262 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



[AtJSUST, 



the assembly of the people is of much interest in an historical sense, 

 but not immediately relating to the end we have in view, we are com- 

 pelled to omit it. 



In the '21st chapter is mentioned the diversion of the Nile during 

 the war between the Persians and Egyptians. 



BLOCKING I'l' OK THE EURIPeS. 



In his 13th Book our historian describes the measures taken by the 

 inhabitants of Euboea on their revolt from the Athenians. This island 

 being separated from the continent only by the narrow strait of the 

 Euripus, they solicited the Beotians to assist then) in stopping if up, 

 in order that they might receive assistance against any attacks from 

 the Athenians who were masters of the sea. To this the Beotians 

 agreed, and all the cities set upon the work, and everyone strove with 

 diligence to perfect it, all the citizens, foreigners and strangers being 

 set to work. The mole began at Chalcis in Eubcea on one side, and 

 at Aulis in Beotia on the other, that being the narrowest part. In these 

 straits the sea was very boisterous and rough, but after this work much 

 more unquiet and raging, the passage being made so very straight and 

 narrow, that only one ship could pass througli. There were forts built 

 on both sides upon the extremities of the moles, and wooden bridges 

 made over the currents for communication. 



CARTHAGTXIAN EN'GIXEERIXG. 



Our author gives an account of several sieges by the Carthaginians 

 in Sicily, who appear from his account to have been as skilful as the 

 Greeks in military warfare. At Oie siege of Himera in Sicily, Hannibal 

 the elder (Book 13th), undermined the walls, supporting them with 

 great pieces of timber, which being set a-fire, a great part of the walls 

 suddenly fell down. 



In the 20th Book, in the account of the expedition of Agathocles 

 into Africa, there is a description which mentions, the country as 

 well irrigated and supplied with canals and sluices. 



JIACEDO.N'IAN GOLD MINES. 



Philip, King of Macedon, (Book 16th), having taken Crenidas, and 

 called it Philippi, so improved the gold mines in those parts, which 

 before were but inconsiderable and obscure, that by building of houses 

 for the w orks he advanced them to bring in a yearly revenue of above 

 a thousand talents. 



ALEXANDER THE GREAT. 



The siege of Tyre by Alexander the Great, recounted in the IGth 

 Book, required the execution of works on a very great scale. Alex- 

 ander demolished Old Tyre, as it was then called, and with the stones 

 carried by many thousands of men, raised a mole two hundred feet in 

 breadth across the sea, width by the help of the inhabitants of the 

 neighbouringcities, who were impressed for the purpose, was speedily 

 carried out a considerable way. This mole was afterwards injured by 

 a violent storm, when Alexander caused it to be repaired with trees 

 laden with earth, and so again brought it near the city. By this and 

 many other operations he was able to take the city, after a gallant de- 

 fence, in which the inhabitants displayed much ability. 



In the memorandum books of Alexander examined after his death, 

 (Book !&th),were fou .d heads of six colossal plans, among which were 

 the following, — that a plain and easy road siiould be made straight 

 along the sea coast of Afnca to the Pillars of Hercules, that sis mag- 

 nificent temples should he built, and that arsenals and ports should be 

 made in places convenient for the great navy he contemplated. These 

 things, although highly approved by the Macedonians, yet because 

 they seemed things beyond all measure impracticable, were desired 

 to be laid aside. 



INUNDATIONS. 



During the Seleucian war, (Book 19th), the Macedonians under 

 Eumenes encamped on the banks of the Tigris, about three hundred 

 furlongs from Babylon, Seleucus occupying the river with a flotilla of 

 small vessels. The Seleucians, having sailed to au old water course, 

 cut down the banks at a part where it had been filled up from length 

 of time, ujicn this the Macedonian camp was surrounded with water, 

 and all the tract of ground overflowed, so that the army was in great 

 danger of being utterly lost. At last removing a great part of his 

 army in fiat bottom boats, he caused all the Macedonians to repass the 

 river, and then for the purpose of recovering his carriages and baggage, 

 by the direction of one of the native inhabitants, he set about cleansing 

 such another like place, by which the water might be easily diverted, 

 and the ground all round about drained dry. When Seleucus per- 

 ceived this he granted a truce, and the works were suspended. 



In the same book is the account of the natural inundation, bv which 

 tlic city of Rhodes was so much injured. Rhodes being built in the 

 form of a theatre, and the rain very heavy, the water ran for the most 



part into one place, and the lower parts of the city were presentlv filled 

 with water, for the winter being looked upon as over, no care had been 

 taken to cleanse the channels and sewers, and the pipes likewise in 

 the walls were choked up, so that the water stood several feet deep, 

 until part of the city wall breaking down, the pressure was suddenly 

 relieved, 



PILEWORK. 



In a mention of the Cimmerian Bosphorus in Book 20th, it is related 

 that the king's palace was surrounded with the river Thasis, and that 

 there was a road to it through tlie fens, guarded with forts and towers 

 of timber, raised upon pillars over the water. 



DEMETRIUS POLIORCETES. 



We find in the 20th Book a long account of the siege of Rhodes by 

 the celebrated Demetrius, who among other works made extensive 

 mines under the city walls, which being told to the Rhodians, by a 

 deserter, the Rhodians made a deep trench along the walls, which was 

 now ready to be tumbled down, and forthwith fell to countermining, 

 and at length met the enemy under ground, and so prevented the mine 

 from proceeding any farther. 



MR. MUSHET'S PAPERS ON IROX AND STEEL.— No. 3. 



Sir — The opinions adopted by Drs. Ure and Karsten respecting the 

 quantity of carbon in iron, namely, assigning to white cast iron a 

 larger proportion than to gray, and taking the manifestation of the 

 graphite fracture in the latter as a certain sign that the quantity of 

 carbon in the metal is on the decrease, appear to me so much at 

 variance with, and subversive of, all that practical men have under- 

 stood and believed upon this subject, that it is my intention, with 

 vour permission, to make a few remarks upon the matter, in order to 

 ascertain, by an examination of facts, how far they are borne out by 

 the appearances which we every day see exhibited on the scale of 

 manufacture, and in the manipulation of the metallurgical department 

 of the laboratory. 



I hope your readers will not consider I have travelled out of my 

 way to make any gratuitous observations on Dr. Ure's most elaborate 

 work further than the necessity of the case required, seeing his views 

 of the subject are at direct variance with my table of the proportions 

 of charcoal used in the fusion, and in forming the various qualities of 

 iron and steel so frequently referred to in these letters. 



As a prelude to the subject, and with a view to enable your readers 

 to arrive at a more clear understanding of the points at issue, I shall 

 define and class the distinct characteristics which cast iron assumes. 

 Nothing can be more marked in the page of metallurgy than those 

 divisions in the progressive stages of this metal: 



1st. Steel-grained cast-iron, or erode steel. 

 2nd. White cast iron. 

 3rd. Gray cast iron. 

 In the absence of chemical analyses, but grounded upon numerous 

 direct and comparative experiments, I have considered steel-grained 

 cast iron to contain from 1 to li percent., the white cast iron from 

 In to 2A per cent., and gray c.ist iron from 2i to 4, or, when richly 

 carburetted, to 44 or o per cent. 



Steel-grained cast iron is rarely to be met with at the blast furnaces 

 in this country : decided traces of it are occasionally to be found in 

 the commencement of a blast, particularly should the furnace be 

 started with too heavy a charge; a high temperature being required 

 to maintain its fluidity, it either sets on the bottom of the furnace, to 

 be cleared ofl' afterwards by an alloy of gray iron, or it escapes with 

 the white iion when the furnace is tapped. At this juncture, which, 

 when steel-grained iron is produced, is always one of ditKculty in the 

 afiairs of tlie furnace, should the iron which has been obtained be 

 examined, it will be found possessed of a white fracture, frequently 

 mixed with a portion of the steel-grained iron. 



Calcareous ores, however, afford the steel-grained cast iron more 

 as a natural product ; the supposed alloy of the metal of lime with 

 the iron produced from those ores, renders the white cast iron more 

 lively and fluid than the gray, and becomes in some measure a sub- 

 stitute for carbon in maintaining a considerable degree of fluidity, 

 when the metal is at any time passing into the steel-grained quality, 

 so as it may be run out cf the furnace in quantity, and with a com- 

 paratively clean cinder. 



Castings made of such iron possess a degree of strength quite 

 unknown in the general operations of the foundry ; they will beat up 

 like soft steel, and acquire by hammering a permanent flexure like 

 malleable iron ; but, as far as my information and experience go, all 

 attempts hitherto to remelt it have failed. 



Rare as this peculiar state of the metal may appear to the iron 



