was the heaviest was adjusted by thrusting the point by means of the before mentioned screws nearer to the centre of the beam. When it was correct or very nearly correct I took off the scale pans and reversed them by placing them on the opposite ends of the beam, and on trying them in this position I found they gave the same indication, which was a proof that the two scale pans and weights were equal, and one not heavier than the other. After a whole day's trial however I found I could not adjust to perfect accuracy and so I left the balance out of equipoise about th of a grain in 100 grains. This error is equal to the 50,000th part of the weight which is quite accurate enough for even delicate purposes, but the error being known it is obvious that subtraction or addition is all that is required in order to arrive at a perfectly correct result should a greater degree of accuracy be required.

13. Figure 8 represents my third balance which is adapted to weighing quantities from 100 to 2000 grains. Though not so sensible in its indications as the last described balance, it is fully adequate to most experimental purposes falling within the weights just specified. Its sensibility at first was very great but having been in considerable use its delicacy of indication has become considerably diminished; 3dths or the 50th part of a grain however, still gives a decided result with 2,000 grains in each scale which is equal to the dth part of the weight. Sir M. Farraday in his chemical manipulation tells us that a balance is an exceedingly good one if it indicates to the 50 or 60 thousandth part of the weight.

14. It will be perceived by Fig. 8, that the central portion of this balance which is represented of the real size, is exactly similar to the last. It requires therefore no description, the former description in Para. 10, will answer for both. The means of adjustment, however, and the bearing points are different. The balance is equipoised before using it, not by a small moveable wire as g, figure 2, but by means of a small ball a, screwing along the wire b, b, figures 9 and 10:---and the bearing or suspending points at each end of the beam are double. Fig. 9, is a plan, and figure 10 is a front view of the manner in which the points are fix

ed: these views are sketches of the left hand end of the beam, or the end opposite to the pointer end. In both figures c, and d, are pieces of brass, the piece d, being firmly and securely fixed in the end of the beam, and the piece c, sliding in a groove and having liberty to move a small space to and fro as shewn in fig. 10. Small screws e, e, pass through the brass d, and thrust the brass c, which carries the points, towards the fulcrum; the wire b, fig. 9, has a shoulder abutting against the end of the beam, and passing into the beam is screwed and tapped into the brass c, so that when the screws e, e, are loosened this screw acts in the opposite direction or pulls back the points away from the fulcrum, the brass c, having liberty as before stated to move to and fro in the groove; it is evident therefore that this contrivance is competent to the adjustment of the balance, although the brass carrying the points at the other or pointer end is permanently fastened in the beam. I have only to add that f, in figs. 9, and 10, is a tightening screw, to fix more securely the brass c, after the adjustment has been effected. The adjustment was made as before, only with 1000 instead of 100 grains lin each scale.

15. The scale pans are supported in the manner exhibited by figure 11; the points enter small polished concavities in the screws a, a, as described in figure 7, Para 11. (which see.) I have adopted double points because the weights for which this balance is used are heavier, and because they are more convenient in practice, there being no wandering, or twisting of the scale pans. My fourth balance is precisely similar to the 3rd only stronger and calculated to weigh from 1000, to 10,000 grains. J. B.

V.-* Astronomical Tables and Observations. By Goday Vencat-Juggarow.

To the Editor of the Madras Journal

SIR,

of Literature and Science.

I have often heard it remarked, that this is an age of improvement in every department of knowledge; whatever may

We have much pleasure in giving insertion to the following letter and its accompanying tables, the calculation of which would have reflected credit, on the talents and industry of a member of an Eu

be the case with respect to other countries, I am sure that this observation is peculiarly applicable to India; it was from the general desire for information which has lately actuated my countrymen, that about 18 months ago I selected the divine science of Astronomy as the study and pursuit most congenial to my disposition and best calculated fully to occupy my attention as it had fortunately fallen under my notice that many persons very imperfectly acquainted with the mathematics appeared (notwithstanding their persual of the works of many eminent writers on Astronomy) to be unable to comprehend even the leading principles on which it is founded, I next resolved to aspire above a mere general idea, and to obtain a more than superficial knowledge of the I comsublime mysteries of the science; for this purpose menced a regular study of Euclid, Algebra, &c. and lately have acquired a considerable degree of practical as well as theoretical knowledge, and in proportion as I have increased my stock of knowledge, in the same degree has my desire for further improvement and making myself useful increased; it was from this feeling that on a late occasion when my friend the Hon'ble Company's Astronomer was so obliging as to explain to me the means adopted by Astronomers for predicting the Eclipses of the Sun, and Occultation of the fixed Stars, that the possibility of constructing a table to facilitate the computation occurred to me, the result of a little reflection and some labour has produced what I desired, which I have taken the liberty to beg you to insert in the Madras Journal of Literature and Science; this table with the assistance of the Nautical Almanac will afford a ready means of discovering when occultations will happen, and persons possessed of a Telescope and Regulator will be enabled to determine the longitude to a very great degree of ropean university, and which are deserving of particular admiration and praise, when considered as the production of a native of this country, who must have laboured under peculiar disadvantages in studying the difficult though interesting science of astronomy in a foreign language. We trust that the distinguished success, which has attended the labours of Goday Vencat Juggarow, may serve to encourage his countrymen in the prosecution of the study of this, and the other branches of science, and we hail this display of talent as a bright specimen of "the march of mind" among the members of the native community of Southern India.-ED.