compass, as it does not show very strong from seaward, only from South by East.* I mean South by East from the beacon. However, none can approach the harbour without seeing the light shown from the beacon or perch.-(Signed) JOHN URIE, Stornoway, 23d March 1853.

1st, I saw the beacon light quite distinctly, making the Stornoway Harbour.

2d, I consider the beacon light most useful in a dark night rounding the rock.

3d, I have to offer no suggestions for the improvement of the beacon light.

4th, I have seen it both in good and bad weather.

5th, I consider such as the beacon light of importance on all such rocks on the British coast.-(Signed) JOHN Morison, Master of Mail" Packet."

STORNOWAY, 26th March 1853.

SIR,-In answer to the inquiries respecting the beacon light, I have to say ;—

1st, That I saw it distinctly at a considerable distance on two occasions, one on a very stormy, dark night, and also last night, which was a clear moonlight night.

2d, Its utility is unquestionable.

3d, I am not scientific enough to suggest any improvement. 4th, This is answered in my answer to the first inquiry. 5th, There is no doubt of such a beacon light being highly useful on any rock where it could be adopted.-(Signed) J. MACDONALD, of the "Kover's Bride."

GRANTON, December 6, 1853. Steam Tender "Pharos."

SIR,-According to your request, Mr Watt and I beg leave to state, that the greatest distance we have seen the apparent or reflected light upon the beacon which is placed upon the reef that lies off Stornoway lighthouse, is, as near

This is to some extent occasioned by the oblique incidence of the light near the sides of the lantern upon the outer glass, and the objection arising from that cause could easily be obviated by making the glass cylindric with its centre of curvature coincident with the focus where the rays are re-assembled.

as we can judge, about one mile from a S.S.W. direction, and three-quarters of a mile from a S.E. direction. We have had several opportunities of observing it while approaching Stornoway Harbour in dark nights, and have decidedly found it of great benefit, especially as we have found ourselves previous to this light being exhibited within two cables' length from the beacon, and could not see it distinctly in consequence of the narrow entrance being darkened by the high land. We can now run with safety and confidence, knowing that we can pick up the apparent light on the beacon at the above distances in the darkest nights, and we consider that it is a benefit to all shipping that frequent the harbour of Stornoway.-PETER ANDERSON, Captain; WILLIAM WATT, Mate. TO THOS. STEVENSON, Esq., &c. &c.

STORNOWAY LIGHTHOUSE, 15th April 1853. I beg to send you the few remarks I have obtained regarding the beacon light. I have called on all I know had a fair opportunity of seeing and remarking on the light at night. Fishermen and small craft think the light on the beacon of more advantage to them than the light in the lantern ashore. When the sea breaks on the beacon the power of the light reflecting on the spray is seen at a considerable distance. When standing on the road about sixteen yards from the Tower door, about W.N.W. from the beacon, and when entering the loch, bearing about S. or S.S.E. from the beacon at these two points, the light on the beacon is about as powerful as one of the old mirror reflectors (formerly used for lighthouses). At other points where the light is seen, it appears like an ordinary ship lantern. All agree that the light on the beacon is most useful, and especially if it could be constructed so as to be seen at other points, the same as the two I have mentioned.*-(Signed) ALEX. CAmpbell.

STORNOWAY, 4th January 1854.

We hereby certify, that we entered the harbour of Stornoway at night, and found the light and beacon most serviceable

* Vide Footnote, p. 279.

in making the harbour. We saw the light distinctly fully a mile off, the weather being various at the time.-(Signed) MURDO M'LEAN, Shipmaster; JOHN M'KENZIE, Shipmaster; JOHN M'LEAN, Shipmaster.

SCHOONER" NORGE," 9th May 1853.

1st, I saw the beacon light distinctly at a distance.

2d, I consider the beacon light very useful.

3d, I consider the beacon light could not be placed better. 4th, I lay-to off the lighthouse all night with a strong breeze and thick weather, and found the beacon and lighthouse of great service.

5th, I would recommend similar lights on all rocks round the British coast where such could be established.—(Signed) P. P. STRAND, of the schooner "Norge" of Drunton, Nor

way.

BRIGANTINE "THOMAS" OF BELFAST.

This is to certify that I was riding off the lighthouse of Arnish for three days, during a gale of wind from N.N.E., light bearing N. by W. half W., one mile and a half distant, and that I saw the reflection of the light on the beacon very distinctly every night, and consider it of great service to vessels entering this harbour.-(Signed) JOHN KEAY, Master. STORNOWAY, 31st December 1853.

REPORT OF THE COMMITTEE appointed by the Royal Scottish Society of Arts on Mr THOMAS STEVENSON'S paper on Dipping and Apparent Lights.

Your Committee having met and carefully considered the papers remitted to them with the relative drawings, and a letter from Mr Stevenson in farther elucidation of his views of the subject of dipping lights being rendered available during fogs, have now to submit the following report :

Your Committee are fully impressed with the importance of the subjects discussed by Mr Stevenson, and agree with him in his doubts as to the feasibility of using, effectively, phosphorescent oils to illuminate any insulated point, and as to the risk of failure attending the use of gas pipes and electric wires for such a situation.

As to the dipping-light, they are of opinion that where the lighthouse is sufficiently elevated, it may in many cases be made available by using

cither one light, or two in a line, when that is practicable; and that in the case of fogs, a light by being depressed may often be made available for a vessel in a position too near to see the horizontal light distinctly, but still far enough off from the danger to have warning given in sufficient time to avoid it.

They think, however, that it would be attended with danger to allow the light-keeper the discretionary power of depressing the ordinary light, for fogs sometimes clear off so quickly, that the ordinary light might be suffered to remain depressed after it could have been seen at a distance, and ought to have been set again in the horizontal position, so that vessels might be misled by its having been withdrawn; and they therefore think that a separate light, and of a different colour, ought to be provided for the purpose of being depressed, as shown in Mr Stevenson's drawing for the application of a depressed light to indicate the position of a rock.

As to the Apparent Light-Your Committee think that this is a beautiful and ingenious contrivance, and that it may be applied efficiently in many cases where it is almost or wholly impracticable to employ a direct light. They see no reason to doubt its practicability; and if there had been any doubts before, they would now be entirely removed by the suc cessful result of the experiment at Stornoway.

They see the difficulty of making the apparent light nearly as brilliant as a direct light, though they do not despair of improvements being made in the details, so as to increase the illuminating power.

Still, admitting that the illuminating power were to remain decidedly inferior, and that the apparent light could not be seen at any great distance, it must be borne in mind, that for a vessel at a great distance it is quite sufficient to see and steer for the direct light; and that it is time enough to alter the course upon coming within such a distance as that the apparent light shall have become visible.

Mr Stevenson discusses the practicability of illuminating buoys by an apparent light, and there does seem to be reason in what he says as to the less steady and powerful light from a buoy, owing to its constant change of position, being in some measure made up for by startling scintillations; nevertheless there can be no doubt of the greater difficulty in illuminating a floating buoy than a fixed beacon.

It appears, however, to your Committee, that even if it should be found impracticable to light up buoys thoroughly in this way, still that a blaze of light thrown on a large white buoy might make it visible at a considerable distance; at all events, to such a distance as, considering that the main light is visible and its position known, may be sufficient to point out the place of danger before coming too near to avoid it.

In conclusion, your Committee have to express their opinion, that the paper is deserving of the highest commendation of the Society.

JAMES LESLIE, Convener.

PHILIP KELland.

WILLIAM SWAN.

EDINBURGH, 9th February 1854.

On Collodion Calotype. By THOMAS RODGER jun.,
St Andrews.*

Agreeably to the desire expressed by the President of this Society at a late meeting, to be furnished with the modes of operation employed by those who practise photography, I now beg leave to submit to the Society the following remarks on calotype :

In the practice of a new and difficult process, the success of which depends on a number of minute details, which, though they admit of variation, require very nice adjustment, there is much room for ingenuity and improvement. The process of calotype is of this nature, and in the practice of it, many circumstances, of themselves apparently unimportant, frequently occur to prevent success. Hence it is of great importance to simplify the process and render it more certain in its results. These objects I have endeavoured to attain ; and, in the following account of the calotype process, my aim will be to detail shortly that process as practised by myself with considerable success and certainty. I shall do so, however, without reference to the modes adopted by others, leaving it to the society to compare the various methods at their convenience.

All the former modes of calotyping have been superseded by the process of collodion on glass plates. The superiority of the latter process will be apparent to every one on a very slight comparison of the results easily procurable by this process, and the most successful results of the old paper process.

Wonderful and beautiful as the pictures by the paper process were considered a short time ago, those by the glass plate process have quite outstripped them, for rapidity of execution, minuteness of detail, for expression, and beauty of finish. It is therefore to this process alone that I confine my remarks.

I need not make particular allusion to the camera, stand,

*Read to the Society February 1854.