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THE CIVIL ENGINEER AND ARCHITECT’S JOURNAL. [Jan. 6, The following is Mr. Laurie’s description of the in strument. The drawings give the details of the appa ratus.—J. S. R.. The fact that the specific gravity of salt water is greater than that of fresh, and that it increases with the degree of saturation, is what the operation of this instrument depends on ; by its means two columns of water, the one feed and the other brine, are poised against eacli other, so as that any difference of weight betwixt these columns immediately becomes apparent by the lighter of the two requiring an accession in quantity to resist the upward pressure to which both columns are subjected. This is accomplished by having two common glass gauge-tubes close together, each of which is connected with a separate tube; that inside the boiler descends to the level of the water, the spe cific gravity of which is to be measured, and having either or both of these tubes so connected with the feed-pipe of the boiler, that by opening a cock one of the pipes will be filled with feed-water, while the other remains filled with brine, which cock being shut, the tubes remain so filled ; but inasmuch es feed-water is of less specific gravity than brine, it will be forced up and stand in the glass tube at a higher level than the brine, which difference of levels increases with the saturation—and hence the index to judge of the salt ness. Fig. 1 and 2, A, B, are the two glass gauge tubes; C, one of the tubes forming the connexion betwixt one of these glass gauge tubes and its tube D, that descends inside of the boiler to near the bottom; E, the tube forming the connexion betwixt the upper ends of these tubes and the inside or the boiler and ascends to near the top; F, G, two cocks so made, as shown in the drawing, that by their means each of the tubes inside of the boiler may be shut off from the glass tubes, and also may be connected with the tube H, leading from the feed-pipe of the boiler; I, a cock affording the means of shutting off the tube E from the glass tubes, and also of connecting either of these glass tubes with the tube K, leading to the bilge of the vessel; each of these cocks has a handle, and when the instruments indicat ing, the three handles hang perpendicularly downwards. To bring the instrument into operation, the three handles must first be put in the position j \ which has the effect of allowing the brine to flow right up the glass tube A, and out through the tube K, into the bilge of the vessel; this having been done for so long a time as that A and its tube inside the boiler be thoroughly cleansed and filled with brine, the handles are then to be put in the position i which, in like manner, cleanses and fills B and its tube inside of the boiler with brine; finally, bring the handle of the top cock into its original position, and put either of the lower handles horizontal, which forming a connexion of the feed-pipe with one of the tubes inside of the boiler, fills that tube with feed-water; thus there are in the two tubes inside of the boiler two columns of water of different specific gravities, the one being brine, the specific gravity of which is to be measured, and the other feed- water, the specific gravity of which is pretty nearly constant, so long as the temperature of condensation is the same, and does not vary much, let the j temperature of condensation be what it may; but, inasmuch as these columns of water are of different specific gravities, the pressure on the bottoms of ; them will force the lighter up the glass tube, until such a quantity of brine has followed it as makes it of equal weight with the other; and hence, in the two glass tubes, the water stands at different heights, the magnitude of which difference becomes known by means of the scale fixed betwixt the glass tubes, and therefore also the degree of saturation of the brine. The use of this instrument, which might be called a Salinometer, is not confined to this one subject, for it answers thoroughly all the purposes of the common glass gauge, the position of the surface of water in the boiler being midway betwixt the surfaces of water in the tubes. When either or both of the glass tubes is broken, put the handles in the position !!, and nothing can escape from the boiler. T. W. L. CHURCH BUILDING IN IRELAND. It at all times affords us much pleasure to notice the works that are in ! progress in Ireland, particularly when we have to record buildings of a public j character, such as the one we are about to describe; for the description, to gether with the preceding remarks, which are slightly abridged, we are 1 indebted to the Newry Examiner. The architect is Mr. Duff, whose eccle- ; siastical works we have before noticed in this Journal. We hear of continual comparisons between England and Ireland, in which the relative prosperity and poverty, civilization and crime, learning and igno rance of these two countries, are descanted upon with no small share of skill. There is, however, one prominent part which these balances of national cha racteristics have, either through inattention, or incompetence to do justice to the subject, left almost unalluded to. This is the more to be regretted, as j nothing more tends to introduce good feeling between countries, and a sense of emulation, than judiciously pointing out to the less improved country the causes and consequences whereby the more cultivated has arisen in emi nence. England has been remarkable for the richness of its churches since imme diately after the conquest, when William, the Conqueror, with arms, intro duced arts, and when the simple strength of Saxon edifices was supplanted by the more stately splendour of Norman towers. The temperament of these hardy Normans must have been more than tinctured with piety. They must have been essentially devout, for, whilst we find the castles of their nobles of comparative plainness, in no instance does aught beneath grandeur suffice them when they erected temples of religious worship. This may be accounted for by the prevalence then in repute of joining the priestly functions and ar chitectural duties in the one person. The churches of England are almost all constructed after the designs of bishops and priests, and, perhaps, never again may the world expect to behold Gothic architecture carried to such perfection as when such men as William of Wykeham, though wearing the sacred purple, deemed them sanctified duties to resign, with compass and square, inspect stone-hewers, learn the relative bearing of timbers, and, in a word, all but became artisans, by spreading out the protecting span of roofs, and by sheltering civilised society. Unfortunately for Ireland, its distracted state of society, ever in a turmoil between the invader and the invaded, afforded no shelter for arts to thrive. Hence its almost total want of magnificent churches; and Christ’s and St. Patrick’s in Dublin, and Armagh Cathedral, may be said to constitute the only pious preserves of ancient days. Better times are upon us now, and church building, within these last twenty-five years, durably marks the vast spread of civilization, learning and religion, which have come, as it were, in well regulated abundance upon the people. More Catholic churches have been built in Ireland within that period than were for the preceding two cen turies ; yet few of them are in the Ecclesiastical or Gothic style of architec ture. Dublin has been especially blameable in this respect, and out of the hundreds of thousands sterling, its citizens dedicated to erect houses of wor ship these last ten or fifteen years, we look in vain for a Gothic building ^