me to assume at present, only eighteen inches for December, January, and February; the amounts for March, and April, he thinks, do not require any corrections. Now, in computing nine feet as the evaporation from the . 260 Remarks on the principal Rocks reservoir, it is only necessary to assume sixteen inches for each of the three summer months, therefore, Dr. Davey has allowed a large deduction from the true evaporation, to compensate for the extent of the reservoir, or any other accidental canse that might operate to retard the evaporation from the surface. : What possible reason, or excuse, then, can be given for re- jecting Dr. Davey’s estimate of nine feet? According to my judgment the conclusion is irresistible that his estimate 1s confidently to be depended on, and I feel warranted in de- ducting the three feet four inches from Mr. Hodgkinson’s estimate, which is equivalent to supply 90,909. Having thus stated the points of difference between myself and Mr. Hodgkinson, and which constitute the data on which we depend for our water supply, and having shown that they _ are not based on correct or scientific principles, and are, therefore, unworthy of your confidence, and that, on a thorough investigation of the subject, there are no data to show that there will be any water for the city derivable from Yan Yean, I have little to add. T shall submit, therefore, that the Philosophical Society has now 2 very important duty to perform; aduty to themselves, as the interpreters of science in this colony; a duty to the Government and the Legislative Council, who look to them for a scientific opinion to aid them in the decision of the question, if it be proper to allow the Yan Yean works to be proceeded with; and a duty to the public, whose health, and comfort, and pecuniary interests are so seriously involved in the success or failure of the Yan Yean Reservoir scheme: and I trust that the Philosophical Society will no longer hesitate to pronounce an opinion on the subject. Art. XXI.—Remarks on the favourable Geological and Chemical Nature of the principal Rocks and Soils of Victoria, in reference to the production of ordinary Cereals and Wine. By Cuement Hopexinson, Esq, C. E., Survey De- partment. Havine visited the four principal Australian Colonies and been connected with agricultural pursuits in New South Wales, I have long held the opinion that Victoria will eventually produce more wheat and wine than any other Aus- ' tralian Colony; partly, because this territory contains the And Soils of Victoria. 261 largest proportionate extent of land adapted for agriculture, and partly in consequence of the geological and chemical influences that have either tended to render much of the best soil here capable of withstanding, without renovation for a long series of years, the, most severe cropping, or else established a condition of soil most favourable for the produc- tion of wine of superior quality. For a considerable period, Victoria, notwithstanding the gold discoveries, has been supposed to offer less inducements for the settlement of bona fide working farmers than some of the other colonies, more especially South Australia; and I believe that the great extension of agriculture in that pro- vince has resulted less from the fertility of the land, and the facility of its acquirement in small sections, than from the numerous class of agriculturists, with small capital, who have been attracted to South Australia in consequence of the superior advantages it has been supposed to offer to small farmers. The most remarkable characteristic of the physical confi- guration of this colony, when compared with that of any other Australian colony, is the great prevalence here of volcanic rocks and clay slates. Sir Charles Lyell has noticed the general fertility of soil produced from the disintegration of volcanic rocks, but in Australia the fertility of soil thus produced has often been found most extraordinary. For instance, in New South Wales at Prospect Hills, where a small dyke of trap traverses the sandstone, some of the soil derived from the trap was brought into cultivation before the close of the last century, and has ever since given good crops without manuring; yet this land does not display any symp- toms of exhaustion. On the trap formation at Ilawarra, I have heard of sixteen successive crops of wheat, having been taken off the same piece of ground, without the last crops having exhibited any falling off, as regards quantity or quality. Even the natural vegetation on soil derived from volcanic rock in Australia, is, almost constantly, more luxu- riant than on other soils. This is especially noticeable in the Blue Mountains, wherever the thick stratum of sandstone is displaced by dykes of trap; thus on the basaltic slopes of Mount Hay are found enormous trees, ferns, and luxuriant creepers, whilst all the surrounding mountain ranges and gullies, are only partially clothed with low scrubs. There is also a sudden and startling change on entering the trap for- mation at Ilawarra, from stunted eucalyptus and low bushes to lofty palm groves and semi-tropical vegetation. In this 262 Remarks on the principal Rocks colony the natural vegetation attains also its maximum luxu- riance on those mountain ranges and gullies displaying the older volcanic rocks; thus on the eastern slopes of the Dan- denong Mountains, and on some of the ranges of the Port Otway District, which are thug geologically constituted, the enormous dimensions and altitude of the trees are not sur- passed in any part of the globe. On the north-west coast of New Hoiland, Sir George Grey particularly noticed during his explorations there, the remarkable contrast between the refreshing aspect of the vegetation’on the few basaltic hills he encountered, and that of the general surface of the coun- try traversed by him. It would therefore, seem, from the experience of more than half a century in New South Wales, that some of the soils derived from the disintegration of volcanic rocks in Australia are able to bear, without apparent exhaustion, an amount of cropping that has, in America, been found by experience, sufficient to wear out some of the most fertile soils there. Soils displaying the extraordinary power of maintaining, without artificial renovation, their fertility unimpared by cropping, for a long series of years, are of very rare occur- rence in Europe, although a few very remarkable instances are recorded by Sprengel. : Thus he states that a field near the village of Nebstein, in Germany, has been cultivated for the last one hundred and sixty years without manure, and without being allowed to be fallow, and yet has produced good crops. The analysis of soil formed by the disintegration of volcanic rock analogous to that near Melbourne, has been found to be as follows :— Silica a ike ate Me 83°642 Alumina sae Be hae .. 3978 Protoxide and Peroxide of Iron a 5312 Peroxide of Manganese ... a0 .. 0:960 Lime a Baa ba My) 1:976 Magnesia 300 dia 4 ... 0°650 Potash in combination with Silica on 0:080 Soda in combination with Silica ... xan 0-145 Phosphoric Acid in combinatien with Lime 0-273 Sulphuric ditto ditto ... a trace Humus, soluble in Alkaline Carbonates 1:270 Chlorine de ps fh ... a trace Humus_... 5h Ate 30 0°234: Nitrogenous Matter 208 308 « -1:480 The cultivation of wheat abstracts from the soil a larger proportionate quantity of silicate of potash than most agri- cultural products, and also demands an average quantity of And Soils of Victoria. 263 the phosphates. Now, although volcanic rock, especially if augite predominate in its composition, may occasionally con- tain a less proportionate quantity of the alkalis, or even of the phosphates than some other rocks, yet, the greater intensity of the disintegrating action generally observable in soil derived from volcanic rock would often furnish so large and continuous a supply of the chief inorganic constituents required by cereal crops, as to. render the renovation of the soil, by disintegration still going on therein, quite equivalent to the abstraction of inorganic matter by incessant cereal erops. In this way only can I account for the inexhaustible soils already alluded to, at Prospect and Illawarra. But in Victoria we possess extensive tracts of land, not yet brought under cultivation, whose soils seem to me to be under precisely the same conditions of derivation and disin- tegration as the soils of those favoured, but very limited localities in New South Wales; and much of this land in Victoria consists of well-grassed plains, easily brought under cultivation. I admit that the soil in connexion with the recent lava, north of Melbourne, is not always rich, but may yet, on the whole, be pronounced so far good as to justify the opinion I now venture to submit to you, that in Australia, soils derived from the disintegration of volcanic rocks are more generally fertile than those connected with aqueous or plutonic rocks. As the available surface of Victoria embraces a much ™ greater extent of soil thus derived, than that of any other Australian Colony, I have therefore concluded that the natural advantages of Victoria, in reference to the extensive and successful production of ordinary cereals, greatly preponderates over those of her neighbours. In South Australia the only volcanic district worth noticing is that around Mount Gambier on the confines of the colony. In Tasmania volcanic rocks are more prevalent, but are very frequently associated with steep densly wooded surfaces. In New South Wales the sandstone of the central counties is, in a few localities, displaced by trap dykes, as already me- tioned; in the northern part of that territory, the volcanic rocks are mostly confined to densly wooded mountain ranges. But if the disintegration of volcanic rocks in Victoria has rendered so much surface pre-eminently adapted for corn crops, the disintegration of another class of rock very prevalent near Melbourne,—clay slate,—has tended to produce much soil that would prove, in the very highest degree, favourable not only to the growth of the vine, but also to the production of wines of very superior quality. 264 Remarks on the principal Rocks The paramount influence of the constituents of the soil of a vineyard on the quality of the wine produced is well known. In some of the best wine districts of France it is no uncommon occurrence to find two adjacent vineyards both planted with the same kinds of vine, similarly cultivated, and where all the operations of the vintage are conducted in precisely the same manner, and yet the wine of one of these vineyards remains totally distinct as regards quality and _ flavour from the wine of the other; such variations being entirely due to differences in the soils of the respective vine- yards. It is also known that the application of certain kinds of manure to vines will cause serious deterioration in the quality and flavour of the wine produced in the following season; and sometimes the pristine quality and flavour cannot be regained for several vintages. The composition therefore of any rock whose disintegration has formed the soil of any vineyard must obviously exercise a most important influence on the quality of the wine derived from the vineyard. Now according to the best authorities I have been able to refer to, the disintegration of clay slate produces a soil of unusual excellence for vineyards. . Thus, Dr. Adams in his remarks on the rocks and soils of the celebrated Constantia Vineyard at the Cape of Good Hope, has observed how well the vines thrive in a soil produced by the decomposition of clay slate and mixed with the fragments of it. Humboldt has stated that the vines of the schistose ranges, in the valley of the Rhine, produce most excellent wine ; and I am aware that the best wines of the province of Anjou, in France, are obtained from vines grown on the same formation. Albertus Magnus has also observed that the vine thrives un- commonly well in earth mixed with fragments of slate. Some of the clay slates and schists near Melbourne are accompanied by a fertile soil adapted for ordinary agriculture or vine culture; but more generally the schistose ranges in the basin of the Yarra, eastward of its tributary the Plenty, are not sufficiently accessible to be available for ordinary crops, and are sometimes very barren. But I have occasionally encountered within twenty-five miles of Melbourne, ranges of dark clay slate that have furnished by disintegration. soil now only supporting a dense stringy-bark forest, yet which seems to me to be of the same nature as the soil of the cele- brated vineyards on the dark-coloured schists of the Rhenish Mountains. Very few of the vineyards of the counties of Cumberland and Camden, in New South Wales, have been established on Ss and Soils of Victoria, 265 such suitable sites for vine culture with the view to the fabri- cation of wine, as could, in this colony, be selected, within half a day’s walk from Melbourne, among the stringy-bark ranges already alluded to, and yet which, if now put up for sale, would be declined at the upset price. Itis therefore not impossible but that, before the close of the present century, Melbourne will have in its vicinity flourishing vineyards, some of which might occupy ground now considered, notwith- standing its proximity to Melbourne, valueless even for grazing purposes. —aie ee . Soy ah th hie) Se wks AW eh SHAE ae rth neta te po’ TRMttr et soc 1 Vie, salopae Jae Dawe prec esc iis sitenree Bi: pie. kee yap ad, Pa) brslghy foakevadhy sas bara baa iit: sees) ode acated: ied bad “ahve see's MORE Peas mist Re Weed rte RARE OR yy Eee HOt 1 ria vine ey 5.07 ind thd iy janitor der wikwess anal: lonaha F ap me piss at ra A i eel hot® PROCEEDINGS. PROCEEDINGS, &c. August 12th, 1854. Av THE FIRST GENERAL MEETING oF THE SocIETY, The President delivered an Inaugural Address. Dr. Ferd. Mueller read a paper:— Definitions of rare and hitherto undescribed Australian Plants, chiefly collected within the boundaries of the Colony of Victoria.” Presents acknowledged :—Fossils and Minerals from Geelong, Capt. Clarke, R.E. Fossil Plants from Cape Patterson, R. B. Smyth, Esq. Fossils from Mount Eliza, and adjoining district, A. Selwyn, Esq. Botanical Specimens, Dr. Ferd. Mueller. September 10th, 1854. Montuty Merrtine. Dr. Ferd. Mueller in the Chair. The Minutes of the last Meeting were read and confirmed. New Members admitted since the last Meeting :—The Rev. Dr. M. Goethe, Dr. A. Davey, John G. Foxton, James Paterson, Balfour Stewart, Esqs., and Dr. J. Black. S. Wekey, Esq., the Honorary Secretary, reported that he had laid before the last Meeting of the Council, a project for the organi- sation of exploring expeditions for the purpose of “ prospecting ” in different parts of the Colony, with a view to the development of its various resources, such as Auriferous Fields, Coal, and Minerals generally, and the Vegetable Productions. Owing to the import- ance of the subject, he was instructed to lay it before this Meeting. The project being entertained, it was referred to a Sub-Com- mittee, consisting of Dr. Mueller, Dr. Iffla, R. B. Smyth, Esq., and the Honorary Secretary, for details. b rt Proceedings. Balfour Stewart, Esq., read a paper on “Certain laws observable in the mutual action of Sulphuric Acid and Water.” He remarked that these two liquids combined in any proportion, and seemingly without any reference to chemical equivalents; but he would ex- hibit a method by which a distinct reference to their equivalents might be discerned. If we calculate the specific gravities of the different strengths in Dr. Ure’s table, viewed as composed of strong sulphuric acid of the specific gravity 1°8485 and water, we shall find that these are less than the observed specific gravities given by Dr. Ure. This condensation is due to chemical action, and its proportion is greatest for strength 73, which denotes a chemical compound of 1 equivalent sulphuric acid, and 2 equivalents of water. But we may take any strength of mixture as our standard, and view all other mixtures as composed of this mixture, and sulphuric acid, or the same mixture and water according as they are stronger or weaker. In this way, adopting the specific gravity of the standard given by Dr. Ure, we have a different set of calculated specific eravities for each different standard, and consequently a different proportional condensation. If we take the strength 40, 45, 43 as standard, we are pointed to the maximum of condensation at strength 73 as before, but if we take as standards strengths 40, 55, 53, we are pointed to a maximum of condensation between strength 84 and 85 which denotes one equivalent of sulphuric acid, and one equivalent of water. In like manner if we take as standard strengths 40, 38, 45, we are pointed to a maximum at strength 82, which probably denotes a compound containing 5 equivalents of sul- phuric acid, and 6 equivalents of water. Mr. Stewart, in con- clusion, observed that he did not so much regard the immediate results of this investigation as-the means it afforded us of tracing definite chemical action in cases of solution as well as perhaps in alloys and amalgams, The Rev. A. Morison observed that the subject had no con- nexion with the Atomic theory, as Mr. Balfour Stewart seemed to imply, nor is it apparent that any result of importance would be gained by the attempt. It is the production or suggestion rather of a mathematical than a chemical mind. In it, the mathema- tician subordinates the chemist, whereas the reverse is the order of the practical man. Mr. Stewart agreed that there was no electric affinity in the combination of sulphuric acid and water. The object of the paper was to show that a change was effected by solution, and that that change was regulated by the principles of the Atomic theory. In chemistry the compounds are very often entirely different from either of their in&redients, often slightly different; but in cases of solution it has been the habit to consider that no chemical action has taken place at all. It is not necessary that the compound should possess different optical properties, or differences which are obviously apparent in order to constitute chemical action. The test of contraction in volume is surely quite legitimate. Proceedings. ll R. B. Smyth, Esq., said with regard to the maximi of densities, which it was the object of Mr. Stewart’s paper to elucidate, he would beg to refer to the following observations of Dr. Ure, who computed the tables on which that paper was founded. “Dilute acid having a specific gravity — 1°6321 has suffered the ereatest condensation; 100 parts in bulk have become 92:14. If either more or less acid exist in the compound, the volume will be increased. What reason can be assigned for the maximum condensation occurring to this particular term of dilution? The above dilute acid consists of 73 per cent. of bil of vitrol, and 27 of water. But 73 of the former contains by this table 59°52 of dry acid, and 13°48 of water. Hence 100 of the dilute acid consists of 59°52 of dry acid + 13°48 x 3 — 40.44 of water — 99°96; or, it is a compound of one atom of dry acid, with three atoms of water. Dry sulphuric acid consists of three atoms of oxygen united to one of sulphur. Then each atom of oxygen is associated with one of water, forming a symmetrical arrangement. One may therefore infer, that the least deviation from the above defi- nite proportions, must impair the balance of the attractive forces, whence they will act less efficaciously, and therefore produce less con- densation. . “The very minute and patient examinations which I was induced to bestow on the tables of specific gravities, disclosed to me the general law pervading the whole, and consequently the means of inferring at once the density from the degree of dilution, as also of solving the inverse proportions.” Subsequently Dr. Ure gives clear directions for ascertaining the dry acid and sulphuric acid in any dilute acid of given specific gravity. As Dr. Ure’s tables are dependent upon the nicety of his apparatus, and care in truly estimating the various influences to which experiments with sulphuric acid are liable, we cannot im- plicitly rely upon their accuracy. As a foundation for calculation, such as Mr. Stewart’s, he held them to be objectionable. Sulphuric acid, as Dr. Ure observes, has only a small specific heat, and is affected by changes of temperature, which would scarcely be recognised by the most delicate instruments. Mr. Smyth considered the subject to be highly useful in a ~ scientific point of view, if tested by actual experiment. Presents acknowledged :—Fossils and Minerals from Mount Ida, M‘Ivor, Capt. Clarke, R.E. September 18th, 1854. SpreciaL GenerAL Merzetine. The President in the Chair. The Minutes of the last Meeting were read and confirmed. The Honorary Secretary read the following Report of the Sub- Committee, appointed at the last meeting, to consider the details of the project for organising exploring expeditions:— iv Proceedings. “Your Committee, appointed to consider the organisation of: Ex- ploring Expeditions, begs to propose that the following resolutions be adopted to that effect :— “That the Society shall organise “exploring expeditions, which shall be despatched from time to time, for the purpose of discovering new auriferous fields, coal, &c., and to collect additional information respect- ing the various mineral and vegetable resources of Victoria. ‘‘That each exploring party shall be furnished with special instruc- tions by the Society. ‘ That the reports of such expeditions shall form part of the Trans- actions of the Society, and be published for general information. ‘‘That in addition to the individual exertions of the members, the whole proceeds of the first Transactions of the Society shall be appro- priated to this purpose, and the half of each subsequent publication. “That any further funds which may be required to carry out this object shall be raised by public subscription. ‘‘That the President be requested to communicate with His Excel- lency the Lieutenant-Governor, as patron of the Society, requesting him to give his assent to the enterprise.” The Report of.the Sub-Committee was unanimously adopted. R. Brough Smyth, Esq., read a paper on the “‘ Comparative value and durability of Building Materials used in Melbourne.” S. Wekey, Esq., the Honorary Secretary, said that the accumu- lating business of the Society rendered it scarcely practicable that one person (having other engagements) should perform the duties of Secretary, and moved accordingly :— “That R. Brough Smyth, Esq., be elected Honorary Secretary, to act in concert with himself.” The motion was seconded by Dr. S. Iffla, and carried. Presents acknowledged :—Thomas Adair, Esq., Mineral and Botanical Specimens. Capt. Ross, R.N., Shells from Sealer’s Cove, Native Bear. R. B. Smyth,- Esq., Shells from the Barbadoes, &c. October, 21st, 1854. Montuty Msrrtince. The Rev. A. Morison in the Chair. The Minutes of the last Meeting were confirmed. New Members admitted since last Meeting:—His Honor the Acting Chief Justice, Redmond Barry, Esq., the very Rev. Dr. Geoghegan, the Rev. James Clow, Edward Wilson, J. H. Brooke, Fred. Acheson, Clement Hodgkinson, and L. Becker, Esqs. Wm. Blandowski, Esq., read a paper,—‘ Personal Observations during an Excursion through the Central Parts of Victoria.” Proceedings. Vv November 14th, 1854. Montuty Mezrine. In the absence of the President, R. Hades, Esq., M.D., was voted to the Chair. The Minutes of the last Meeting were confirmed. S. Wekey, Esq., Hon. Sec., announced to the Meeting, that in order to meet the wishes of several of its Members, it was resolved at the last Meeting of the Council that the Monthly Meeting of the Society should be held on the second Tuesday of the month instead of on the second Saturday. New Members admitted since the last Monthly Meeting of the Society :—W. C. Rownsley, and Charles Gregory Feinagle, Esqs. Dr. Mueller’s paper,—‘ Definitions of rare and hitherto unde- scribed Australian Plants,’ was laid before the Meeting. Clement Hodgkinson, Hsq., read a paper on—* Engineering Earthworks, and Railway Cuttings,” illustrated by tables and dia- grams. Dr. Eades having vacated the Chair, which was occupied by Dr. Iffla, brought forward an essay—“ On the comparative Actions of Disinfecting Agents.” Dr. Eades showed that hypochlorite of lime should be considered as the true disinfecting agent. By the combination of the carbonic acid of the air with the base of this salt, hyponitrous acid (Cl +0) was eliminated. The elements of this acid being nearly equally negative electric repel each other, thus oxygen is set free, purifying the air, while the disengaged chlorine acting on aqueous vapour, an additional quantity of oxygen is set free, at the same time that other atoms of chlorine decompose the fcetid gases. After some further remarks on the part of Dr. Eades, some discussion took place, and Charles Feinagle, Esq., observed that upon the theory now proposed, the moisture of the air would be rapidly exhausted by decomposition, in which case the chlorine would cease to act. To this it was replied that the chlorine was given off in its moist state. . Several of the Members expressed their opinions in reference to Dr. Eades’ assertions, and the subject was then allowed to give place to the other business of the Meeting. The President having arrived, Dr. S. Iffla vacated the Chair, and requested the President to occupy the same. The progress made with reference to the contemplated exploring expedition having deen brought forward before the Meeting by the President, it was noved by Richard Eades, Esq., M.D., seconded by R. Brough ‘myth, Esq.,and carried—‘ That the Council be instructed to pre- vi Proceedings. pare petitions to his Excellency the Lieutenant Governor and to the Honorable the Legislative Council, requesting them to assist in carrying out the object aimed at.” S. Iffla, Esq., M.D., brought before the Meeting the advisability of an application for a Royal Charter, in reference to which it was moved by J. H. Brooke, Esq., seconded by Dr. Iffla, and car- ried—* That the Council be instructed to make the necessary ar- rangements to prepare the form of application for the incorporation of the Society by a royal charter, and their report be laid before a General Meeting of Members as soon as possible.” December 12th, 1854. Montuty Meeting. D. E. Wilkie, Esq., M.D., in the Chair. The Minutes of the last Meeting were confirmed. New Members admitted since the last Meeting :—Major Norman Campbell, the Right Rev. Dr. Goold, Roman Catholic Bishop of Melbourne, Sir William a’ Beckett, Chief Justice, the Right Rev. Dr. Perry, Lord Bishop of Melbourne, the Very Rev. Dr. Fitzpatrick, Dr. McKenna, W. H. Campbell, T. Pardoe, and S. Hanaford, Esqs. The following memorials in compliance with the resolution of the last Meeting were unanimously agreed upon. To His Excellency Sir Charles Hotham, Knight, Commander of the Bath Lieutenant Governor of Victoria, ée. * The memorial of the Members of the Philosophical Society of Vic- toria in General Meeting assembled, Humbly sheweth :— That your Memorialists, deeply impressed with the necessity of elicit- ing the fullest information relative to the available sources of industry, which exist in the Colony, would beg to draw the attention of your Excellency to the following suggestive scheme, which, in the judgment of your Memorialists, is adequate to the end proposed. That your Memorialists having seen with regref the inutility of indi- vidual exertions in prosecuting researches for auriferous fields, coal and. other minerals, have devised and proposed that duly qualified agents should be sent to explore such parts of the Colony as are most likely to possess mineral or metallic wealth; and that these agents, on the com- pletion of such examinations, should report to your petitioners of the same for the information of themselves and the public. That these agents should also collect specimens which might seem to them of prac- tical value or of peculiar scientific interest. : That your Memorialists have brought this matter before the inhabi- tants of Victoria, and have sought to induce their co-operation, but Proceedings. vil without practical effect ; and as the resources of the Philosophical So- ciety are insufficient for the prosecution of these researches, your Memo- rialists are therefore led to beg Your Excellency’s consideration of the great and incalculable benefits that might result from such inquiries, pursued under the supervision of your Memorialists; and if it should appear of similar importance to Your Excellency, your Memorialsts would earnestly pray for such support as your Excellency may deem - advisable to extend, And your Memorialists will ever pray, &c. To the Honourable the Legislative Council of the Colony of Victoria The Memorial of the Members of the Philosophical Society of Victoria in General Meeting assembled, Humbly sheweth :— That your Memorialists, mindful of the onerous duties which devolve upon them as citizens, and as Members of a Scientific Institution, have endeavoured to enlist the support of the inhabitants of Victoria in the prosecution of inquiries, tending to the discovery of the various natural productions which are held to be the chief sources of wealth in all countries. That your Memorialists have proposed to establish, on a broad basis, a system of discovery replete with benefits to the Colony at large, and of high and significant importance to the scientific world. Your Memorialists propose to send to the interior, or to such districts as they shall determine, suitably-qualified persons to examine and report upon the mineral as well as other natural resources of such districts, and to collect specimens in natural history of a practical value, so that the wealth of this country in these departments may become available to the inhabitants. Your Memorialists have not received as yet that support from the public which would warrant them to attempt the realisation of this scheme; and therefore your Memorialists would respectfully draw the attention of your Honourable House to the consideration of this matter, relating as it does to the immediate prosperity of the country. That your Petitioners feeling the responsibility which attaches to a work of the magnitude here indicated, would beg the support of your Honourable House in the furtherance of the object aimed at. And your Petitioners will ever pray, &c. J. H. Brooke, Esq. moved, and S. Wekey, Esq. seconded; and it was agreed,— That the memorial to His Excellency the Lieutenant Governor be presented by a deputation consisting of Captain Clarke, R.E., Dr. Hutchinson, and Dr. Iffla. Dr. E. Davey read an essay “On the construction of an instrument for ascertaining the mean temperature of any place.” Vili Proceedings. Ludwig Becker, Esq., read a paper “On Meteorological Observa- tions at Bendigo.” Presents acknowledged,—Collection of Crystals of Gypsums from the Salt Water River—Edward Wilson, Esq. January Ith, 1855. Montuty Merrtine. The President in the Chair. The minutes of the last Meeting were read and confirmed. The Honorary Secretary informed the Meeting that in compli- ance with the resolution agreed to at the last General Meeting, respecting the application to His Excellency the Lieutenant-Go- vernor, for a grant, for the purpose of carrying out the scheme of an Exploring Expedition contemplated by the Society, the following correspondence has taken place between His Excellency the Lieu- tenarit-Governor and one of the Honorary Secretaries :— Museum of Natural History, Melbourne, December 14th, 1854. Sir,—I have the honour to enclose the copy of a memorial of the Members of the Philosophical Society of Victoria to His Excellency the Lieutenant-Governor, and request you will be pleased to ascertain when it will be convenient to His Excellency to meet the deputation, consisting of the Surveyor-General, Dr. Hutchinson, and Dr. Iffla, appointed to present the said memorial. I have the honour to remain, Sir, Your most obedient Servant, S. Wexry, Hon, Sec. Captain J. H. Kay, R.N., Private Secretary. To the above letter the following reply was received :— Government Offices, Melbourne, 18th December, 1854. Sir,—I am directed by the Lieutenant-Governor to acknowledge the receipt of your letter of the 14th inst.; and in replying to it His Excel- lency trusts that the Philosophical Society of Victoria will not think him inattentive to their wishes, if he conveys his views to them in writing. The Lieutenant-Governor regrets that the insufficiency of the public funds to meet the public requirements renders it imperative upon him to stay every possible expense ; but that with regard to gold, the nume- rous prospecting parties (which are searching the length and breadth of Proceedings. ix the land), in the Lieutenant-Governor’s opinion, fully encompasses the end sought by the Society; whilst with regard to coal, it is reported that the fields at Western Port are sufficient to last a generation. At a future time the Lieutenant-Governor will be most happy to lend his aid in furthering the important objects which the Philosophical So- ciety of Victoria has in view. I have the honour to be, Sir, Your most obedient Servant, 8. Wekey, Esq. J. H. Kay, Private Sec. Some of the members did not seem to understand the proper mean- ing of the letter of the Private Secretary, as the latter part of the said letter appeared to be contradictory of its former part. In the first part of the letter it is stated, “that as the length and breadth of the land is searched by prospecting parties, and as it is reported the coal-fields at Western Port are sufficient to last a generation,” therefore, in the Lieutenant-Governor’s opinion, this circumstance fully encompasses the end sought by the Society, which is as much as to say that the objects of the Philosophical Society are unneces- sary,—whereas in the concluding sentence of the letter it is stated, that “at a future time the Lieutenant-Governor will be most happy to lend his aid in furthering the important objects which the Philo- sophical Society of Victoria has in view.” The subject however dropped. It was announced by the Honorary Secretary that a proposal had been received from the Victorian Institute, to amalgamate with the Philosophical Society; but as yet nothing definite has been done. On the subject of the amalgamation a discussion arose, when it was moved by Dr. Iffla, seconded by Mr. S. Wekey, and carried:— “That as soon as the correspondence between the Victorian Insti- tute and the Philosophical Society is complete respecting the pro- posal of the amalgamation of the two societies, a Special General Meeting be called to consider the matter.” D. E. Wilkie, Esq., M.D., read a paper “ On the probable Failure of the Yan Yean Reservoir.” After an ananimated discussion as to whether the paper be pub- lished or not, on the motion of Dr. Iffla, seconded by Dr. Eades, it was resolved :— “That a commission, consisting of F. C. Christy, Esq., Frederick Acheson, Esq., and Clement Hodgkinson, Esq., Engineers, and §. Wekey, Esq., Secretary, be appointed to enquire into the statements set forth by Dr. Wilkie, respecting the Yan Yean Reservoir, and to report to the Society at the General Meeting.” Balfour Stewart, Esq., then read a paper “On the Influence of Gravity on the Physical Condition of the Moon’s Surface.” And also a second essay “On the Adaptation ofthe Eye to the Nature of the Rays which emanate from Bodies.” c x Proceedings. February 20th, 1855. Montuty MeEeEtina. The President of the Society having been detained, Mr. Justice Barry was invited to take the chair. The reading of the minutes of the last meeting was postponed to the next meeting. The following Gentlemen were announced to have been admitted members of the Society, since the last meeting :— The Honourable the Attorney-General, W. F. Stawell, Hsq.; Captain Pasley, R. E., Colonial Engineer; Wm. M’Crea, Esq., Colonial Surgeon; W. H. Archer, Esq., A. Registrar-General. The Honorary Secretary, informed the meeting that, in compliance with the resolution of the last meeting, the com- mission appointed to investigate the statements set forth in a paper read by Dr. Wilkie, on the Yan Yean Reservoir, went up to that district and examined the reservoir, as well as the Plenty River and its sources. They made measurements of the Plenty at various parts, with the view of ascertaining the average quantity of water the river is capable of discharging. ‘They likewise made measurements of the main tributaries, viz., the western and eastern arms, and traced the source of the latter to the top of Mount Disappointment. The report of the commission, however, as it involved a vast amount of calculation, as well as actual experiments upon the evaporation, could not be laid before this meeting with all the necessary details. He stated further that the commissioners had furnished Dr. Wilkie with the result of their. measurements founded on which data his present paper was enlarged and amended_ Dr. Wilkie then read a paper on the Yan Yean Reservoir, founded on the data above referred to. He endeavoured to show that there would not be sufficient water in the reservoir, after deducting the evaporation, to supply more than 75,000 individuals at forty gallons per head per diem; and he argued that on the constant-service principle, the supply might be found altogether insufficient even for that number; he stated that it had been found by the ex- perience of other cities that forty gallons could not be depended on as a sufficient supply. He showed that from fifty to 100 gallons per head per day were frequently used, and that several cities in England have been obliged to abandon the constant-service principle altogether from an insufficient supply of water. Dr. Wilkie also strongly objected to the principle of storing water in a swamp, and thought that it would become very much deteriorated and incurably infected with animalcule and vegetable productions which no filtration could remove. He entered at ereat length into Proceedings. xi the question of the probable amount of the water-shed of the Plenty, which he estimated, according to Dr. Thomson’s method, at one- ninth (1-9) part of the rain ; and showed that the evaporation in this country was so enormous that if the whole water-shed of the Plenty could be secured for the reservoir it would be nearly all evaporated in twelve months. After the reading of the paper the Chairman called on the members to offer their remarks upon its contents. Mr. Acheson stated on the part of the committee the result of their calculations. Mr.Christy observed that about the same quantity of water reached the river here as in England. Dr. Wilkie said he was exceedingly sorry that the members of the commission had not brought up their report- He was also much surprised to find that, instead of availing themselves of the actual measurements, and from them deducing the supply for the reservoir, they had merely given some theoretical views with respect to the probable amount, and which were founded upon the deduc- tions of Mr. Dempsey, whose name he had never heard. The late Mr. Blackburn had, in his evidence before theSelect Committee, given 5,000 gallons per minute as the average discharge of both branches of the river above the swamps, and he, Dr. Wilkie, had founded all his calculations upon that estimate, although, before the river reaches Yan Yean, one half was lost by evaporation in the swamps. He had, however, allowed an increase of one-third in the volume of the river for the six winter months, independent of floods; and now argued that, as the climate of Australia was exceedingly dry, and there were very few rivers, and those had but a small quantity of water in them, a much less proportion of rain reached the rivers here than in England. It was utterly impossible, he considered, that out of an inch of rain three-fourths could reach the river from every part of the drainage area; but his opinion was, that from the geological formation of the Plenty Ranges, a very large proportion of the rain was absorbed, and that it was because the ranges retained the winter rain and gave it out during the summer, that the stream was permanent. Dr. Iffla directed the attention of the meeting to the importance of the purity of water to the health of the inhabitants; for when filled with a great quantity of vegetable matter it was likely to be contaminated by a large quantity of animalcule. This was the more likely to take place in a reservoir, where the water could not freely flow, and where it was constantly under the action of the solar rays. The President of the Society who in the mean time arrived, said that the thanks of the public were due to Dr. Wilkie, for having directed public attention to this most important subject in a paper written with so much care. The meeting could not come to any Xil Proceedings. decision until the report of the commission had been laid before the members; and he thought that the present paper should not be published without the report. He hoped that the gentlemen ap- pointed on the committee would furnish to the society such complete and detailed information as would be likely to settle the subject. The Honorary Secretary, stated that Mr. Hodgkinson one of the members of the committee, having met with an accident, was unable to act, and asked whether it would not be necessary to appoint another in his stead. The President said that the committee, as he understood, having already completed the measurements and agreed upon the data, they could finish their report, and it would not be necessary to put a new member upon the committee. The Chairman then asked the members whether Dr. Davey’s paper “On the Meteorology of Melbourne” should be read that evening. It was, however, owing to the late hour, determined, that the reading of the paper should be postponed till the next meeting, and then to be considered in priority to any other business. Thanks were then voted to the Chairman, and the meeting separated. March 13th, 1855. Montaty Merrrine. ‘The President in the chair. The minutes of the last two meetings were read and confirmed. New members, elected since last meeting, were introduced, viz., Alexander Kennedy Smith, Arthur Dobree and F. Phillips, Esqs. According to the resolution of the last meeting, Dr. Davey’s paper “On the Meteorology of Melbourne” was read first. The Honorary Secretary, on laying before the meeting the report of the Committee, appointed to investigate the Yan Yean water scheme, announced that he considered it his duty to mention that he had reason to ask at the last meeting whether instead of Mr. Hodgkinson being obliged to retire from the Committee, it would be necessary to appoint another ? He stated as his reasons, that the remaining members of the Committee did not agree upon various important points contained in the report, andin his opinion it was desirable that the statements set forth by the Committee, upon such an important question as the water’ scheme, should have been considered by a larger number of members than the present Committee consisted of. For reasons above stated, he did not feel justified in signing the document now being submitted to the meeting, and he believed that had his request at the last Proceedings. xlil meeting been complied with, the doubts entertained by the public on the Yan Yean water scheme would have been more likely removed he believed than will be by the present report. The report of the Committee appointed at a meeting held on the 9th of January last, to investigate the Yan Yean water scheme, was read, and the statements illustrated by diagrams, shewing the physical character of the country in the neighbourhood of Yan Yean, with the tributaries and sources of the River Plenty and various measurements. Clement Hodgkinson, Esq., read a paper, ‘‘On the Cause of the enormous difference between the Ratio of availabie Rainfall in the Plenty District as adopted by Dr. Wilkie and that approved by the Commission.” Dr. Wilkie then read his additional observations on the state- ments of the committee, contained in the reports. He enlarged upon the committee having taken as an authority the estimate of available rainfall of Mr. Dempsey, which is quite inapplicable to this case. Mr. Acheson, on behalf of the committee, stated that the com- mittee was not guided by the calculations of Mr. Dempsey ; but, that having arrived to the same result with the above named author, this fact corroborated that the committee was correct in this calcu- lation.« Letters received from the Victorian Institute, having reference to the proposal of the Institution to be amalgamated with the Philosophical Society, were referred to the consideration of the council. The Hon. Secretary announced, that at the last meeting of the council of the Society, it was proposed to petition the Hon. the Legislative Council, requesting that hon. house, in case the Government should not continue to maintain the Museum of Natural History, to place it under the custody of the Philosophical Society, and the society will try to do all they can to keep up that only national institute existing. The President, in reference to the proposal of the Council, stated, that the Legislative Council, having taken the matter under con- sideration, this proposal should be deferred until the final decision of the House with reference to the maintenance of the Museum of Natural History should be known. March 27, 1855. Sprctat Generat Mesztine. A. K. Smith, Esq., in the Chair, The minutes of the last meeting were read and confirmed. The Chairman, after having stated that the meeting was convened in compliance with the resolution passed at a monthly meeting of XIV Proceedings. the society, held on the 9th of January last, when it was resolved that the correspondence with reference to the amalgamation of the Victorian Institute with the Philosophical Society, when complete, be laid before a special general meeting for their consideration, called on the Secretary to read the correspondence referred to. After the correspondence had been read, Mr. S. Wekey, the Hon. Secretary, laid before the meeting the statements having reference to the comparative relation of the two societies. He said, that according to the report of the Victorian Institute read before a half-yearly meeting held on Thursday, 8th March, 1855, it was stated that the Victorian Institute had a balance in hand of £68 9s. 8d, ; while the Philosophical Society at the same time had available funds from members’ subscriptions to the amount of £170, which, in case of an amalgamation, will leave, in favour of the Victorian Institute, £100. At a meeting of the Victorian Institute, held on the 8th of March it was reported, that up to that date six papers had been read, while on the other hand, the Philosophical Society, during the same period of time, had received seventeen papers, which, in case of an amalgamation, would leave in their favour eleven papers. As to the officers of the Victorian Institute, an amalgamation de facto has already taken place, since the President of the Insti- tute, with several members of the council, are now actually mem- bers of the Philosophical Society; and, although this society had no opportunity as yet to open a wider field, for the exertions and attainments of those who, previously members of the Victorian Institute have afterwards jomed the Philosophical Society, as far as he can judge, the members of the Society are anxiously waiting for the first opportunity, at the next anniversary meeting, to be held in August, to invite the co-operation of some of them to occupy such a post in the society as will give them an opportunity of exerting themselves in behalf of the interests of the society, as well as the advancement of science in Victoria. As to the annual subscription, there is some difference between the Victorian Institute and the Philosophical Society. The entrance fee and the subscription to the Philosophical Society is considered by some high; but although in one instance its reduction was con- templated, the council did not deem it expedient to reduce the same. A discussion on the subject then took place, and on account of the small attendance the meeting was adjourned, and the subject referred to the next monthly meeting of the society. Proceedings. XV April 10th, 1855. Montuty Meerrine. Dr. Wilkie in the Chair. The minutes of the last meeting were confirmed. R. Brough Smyth, Esq., read a paper “On the Influence of the Physical Character of a Country on the Climatology.” He endeavoured to show how far the physical character and geological formation of a country react upon the climatology, and how the course of rivers and creeks are influenced byit. He next showed, by diagrams and sections, the principal geological features of Victoria, and compared the formation of the ranges as influen- cing the course of the main streams of the rivers running parallel with them, and mentioned the following rivers as examples :—The La Trobe, the Goulburn, the Snowy River, and the Yarra. He next showed that little reliance could be placed on meteoro- logical observations, made at a certain place, either with regard to the quantity of rain or the evaporation, as the greater portion of Victoria consisted of alternate ranges and plains. After referring to the origin of springs and their effects, in this climate, he concluded with practical applications on the formation of reservoirs, pointing out the absolute necessity of a due recog- nition of scientific principles in opposition to empirical knowledge in all such undertakings. William Blandowski, Esq., laid before the meeting specimens of rocks, containing fossil remains, forwarded by F. Acheson, Esq., through him. The peculiarity of these rocks were, that they were discovered in the vicinity of one of the first gold-fields of Victoria, though the fossil remains were those of oceanic animals usually found at a great depth below the surface; these were discovered between layers of hard blue slate, in a vein about fifteen inches thick. On the subject of: the amalgamation of the Philosophical Society and the Victorian Institute, the Chairman stated that at a special general meeting held a fortnight ago, the subject was adjourned to this meeting, on account of the small attendance; and he now begged to suggest that the subject be referred to the council of the society, and that they should report to a general meeting their opinion as to the best course of proceeding. Dr. Iffla agreed with the views of the Chairman. Mr. Blandowski thought it better to discuss the subject at once- When it was moved by R. Brough Smyth, Esq., Hon. Sec., and seconded by Wm. Blandowski, Esq. and carried. “That six- XVi Proceedings. members of the Philosophical Society should meet a committee of six of the members of the Victorian Institute, to arrange matters on the subject of the amalgamation of the two societies, such committee to consist of Drs. Wilkie, Iffla, and Eades, and Messrs. Blandowski, Wekey, and the mover.” Presents acknowledged.—Specimens of the clay slate formation with fossil remains, F. Acheson, Esq. ; specimens of basalt and fine crystals of carbonate of lime, R. B. Smyth, Esq. May 18th, 1855. Montruuiuy MERFTING. In the absence of the President, S. Iffla, Esq., M.D., was voted _ to the chair. The minutes of last meeting were read and confirmed. The Honorary Secretary announced the names of the following new members, elected since the last monthly meeting of the so- ciety :—Hugh Culling E. Childers, Esq., Ralph Lowe, Esq., William Thomson, Esq., and Professors McCoy and Wilson, of the Melbourne University. Clement Hodgkinson, Esq., read a paper entitled ‘“ Practical Hints on the best Method of Guaging Rivers accurately,” with a brief description of a modification of the hydrometrical pendulum, adopted by the writer, with an original table. W. Blandowski, Esq., read a paper, “ On the Primary Upheaval of the Land around Melbourne,” illustrated by a large number of specimens from that locality. D. E. Wilkie, Esq., M.D., read a paper, “On the Data on which we have to depend for our Water Supply.” The Honorary Secretary read the following report of the com- mittee appointed to consider the propriety of the proposed amalgamation with the Victorian Institute. Report. The members of the Philosophical Society and of the Victorian Institute, appointed to confer upon terms of amalgamation of the two bodies have the honour to report to their respective societies as follows :— They have held four meetings, have considered the fundamental principles and present position of the two societies, and find no impedi- ment to amalgamation. They accordingly recommend— That the two societies be amalgamated, under the title, pending the grant of a royal charter, of ‘‘ The Philosophical Institute of Victoria.” That the following gentlemen be office-bearers of the Philosophical Proceedings. XvVil Institute of Victoria :—President, Captain Clarke, R.E.; vice-presidents, his Honor Mr. Justice Barry aud Godfrey Howitt, Esq., M.D.; council, the present members of the council of the Philosophical Society and of the Victorian Institute ; treasurer, D. E. Wilkie, Isq., M.D.; honorary secretaries, S. Wekey, Esq., R. B. Smyth, Esq., W. 8. Gibbons, Esq, That the members of the Philosophical Institute of Victoria shall consist of fellows, resident and honorary members. That fellows shall be elected from among the resident members by ballot, at the monthly meetings of the society; the proportion of votes for deciding the election of fellows to be at least four-fifths of the members voting. That peident members be admitted on application to, and approval by the council. That honorary membership shall be considered one of the highest marks of distinction the society can confer. That the objects of the Philosophical Institute shall be as stated in the prospectus of the Philosophical Society, viz. :—The objects of the society shall embrace the whole field of science, with a special reference to the cultivation of those departments that are calculated to develope the natural resources of the country. That the mode of operation stated in the prospectus of the Philo- sophical Society be adopted, with some addition, viz. :—The objects of the society will be carried out by original researches conducted by the members, and by original papers, to be read-at the periodical meetings, and published under the direction of the society; and by such other means as may be deemed expedient. That the principle set forth in the paragraph headed ‘“ Bye laws and Regulations,” in the prospectus of the Philosophical Society, viz. :— ‘« The society shall be definitely established on the principle of the Royal Society of London, as far as the existing bye-laws and regulations of that Society may be applicable to the present local circumstances of Victoria,”—be rejected, inasmuch as the regulations of the Royal Society of London forbid the discussion of papers read at general meetings,— such discussion being deemed desirable, and forming an essential part of the scheme of the Victorian Institute. That bye-laws and regulations be therefore framed hereafter by the Philosophical Institute. That with regard to the property of the society, the specimens of natural history contributed to the society shall be considered the property of the National Museum until otherwise ordered and resolved by the annual general meeting of the society. That the resolution of the annual general meeting, shall not ex- tend to those specimens that are found in actual possession of the society at the time of such resolution being brought in, such specimens being already the property of the National Museum; but merely to such specimens as may be collected after the date of the said resolution being made. That every paper, plan, model, &c., presented to the society shall be considered the property thereof, unless there shall have been made some previous arrangements with the donor; and the council may publish such paper, and a description of such plan or model, any time they think proper. j No member shall publish on his own account, or give his consent for publication of, any written communication read to the society, without the previous consent of the council. XVill Proceedings. These recommendations are based on the four paragraphs headed ‘‘The Property of the Society,” in the prospectus of the Philosophical Society. Some alterations, however, it will be seen have been made, because it was not deemed desirable that models and books presented to the society should pass out of their hands, because the first of these paragraphs, literally interpreted, would deprive the society of all property whatsoever, even in their own transactions, and because such interpretation contradicts the third paragraph, which has been adopted verbatim. That the subscriptions at present payable by the members of the Philosophical Society and of the Victorian Institute respectively, be considered the subscriptions due to the Philosophical Society of Victoria for the current year, after which the subscription to the Philosophical Institute can be fixed by that body. In recommending that the Victorian Institute and Philosophical Society be amalgamated on the above general terms, the fact has been borne in mind that, after amalgamation, these terms would be subject to complete revision by the Philosophical Institute, and that all details can be most properly adjusted by general vote of the united body. In con- clusion, therefore, the members of the conference appointed to consider the terms of the proposed amalgamation, strongly recommend that to bring about that desirable end, minor objections should be waived and concessions freely made on both sides, as such concessions will merely be required to permit the preliminary difficulties to be overcome, and will not be permanent unless hereafter approved by the members of the Philosophical Institute of Victoria. FRED. SINNETT, CHarrman. The following presents were acknowledged :— A large number of specimens with numerous fossil remains, from the Anderson’s Creek Gold Diggings, collected by Messrs. Blan- dowski, Acheson, and Wekey. These specimens are of great scientific interest as they may be considered to furnish data for determining the geological age of our earliest gold field. Fifty specimens of different species of Mollusca, collected at Sealer’s Cove, and forwarded by Dr. F. Mueller, for the Museum Dr. Mueller likewise exhibited a very singular specimen of phospho- rescent plant, the luminous agaricus. The plant although now dead, on being moistened exhibited considerable luminosity. June 12th, 1855. Montuty Mzerrine. Clement Hodgkinson, Esq., in the Chair. The minutes of the last Meeting were read and confirmed. Dr. F. Mueller read a paper :—“ Definitions of hitherto unde- scribed Plants from the Australian Alps,” illustrated by carefully: arranged specimens. R. Brough Smyth, Esq., Hon. Sec., laid before the Meeting a Proceedings. X1x Meteorological Table for the months of April and May, informing the Meeting that such Meteorological Table will be laid before the Society at each monthly meeting. Clement Hodgkinson, Esq., requested the secretary to read his observations ‘‘ On the statements of Dr. D. E. Wilkie and Charles Griffith, Esq., concerning himself, with reference to the Yan Yean ea Scheme, pointing out the several errors into which they had allen.” July 10th, 1855. Montuty Mertine. Dr. J. Maund in the chair. This was the first general meeting of the members of the Philo- sophical Society and the Victorian Institute, since the preliminary arrangements, to effect the amalgamation of both societies, under the name of the Philosophical Institute of Victoria, were com- pleted. The papers read at this meeting having been written by members of the Philosophical Society, with the view of being laid before the meeting of the Philosophical Society; in order to com- plete the Transactions for the past year, these papers as well as the proceedings of the meeting are given in this volume. Dr. Eades, in proposing that Dr. Maund should take the chair, remarked that as this was the first meeting of the united societies, and as the newly-formed society, under the title of the Philoso- phical Institute, met in the room where the late Philosophical So- ciety held their meetings, he felt it, as a matter of delicacy and courtesy, that, in the absence of the President, one of the members of the late Victorian Institute should take the chair. Accordingly he felt happy in proposing Dr. Maund. The Chairman, in opening the meeting, remarked that it was the first meeting of the body, composed of the members of the late Philosophical Society and of the Victorian Institute. He trusted that the members of the Philosophical Institute would co- operate for the attainment of the objects contemplated by the so- ciety. The Honorary Secretary, announced the admission of new members since the last meeting of the Philosophical Society, viz. :—A. B. Johnson, Esq., Robert Sloane, Esq., resident members: and Robert Scott, Esq., corresponding member of the society. A report On the physical character of the county of Heytesbury, to the Surveyor-General, Captain Clarke, R.E., by the Resident Surveyor, Robert Scott, Esq., was read by Fred. Acheson, Esq; CE. This paper embodied the observations of the author during a professional tour through the country drained by Gellibrand’s Xx Proceedings. River and Curdie’s Creek. For the better illustration of the au- thor’s journey, a map of the county of Heytesbury was exhibited, showing the main geographical features as far as they have been laid down on the maps issued by the general survey. The author commenced by a detailed description of Lake Elingamite, which is supposed to be the source of Brucknell’s Creek. This lake is about four miles in circumference, and is situate six miles and a half south- west frorn the parish of Colongulac. He started from thence fon foot, surveying the whole course of Curdie’s Creek and its numerous tributaries. He describes the soil in that neighbourhood as poor in quality, but well grassed and heavily timbered with stringy bark, and other species of Hucalypti. Many of the valleys are of a richer description, well clad with lightwood, gum, &c. The formation generally appears to be basaltic or volcanic. The “Stony Rises,” on the east side of Lake Purrumbeet are described as irregularly piled masses of trappean rocks. Numerous marshes and swamps, in this tract of country, supply Curdie’s Creck, and the soil is of a light chocolate colour, supporting various species of the eucalyptus and the accacia. Some of the higher lands, bordering on Curdie’s Creek, present the remarkable fact of the existence of marine shells, intermixed with fragments of limestone quartz, &. The land southward of this is of an undulating character, and it is in some parts covered with thick scrub and strong grass, from whence has arisen a considerable surface deposit of decomposed vegetable mat- ter, which the author seems to think might be used as peat. After supplying much useful information respecting the inland district of Heytesbury, the author describes his journey southwards to the coast, and notices the different kinds of rocks, which form the cliffs, near the mouth of Gellibrand’s river. The strata, it appears, is nearly horizontal, and, from the author’s allusions to its calcareous nature, and the presence of calcareous concretions, it may be pre- sumed that it does not differ, in any remarkable degree, from the tertiary formations in other parts of the coast. The author’s sub- sequent remarks on the navigation of the streams, near this part of the coast, were of a practical character, and could not be properly entered into without explanatory charts. The Chairman observed that the conference of councils had di- vided on the advisability of admitting discussion on each paper.— The late Philosophical Society had followed the practice of the Royal Society of England, which forbids discussion. It was, how- ever, deemed advisable that free discussion should be admitted on every subject that was introduced, so that every possible light might be thrown upon it; he therefore invited the members to offer any remarks they may have with reference to the statements contained in the paper. Mr. Acheson adverted to the great importance of the discovery of peat mentioned as existing in the locality described. He ques- Proceedings. XX1 tioned, however, whether it was not mistaken for decayed vegetable matter, which often resembles peat, but is quite distinct from it. Mr. Hodgkinson alluded to the discovery of the chalk formation by the writer, he was, however, of opinion that the geological for- mation of the district would not bear out the existence of chalk in those localities. The chairman stated that chalk and other salts, when held in solution, were frequently deposited on evaporation ; and that rich crops of natural crystals were frequently found in caverns. Some- thing of this kind was mentioned in the paper. Mr. Blandowski believed that the writer did not furnish sufficient evidence in proof of his statements concerning the chalk formation Dr. Maund suggested that the difference of view might arise from the change by natural causes of limestone, the oxide of cal- cium, into chalk, the carbonate of lime. The lime might have been held in solution as a bicarbonate, and the other equivalent of carbonic acid have been taken up from the air. Mr. Blandowski disagreed with the views of Dr. Maund, andsaid that although the chemical composition of lime and chalk is similar, the term chalk could not be applied to all decomposed limestone, and they were different in a geological point of view. Clement Hodgkinson, Esq., read a paper “On the favourable geo- logical and chemical nature on the principal rocks and soils of Vic- toria, in reference to the production of ordinary cereals and wine.” Mr. Hodgkinson, after making some general allusions to the geolo- gical configuration and soils of the other Australian colonies, arrived at the conclusion that soil in general derived from volcanic rocks in Australia was more fertile than that derived from aqueous or plu- tonic rocks. ‘The writer gave an analysis of soil derived from dis- integrated basalt near Melbourne. He ‘referred to the important fact, that, near Sydney, there was some land on trap dykes which was under culture and cropped during the past half century, with- out manuring or fallowing, while its fertility remained undiminished. Mr. Hodgkinson attributed this to the intensity of the disintegrat- ing action that has been maintained in the soil, and which action, in his opinion, had set free during the period that the land had been cultivated as large a quantity,of alkalies, phosphates, &c., as had been consumed by the crops. He maintained that soil of this favourable quality occurs in large numbers of isolated patches omong the vol- canic rocks of Victoria. Mr. Hodgkinson next explained the im- portant influence of the inorganic constituents of the soil of the vineyard on the quality of its wine. He demonstrated that the dis- integration of clayslate was exceedingly favourable for the production of superior wine. He referred to the large quantity of land of this description in the basin of the Yarra, at an easy distance from Mel- bourne, which he stated to be analogous to that of the celebrated vineyards on the schistoze mountains of the Valley of the Rhine. XxXil Proceedings. In reference to the paper of Mr. Hodgkinson, a letter was read from R. B. Smyth, Esq., one of the hon. secretaries, who was unable to attend. Melbourne, July 9th, 1855. Drar Srr—I have to thank you for having permitted me to peruse a manuscript of yours on the soils, and general agricultural properties of the lands in Victoria. You have handled the subject so carefully, and displayed such a large amount of practical knowledge in that department of science, that I dare not venture to offer a criticism. Your analysis of the volcanic soils is borne out by the facts elicited by Klaproth, Vauquelin, Rose, and others, in reference to the minerals which these rocks contain; and you have done great service to agricul- ture by pointing out the causes of the remarkable fertility of soils of such a character. Let me offer a few remarks, in addition to what you have stated in your paper, in elucidation of the facts there put forth. One great cause of the fertility of volcanic soils is due to the colour, consistency, and the consequent comparative rapidity with which such soils radiate heat absorbed during the day. Experiment has shown that the general temperature of rich black mould is some degrees higher than wet clay during the solar heat; and a regular scale of temperatures is found between white clay saturated with moisture and black earth. Now, in addition to this, it is found that a rich black soil, radiating heat as it does with such rapidity, necessarily condenses a larger amount of dew than a clay soil, thus supply the plant with an absolute necessary in com- parative abundance. This property is really an objection in a climate such as England, if in excess; but in this climate it must be held asa prime consideration in choosing land for agricultural purposes. I do not hold that this applies in strictness, or with equal force, to all voleanic soils. It is, however, the characteristic of the volcanic soils in this country. For the growth of cereals—wheat for instance—where the roots are fine and radiating, and the stalk high and heavy, possibly volcanic soil of the richest kind is not to be chosen. Itis perhaps better adapted to horticultural products. Another cause of the fertility of this soil is to be found in the vast amount of decaying and decayed vegetable matter which it contains.— This, I need not remind you, has the property of absorbing carbonic acid from the atmosphere, and in itself, almost indestructible, is a never- failing storehouse for this essential ingredient in vegetable substance.— When engaged in experimenting in England, in 1850 and 1851, I re- peatedly raised crops from pounded charcoal. The plants were kept in pots, regularly watered, and subjected to different temperatures, and the results were most satisfactory. I may venture to say that almost any - soil may be rendered productive by the addition of pounded charcoal, or coal dust, or soot. It is the vulgar opinion of agriculturists that charcoal in this shape is really appropriated by the plant, but this is now utterly exploded where- ever experiment has taken the place of vague conjecture. Having devoted a considerable portion of my leisure time in England, some three or four years ago, to the consideration of these questions, Proceedings. XXii1 perhaps I may be competent to expréss an opinion as to the justness of your general conclusions. The subject is so important, that I venture to suggest that you should extend your experiments, with a view to com- pare the different soils in this country from distinct geological formations ; possibly the information so gained might be viewed with distrust by the agriculturists in Victoria, and tardily brought to bear upon their practice, but my experience has shown that agriculturists readily accept anything simple, suited to their limited views of these matter; and whenaided by the really able and learned agriculturists in England, (where there are now many}) working on scientific principles, the less informed grasp at the empirical results, and thus great good is the consequence, though perhaps in an objectionable form. Whoever assists in imparting a knowledge of the resources of our beau- tiful and highly-favoured country—second to none on the face of the earth—will find in pleasing reflections, perhaps, his only reward—not small—not to be despised—a reward sufficient for him who can find de- light in the toil of discovery; and he will be laying the foundation for our future national greatness. am, With every sentiment of respect, Your most faithful servant, R. Broues Smyru, Mining Engineer. Mr. Wekey stated that he could not exactly agree with Mr. Smyth’s views that the colour contributes to the fertility of the soil, although he admitted that it is an important medium in promoting germination. He proceeded to say that every one who has made the common experiment of transmitting the solar rays through a prismatic spectrum, will have observed the variety of colours that by such means are thrown on a piece of white paper or other mate- rial. Among the colours thus distinguished, one observes the vio- let, indigo blue, yellow, red, &e. Of these, the blue, or chemical ray, called also the actinic ray, which is of much importance in ex- citing germination, and any medium, may it be the colour of the soil or of dark blue glass, &c., through which most of the blue rays can be transmitted and conveyed to the seed will materially contri- bute to prompt germination. Consequently, from seed sown in a black soil it is likely that a greater per centage will germinate than from light coloured soils. Mr. Wekey did not think that the colour of the soil would be of importance in forwarding the growth of the plant after it was above ground, when all action of the chemical ray ceases. He continued, stating that after the plant is above ground, the yellow or luminous ray conduces to develop the woody fibres, so as to prepare it ultimately for the action of the red or heating rays which ripen and develope the saccharine matter in the fruit. Mr. Wekey agreed with Mr. Hodgkinson so far that the disintegration of rocks forms the best soil for the vine, as it furnishes an additional supply of ingredients absorbed by the plant from the previously de- composed soil. Mr. Wekey attributed also some other importance to fragments of stones being mixed with the soil, viz., that of pre- XXIV Proceedings. venting it from becoming too tenacious to admit a due amount of oxygen to the roots of the plant. As to other details referred to in Mr. Hodgkinson’s paper with regard to the vine, Mr. Wekey said thatthaying already given his opinion elsewhere in rather a wholesale way, on'this subject, he did not think it necessary to enter into o fils_on this occasion. In concluding, he mentioned, as his opinion, that in places referred to by Mr. Hodgkinson, if due care be taken in selecting a sheltered site, a very much superior wine may be grown than in Brighton and the coast line, where the rapid changes of temperature and high winds act as a great drawback to obtain the object aimed at by some cultivators. Dr. Maund agreed with Mr. Wekey, as to the importance of oxygen being admitted to the roots of the plant, as most conducive to forward its growth. A meteorological table, by Mr. Smyth, of the climatology of the month of June was laid before the meeting. The following is an abstract of the principal observations :— Rainfall, in inches nA ae Hee we «1°84 Evaporation (still water exposed to the sun and air) 2°27 Lowest temperature on the morning of the 12th June, when snow was seen on the Dandenong Ranges... Pa 00 5B «30 OOM Highest temperature on the evening of 1st June... 65° Mean temperature of month ... fd «. 503 Mr. Blandowski exhibited several natural history specimens recently obtained for the Museum, viz. :-— A new species of bush rat, nearly allied to Perameles Obesuda. Lo- cality—near Melbourne. New species of bush mouse. M‘Ivor. The Australian pipit, generally called the Australian lark, Anthus Australis. ocality—near Melbourne. Small sized Australian lark, from Hobson's Bay. The whistling lark of the colonists, nearly allied to Cincloramphus rufescens. Axthur’s Seat. A variety of large sized sponges, from Port Alberton. Boxes of minerals, containing rare specimens from the basalt forma- tion ‘of Victoria, viz.:—Amnalzime, zeolites, wax opal, tripoly, calkspar, magnesite, phonolite, the last being the stone from which the natives prepare their tomahawks. Among the specimens exhibited were some highly interesting fossil remains, obtained from Creswick’s Creek, and forwarded by the President of the society, the Surveyor-General. Mr. Kentish stated that many persons lived at a distance from town, and it would be a great convenience if their evenings of meeting were to be as near the period of full moon as possible. Mr. Gibbons said, that the plan pursued by the late Victorian Institute was to hold their meetings on the first Thursday in each month, which generally occurred at a time when the moon was nearly full. - 5 Proceedings. XXV Mr. Wekey said that such trivial subjects were never brought before a general meeting of the Philosophical Society, and he hoped will not be discussed here. He had no doubt that the wishes of members would be attended to by the council, if referred to the same. Before the close of the meeting, Mr. Wekey addressed the chair- man on behalf of Dr. Mueller, a member of the society. Mr. Wekey said that he was requested to express Dr. Mueller’s thanks for the kindness with which his exertions in connection with the society had been received. He stated that although Dr. Mueller’s absence is uncertain, and his return will greatly depend on the more prosperous state of the colony, nevertheless he expressed his desire to retain his connection with the society. Ur. Mueller hoped to be able to send to the society accounts during his contem- plated expedition to the interior. The Honorary Secretary also intimated to the meeting that the Linnzan Society, of London, to which a copy of the first number of the Philosophical Society’s transactions had been sent, acknowledged the receipt of same, and express their desire to be in communication with the Philosophical Society of Victoria. Several of the members expressed their regret at having lost the valuable services of Dr. Mueller, and it was proposed that in acknowledgment of the services rendered by him to the society he should be elected honorary member of the Philosophical Institute. ete a Leal ite ative ation fudigbux eae adic bine 4 HS, Wve Jk BSOROESS ar aavngi ays. he wee Teta duh ipa Ts om Hye eh: Le alent al i ro ue Be sf wih ‘key ours ah hay Poin EAR Pu Fis Fey. te Tae 5 priitha PD Ng 3 shee Oe hE NS eee ni Age He tgwcleey'y), Yd Rilo iT eRe. Cs a ome ibieh & qt gor ; sane ayes 8; 18 ih, fy: vy ptt Y Oh as opt, om A Wis id. fies soi We ‘ty ite te ACY te: Pave wits i argh RENN clung Mit ie Doe Oe 9 ie shi ba you” Cees 8 ioe ALOU ¥ Bi ea elo ey) men ait WeAtnOee! gah i a) oy il Oo wouikeg MSSUIOK? ’ i fx Tule agi wot eae a Tae ; Tak i i ia x) THE Ahilosophreal Soriety. PATRON: HIS EXCELLENCY THE LIEUTENANT-GOVERNOR. PRESIDENT : A. CLARK, CAPT., R.&., Surveyor-General, M.L.C., de. de. VICE-PRESIDENT : GODFREY HOWITT, ESQ., M.D., F.R.B.S.E. COUNCIL: THE REV. A. MORISON. A. SELWYN, ESQ. DR. F. MUELLER, F.R. BAY. S. J. HUTCHINSON, ESQ., M.D. DR. R. EADES, M.B.F.R.C.S.I. S. IFFLA, ESQ., M.D. F. C. CHRISTY, ESQ., ASSOC. I.C.E. W. BLANDOWSKI, ESQ. TREASURER : D. E. WILKIE, ESQ., M.D. HONORARY SECRETARIES: S. WEKEY, ESQ. B. BROUGH SMYTH, ESQ., C.E. Fhe Philosophical Society. ' MEMBERS: . Captain J. H. Kay, R.N., Honorary Member. Wm. Howitt, Esq:, Honorary Member. J. Black, Esq., M.D. The Rev. Dr. M. Goethe. ‘Dr. E. Davey. J. Greenlaw Foxton, Esq. Balfour Stewart, Esq. The Rev. James Clow. The Very Rev. Dr. Geogehan. E. Wilson, Esq. J. H. Brooke, Esq. F. Acheson, Esq., C.E. Clement Hodgkinson, E:q., C.E. His Honor Redmond Barry, Esq., Acting Chief Justice. L. Becker, Esq. W. C. Rawnsley, Esq., C.E. Major Norman Campbell, Registrar General. C. Pardoe, Esq. The Right Rev. Dr. Goold, C. Bishop of Melbourne. The Very Rev. Dr. Fitzpatrick. The Right Rev. Charles Perry, D.D., Lord Bishop of Melbourne. Sir William A’Beckett, Chief Justice. Dr. W. H. Campbell. 8. Hanaford, Esq. J. Mc Kenna, Esq., M.D. W. F. Stawell, Hsq., The Hon. Attorney-General. Captain Pasley, R.E., Colonial Engineer. William McCrea, Esq., M D., Colonial Surgeon. William Archer, Eisq., A. Registrar General. A. Dobree, Esq. F. Phillips, Esq. A. K. Smith, Esq., C.E., F.R.S. H. C. E. Childers, Esqy., The Hon. the Collector of Customs. William Thomson, Esq. " Ralph Low, Esq, Professor Wilson, Melbourne University. Professor McCoy, 50 92 Robert Sloane, Esq. A. B. Johnson, Esq. Robert Scott, Esq., Corresponding Member. NOTE. aaa Bde ce | PAGE. Ms amipneat Address of the hii ok Reptet: cas R.E,, Surveyor General, &a, &ce o . de IJ. Definitions of ‘Rare or Aitberto Dudes. me Australian Biants: chiefly col- lected’within the Boundaries of the Colony of Vie‘oria, and examined by. ; Dr. Ferdinand Mueller as Bi ie « lif. On the Comparative Value and. Durability of the Building Materials in Use in Melbourne, by Robert Brough Smyth, Esq. wal 4 “24 4 }¥. Definitions of Rare or Hitherto Undescrited Australian Plants, chiefly col-~ lected within the Boundaries of the Colony of Si oe and eaamined by — Dr. Ferdinand Mueller (continued) a oH: pea. V. Personal Observations made in an Excursion cantata aie Central Parts of : Victoria, including Mount SEE NSS mee: and the Black Ranges, by ! Wm, Blandowski, Esq. Vee Fyne SO: sj VI. Original Rules and Tables, ddepted to cases ae Bidélong Ground, in the set- ting Out and Computation of Railway Earthworks, by Clement Mi? ya son, Esq., C, £., Survey Department ine 2 ie iy een <: Vil: Gn the Construction of an Instrument for ascertaining the Mean Tempera- : tere of any place; by Dr, Davey ne ae ie ooneD VIL. Metzorologic’l Observations at Bendigo, by Ludwig Becker, Esq Biase TX. On the Infiveuce of Gravity on the Physical Condition of the Moon’s Surface, - by Balfour Stewart, Esq. ae Es te: 3% X Gi the adaptation of the Eye to the Nature e the Rays which emanate from ~ Bodies, by Balfour Stewart, Esq. tes one oe DS) Xi, Des’ riptive Characters of New supine Pianta: frgm Continental Australia, by Sit] Dr. Ferdinand Mueller fas aA 5 96 | Xi. On the failure of the Yan Yean TEScc embracing an Examination of ‘ne Report of the Committee on the Yan Yean SqEpine) Pe David E, Wilkie, Es., M.D. 4. tee as aes oe we TTT. XIil. The Meteorology of Melbourne, byt Dr. E. Davey fay < Si = cub Ode & XIV: On the probable Influence of Evaporation on the Quantity of Water to be sup: plied by the Reservoir at Yan Yean, by by a Hodgkinson, Esq., C. “3 Survey Department .. eat a ieee vane WE XV. Report of the Commissioners see by the Philosophical Society to in- vestigate the Alieged Insufficiency of Supply for the Yan Yean~ Water Works, by Dr. Wilkie, by Messrs. Fred. Acheson and F. C. Christy ~~ x. 187 | ° _XVI. On the Influence of the Physical Character of a Country on the Climate, by ‘R. Brough Smyth, Esq, Mining Engineer te ee! wie 203 xXVi i‘ A By ce “ption of Fossil Animalcule in Primitive Rocks, from the Upper Yarra Di ‘ct, by William Blandowski, Esq. ua a ee san 221 3 KV. Practica” Remarks oa Hydrometry, by Clement Hodgkinson, Esq. CLE, wi 223 - XIX .On the Primary Upheaval of the Land Round Melbourne, and ‘the Recent Grigin,ot the Gypsum or Sulvhate of Lime inthe Great Swamp between Batman's and Emerald Hilts, Memington, Williamstc wn, and Meibourne ; illustrated by a large number of specimens from that locality, by William Blandowski, Esq. ven oe a nae 6 a XX. On what Data does the City of Melbourne depend for an Adequate Supply of Sik ~ Water from the Yan Yean Reservoir, by David E. Wilkie, Esc., M.D. sa 234 XXI. Remarks on the favourable Geological and Chemical Nature of the Principal Rocks.and Soils of Victoria, in reference to the procuctioa cf Ordinary— - Cereals and Wine, by Clement Hodgkinson, Esq., €.£., Survey Department 260 XXII. Proceedings. XXIII. The Philosophical Society. oe GOODHUGH AND TREMBATH, PRINTERS, FLINDURS LANE.” a a Ke i “ Bes.