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As the weight on each of the beams is proportioned to the distance between them ; and as the strength of the beam is proportioned to its breadth : tl.e breadth in inches, as marked in the first column of the table, must be multiplied by the distance in feet between each beam, measured from centre to centre for the breadth of the beam ; or, if the breadth of the beams are given, the distance in feet between themis found by dividing their breadth by the breadth in the first column of the table.
A room, 22 feet by 33 feet, has to be roofed in, the timbers provide _
for which are round, 18 inches diameter in the middle, and 25 feet long. It is required to know the most economical manner of cutting them up, the scantlings of the beams, and their distance apart.
The stitfest beam that can be cut out of an 18 inch tree is 9 X '15, or if cut into two timbers. 4% X 15, to ascertain if this timber will be so thin as be liable to break side-ways, the rule for this purpose ‘ .6 X 22 __ 13.2 “~7.T- W breadth; the beams 4% X I5, are therefore not too thin. By referring to the table, under 22 feet length of bearing, a depth of 15 inches requires a breadth of l% inches. The breadth of the timber, 4%, being
will be applied as follows:
divided by 11, gives3 ft, thedistancefrom centre to centre of the beams ;_
this distance gives 11 spaces, or 10 beams, or 5 timbers in the 33 ft.
_ The timbers of the dimensions above stated could be cut inw tW0 beams 12.7 x 6.4, having a greater section than that given above,
15 X 4%; but on a reference to the table in. the column of 22 feet
length, and 129 in depth, the breadth is 2% inches, and 6'4, divided by 2'5, gives 2 feet 8 in distance from centre to centre, if beams requiring l2§ spaces, or 12 beams, or 6 timbers. ~ 2nd Example. Beams 8% X 12, having been provided for a roof of 22 feet span—— @ required to know the distance they are to be placed apart. In column of 22 feet span, opposite a depth of 12 inches, is a breadth of 3
inches, and 8% divided by 3, gives 2 feet 10 inches as the distance
from centre to centre, at which the beams ought to be placed. 31-'d Example.
' Proposed to roof at room 18 feet wide, with timber placed 1 foot 3 inches from centre to centre, so as to be covered with tiles instead of burgahs, the deepest timber procurable being 9 inches, required the breadth of the beams.
In the column of the span of l8 feet, and a depth of 9 inches, the breadth is 4 inches, which multiplied by 11, gives 5 inches for the breadth of the beam. ~ J. T.
CXII.-—On the Temperature of Deep Wells to the west of the Jamna. By the Rev. R. Evsnnsr.
During the last cold weather and the present, I have paid some attention to the temperature of wells in the country to the west of the Jumna. They are not usually more than 30 or 40 feet deep within a few miles of the river, but beyond Rhotak, about 50 miles to the west of this, on the road to Hansi, they are not less than IN} or 120 feet deep, and, in one instance I have met with (that of the fort at Hansi) 160 feet. Farther than that I cannot speak from exami-, nation, but all accounts agree in stating those in the Bikanir country to be the deepest, probably not less than 350 feet. I have almost invariably found the temperature to increase with the depth, but the increase is modified by three circumstances. _.
lst. By the locality, as in the case of a pool of water being near, or the mouth of the well being broad in proportion to its depth, both which causes tend to lower the temperature in the cold weather.
2ndly. By the season of the year at which the observation is rnade. The tendency of the rains is to reduce all wells to the uniform temperature of 78°, which is about that of the rain-water when it falls. From this cause the deep wells are at their minimum about the autumnal equinox, and get warmer during the cold weather. On the contrary, the more superficial ones become colder during the same period. '
3rdly. By the quantity of water that is drawn from them. Those that are not used are usually the lowest, and those ‘where oxen are working for the purpose of irrigation by a great deal the highest. I have only to premise further that the mean temperature of the year here, according to Major OL1vEn’s observations, is 76°. The general results I have obtained are as follows:
No. of wells. Depth to bottom. Temperature at the bottom. ‘ _ 1. Mean of 10 observations made at nearly equidistant pe- feet.
The increase in Europe is said to be 1° centigrade, or 1°‘ 8 Farht. _for every 35 or 37 metres (about 105 or 110 feet English), of depth-_. Werel to select from my observations those made where bullocks
‘ were working for the purposes of irrigation, the increase would be
much more rapid than what I have above stated. Thus:
I do not publish these observations with the idea that they are sufiiciently numerous to establish any general law on the subject for this country, but because my avocation here does not permit me to extend them, and in the hope that some one who may hereafter travel through the Bikanir country may be induced to take up the subject, for there alone can any considerable depth beneath the surface be attained.
P. S.——Lieutenant TREMENHEERE, of the Engineers, in leaving this on the Shekawatti campaign, had the kindness to promise that he would make some observations on the temperature of the deep wells that lay in his route, and this he has performed with great zeal and assiduity. He has now placed the results he obtained in my hands, and I have drawn up the following abstract of them:
These observations were made throughout a large tract of country lying between 28 and 26“ N. Lat. and 78 to 76° E. Long. And the time of the year in which they were made was from the 26th October to the 28th February. The mean temperature of the year for the surface may be reckoned at 7 5°, if, as stated by Lieut.-Col. OLIVER, that of Dehli be 73°. 4. ' '
I see that in the above paper on this subject I have misquoted this same‘ datum of Colonel OL1vEa’s, calling it 76°. I took the number carelessly from the wrong column, owing to its suiting so well to Dr. RoYLn’s observations at Seharanpur, who makes the mean of that place, I believe, 73°. 5. One or other of the two observations must
U Musooree (Masi/fri.) By S. M. Bouwnason, Esq.
1834, Therm. Bar. attd. detd. From 15th to end of May, 8 observations at 10 A. M. 23.919 75 78.l"‘ 9 ,, at 4 P. M. 23.894 75.6 79.5‘ -: 10 ,, at 10 P. M. 23.905 74.8 75.7
Mean temperature at 10 A. M. and 10 P. M. 76°9. Bar. at 4 P. M. compared with 10 A. M. Bar. at 4 P. M. compared with 10 P. M.
Mean dzfil greatest. least. Mean diffl yreatert. least. (6 obsrs.)—0.043 -0.060 -0.026 (7 obsrs.)—U.0;54 —0.066 0.004 Therm.
Bar. attd. detd. June,........... .......25 observations at 10 A. M. 23.897 71.8 70.3 22 ,, at 4 P. M. 23.815 71.4 71.1 23 ,, at 10 P. M. 23.870 71.5 68.0
* I think that the temperature at 10 A. M. and 4 P. M. was considerably raised by reflection. This was modified or obviated in the subsequent months.
Bar. attd. detd. September,. . .. . . . . .. . . 25 observations at 10 A. M. 23.994 67.7 67.2
October,. . .. .. .... . .. . . 23 observations at 10 A. M. 24.084 61.5 62.2 19 ,, at 4 P. M. 24.012 61.5 61.96 20 ,, at 10 P. M. 24.050 61.8 58.63 Mean temperature at 10 A. M. and 10 P. M. 60°41. Bar. at 4 P. M. compared with 1.0 A. M. Bar. at 4 P. M. compared with 10 P. M. Mean daft greatest. least. Mean diffl greatest. least.
Bar. T. attd. ‘detd. November 1st to 21st. . . 17 observations at 10 A. M. 24.158 57.5 57.4
Mean of the mean temperatures from 15th May to 21st November, 66°17.
3lstAugust,.........................................feet 6287.5 By mean of 49 observations, at 4 P. M. do. do. .. ,. .. .. .. .. .. 6285.9
By mean of 30 ditto, at10 P. 14. July to August, ..... .. .. .. .. ... 6274.7
By 61 observations, Caineville above Seharanpur, . . . . .. . . . . . . . . . 5346.7 Sehlaranpur above,Calcutta, .. .. .. .. .. .. .. .. .. 1012.3
XIV.—Pr0ceedi1igs of the Asiatic Society.
Captain M. G. \Vn1'r1=.', Senior Assistant Commissary, Arracan, proposedat the last Meeting, was duly elected a member of the Society.
Professor LEA and Dr. R. HARLAN, of Philadelphia, pro osed as honorary members at the last Meeting, were upon the favorab e report of the Committee of Papers, halloted for and duly elected.
Read the following report of the Committee appointed, at the last meet-_ ing of the Society, to consult with the Baron Huoni. on the expediency and on the best means of procuring from Europe a competent Curator for the Museum. ‘
“ Although the measure of sending to Europe for a qualified curator would ensure the establishment of a museum in Calcutta, upon a footing such as has not hitherto been known here, and perhaps on a par with those in more favorable climates; and although the unexplored and extensive field around us promises an ample store of novelties, such as would render our museum in time am object of
attention to naturalists both here and at home, still it cannot be conoealedithat,
there are several points of view under which the scheme of procuring a curator from Europe does not appear the most favorable for the end to be accomplished.
“ The Baron HUGEL has favored the Committee with his opinion. that a competent naturalist, that is, a person acquainted with the branches of Zoology, might; be induced to accept the situation on a salary of,200 rupees a month. By making this sum payable from the day of his embarkation from Europe, a separate allow. ance for passage money and outfit might perhaps be obviated, and a similar pro4 vision might be made in case of his return home : The Baron’s recommendations through his friends at Vienna or Paris, would also be a guarantee that the person selected should meet the Society's expectations, and faithfully perform the duties assigned to him, while health should last: but he must necessarily incur much expence on his leaving his own country; he would here be altogether dependent on the Society in case of sickness, or he might become a burden, were he to prove inadequate to perform his duty. It could not he expected that the same individual should be a mineralogist or a geologist: these branches therefore (and they are important to us,) would still be deficient. Again, though he might learn a little English on his way out, he would hardly be able to write descriptions, for publication, of the new objects of Natural History, which might fall under his notice.
“ These considerations have led your Committee to listen favorably to a modification of the original plan, which offers the opportunity of providing a curator on the spot.
“ Dr. Pnnnson, your late honorary curator, in resigning this situation a short Lime since, stated that he had found it impossible to do much hitherto for the
scum, while acting gratuitously: his distance from the premises : his attention
to his own collection, naturally interfered to prevent his attention being given to a. '
secondary object. These difliculties would however be in a great measure removed were he to receive such allowance as the Society might determine to devote to the purpose of creating and maintaining a museum : indeed he would be willing to accept the oflice at 150 rupees per month, which would be a positive saving of 50 to the Society, a material consideration in the actual state of its finances : This sum would enable him to take a house near thespot, orto procure the means of conveyance till he could get one suitable : it would purchase as it were his exclusive services : for it he would consent to relinquish the further prosecution of his own private collection, and to devote his whole leisure to the Society's museum. On the other hand, being in the Company's Medical Service, he could at no time become a hurthen to the Society, which would be at liberty to annul its engagement with him at any time, should a fair trial prove that the object of forming a creditable museum was not attained, or was no longer desirable.