474 THE POPULAR SCIENCE MONTHLY. 



this amount of material removed from the crowns of a few high 

 hills in the vicinity would alter the landscape considerably, and 

 that this alteration, together with the turning of the Irish Sea into 

 a landlocked bay, might confuse a person acquainted with the 

 locality only as it had been before the commencement of the work. 

 The territory to be acquired for the land work would not be ex- 

 pensive, as the country on both sides is almost desert. 



It is proposed to construct two generating plants near the two 

 shores respectively, each, to be used to supply the country to which 

 it is nearest. In order not to interfere with navigation, it is sug- 

 gested to enlarge the canal of Crinan and to make a cut through 

 the isthmus of Tarbert. To the writer it does not seem that these 

 means would be better than simply to cut through the dam and 

 provide suitable locking facilities. 



One of the remarkable results which, it has been pointed out, 

 would flow from the construction of such an artificial isthmus is 

 the lowering of the level of the Irish Sea along the east coast of 

 Ireland, and thus rendering the marsh lands in that section capa- 

 ble of receiving a high degree of cultivation. 



Besides the great interest that any such plan must have in itself, 

 from the fact of the important change in the geography of the 

 British Isles which it would bring about, the results that would 

 flow from a utilization of a part of the tidal power for distribution 

 throughout the kingdom are most impressive. Our means for the 

 distribution of power electrically have developed, within the past 

 year or two even, to an extraordinary degree. Two years ago it 

 was possible to transmit electricity for lighting purposes a great 

 number of miles from the point of generation, but it was not com- 

 mercially possible so to distribute electricity for power purposes. 

 The reason for this is that in order to have electricity in a safe 

 form for use in houses, mills, or car lines it must be supplied at 

 low voltage (or electrical pressure) ; on the other hand, if we are 

 not to use an utterly prohibitive weight of copper conducting wire 

 we must transmit at high voltage. What is done, therefore, is to 

 transmit at, say, ten thousand volts and transform at the consum- 

 ing end down to anywhere from five hundred to one hundred 

 volts ; the trouble is that there is no practical way of transform- 

 ing direct currents, and until recently the alternating could not 

 be used to work commercial motors. Now, however, due largely 

 to the work of Mr. Nikola Tesla, we have motors that operate at 

 very good efficiency on alternating circuits. The methods of 

 insulation and of polyphase transmission have, moreover, been 

 improved greatly within a year or two, and these have brought 

 up the capabilities of the wire both for carrying more current 

 and working at higher voltage than was before the case. In the 

 present state of the art it would be safe for an electrical engineer 



