250 » REPORT — 1872. 



combining the advantages of apcenite, one, moreover, wliiclx can be so readily 

 moulded into any form and size ■with but small expense and little or no delay, is 

 necessarily applicable to a great variety of uses. The author then made a few 

 brief remarks upon its applicability for ornamental and decorative purposes. 



Besides possessing the several properties which have been described, the apcenite, 

 when prepared with suitable materials, is capable of receiving the most delicate 

 impressions, and by the incorporation of various metallic oxides, any variety of 

 colour can be imparted to it. 



By the use of the native red oxide of iron, manganese, and other mineral 

 substances, artificial marble or granite of almost every description can be produced. 

 These artificial stones, like their originals, are capable of taking an excellent polish, 

 are extremely hard, and can be readily moulded into the most elaborate forms, at a 

 very suiall cost. 



In conclusion, the author submits that, both consti-uctively and ornamentally, 

 apcenite is eminently fitted to meet tlie numerous requirements of the engineer 

 and architect, and to subserve manj' useful and important purposes in the indus- 

 trial arts. 



On Defecating Sewage and Utilizing the Deposit for ilie preparation of Lime 

 and Cement. By Maj.-Gen. H. Y. D. Scott, CB. 



On the Agricidtural Value of the Lime Compounds ohtaincd hy Defecating 

 Sewage. By Maj.-Geu. H. Y. D. Scoii, C.B. 



On the Selenitic Method ofmaJciiuj Mortar. 

 By Maj.-Gen. H. Y. D. Scott, CB. 



On an Apparatus for testing the Water-stopping efficiency of Clay Soils and 

 other Substances under various wressifres. By John Smytu, Jun., A.AI., 

 M.I.C.EJ. 



The author, when engaged in 18G7 in repairing a leak in the piincipal embank- 

 ment of the reservoir for supplying the river Bann in Irelnnd (see Transactions of 

 the Institution of Civil Engineers of Ireland, vol. ix. page 51, " An Historical 

 Sketch of the Construction, Working, and Repair of the Bann Eeservoir"), was 

 obliged to make experiments on the capabilities of peat, clays, and soils in stanching 

 water, and felt the want of an efficient apparatus for the purpose. Subsequently, 

 after making more experiments, he was led to devise the apparatus of which 'a 

 diagram was exhibited. The instrument consists of a cylindrical chamber 6 inches 

 in diameter, 3 feet deep, provided at the bottom with a perforated plate, which 

 allows aU leakage to pass away, and at the top with another plate into which is 

 screwed a 1 inch in diameter iron pipe, made of such length as the position of the 

 instrument and the pressure to be experimented with will allow. Two narrow 

 glass windows, 2 feet long by ^ inch wide, are provided on opposite sides of the 

 cyUnder, by which to observe the behaviour of the substance under experiment 

 First a layer of gravel is put in to cover the holes in the bottom plate, next the 

 experimental substance is rammed in, and next another layer of gravel. The 

 author has tried experiments on 1 foot deep of peat, and found that although at 

 first the leakage is increased by increase of pressure, yet when the pressure is kept 

 constant it soon diminishes even with clear water; in new embankments the 

 water passing through would be muddj-, and likely to diminish the leakage much 

 sooner. The author intends to make more experiments, and in the mean time 

 commended the instrument to the notice of the Section as likely to be useful to 

 those engaged in the construction of waterworks. 



