ON STEAMSHIP PERFORMANCE. 117 
only the performance of the ‘Leinster’ and Her Majesty’s yacht has been 
extracted and given in this Report. 
In studying the quantities of these mail-boats, it was found that in Report 
1861, Table IX., the nominal power of ‘ Leinster’ is given as 750, whilst in 
Report 1863 it is printed as 720. Again, in Report 1861 the diameter of 
the wheel is given as 33 feet outside the floats, and 29 feet to centre of 
journals, whilst in Report 1863 the diameter is given as 31 feet outside 
floats, and 27 feet to centre of journals—a difference therefore of 2 feet in 
each case. Further, in Report 1861 the quantities of the ‘ Leinster’ and 
‘Ulster’ are given under one bracket, leading to suppose that those two 
ships are alike in all respects, whereas such is not the case. The diameter 
of cylinders of both ships is given in that Report as 96 inches with a stroke 
of 7 feet, whilst in the Report of 1863 the diameter of cylinder of the ‘ Lein- 
ster’ is printed as 98 inches, with 6 feet 6 inches stroke, and that of the ‘ Ulster’ 
as 96 inches, with 7 feet stroke. 
In order therefore to ascertain the truth it was necessary to write to the 
manufacturer of the engines; and the correct quantities of the ‘ Leinster’ 
are given in the Table below. 
In making the condensed Report of last year, the Report on Steamship Per- 
formance of 1863 was not in the calculator’s hands, and the quantities of 
the ‘ Leinster,’ therefore, were given as he found them in former Reports ; but 
by a comparison with the Table_below the errors may be corrected. The dis- 
placement, as here given, and which was not mentioned in Report 1863, has 
been calculated from the lines. 
. Victoria and 
PERE GB Mees jee c cde sisacancteensoeeooebade sob <iios aca w Leinster. Aleck. 
RSTIST Ea E TOOL) |0.)sfensaxeciasls sp os =slec\ens-aeetdelseel 327° 300° 
PETIA LEMINELCOL | dz. cs' sp sideasebtseiisscseetesc sos 35° 40°27 
Drain ol water, In feet. c........se0e-occseoee-nee 12°68 13°92 
Area of immersed midship section............ 336° 401° 
Displacement, in tons of 35 cubic feet .. ... 1675° 1980" 
Mean immersed girth, in feet.................. 40°18 40° 
ENGINES. 
SRPEITILORINN sc salecesaraceaees ssc cseaseatelosek oe Oscillating. 
iNuimnber' of Cylinders 2. .....2s.000..1sconesereee 2 
Diameter of cylinders, in inches............... 98° 
Diameter of air-pump, in inches ............ 54° 
Stroke of cylinder, in feet ...........s..0s.0+0 6°5 
ROKG OL ALE PUINP: c.c6...eccecedoacerenescnisssine ois 
Number of revolutions, per minute ......... 26°25 25°4 
Nominal horse-POwer .........00...s0deoreseons 720° 600° 
Indicated! horse=POWwer ............csssscesesceees Acts 2980" 
Speed of vessel, in knots ...............sseeeeeee 17°747 16°827 
Speed of vessel, in statute miles ............... 20°429 19°377 
Pressure of steam by safety-valve, in lbs. ... 25° 23. 
Vacuum in condenser, in inches ............... 25° 25° 
Diameter of wheel outside float, in feet...... gine 
Diameter of wheel to journals ............... py 
