MAGAZINE OF SCIENCE AND ART. 
37 
the further disadvantage of being so often compelled to 
shorten sail from the squalls that occur in the vicinity 
of the land. It is obvious, too, that every mile a ship 
is compelled to go to tho westward is a practical ad¬ 
dition of two to the distance to bo performed; for, as 
the course is eastward, after teaching the proper 
parallel of south latitude, it must necessarily be again 
run over. Tho aid of steam power won. 1 also bo found 
very serviceable in tho variable latitudes between the 
24th degree of south latitude, whore the south-east trade 
ceases, and tho 32nd, where the westerly winds usually 
begin; and again, on the Australian coast, until arrival 
in port. It is not conceived that the use of auxiliary 
steam power would bo necessary for passing tho several 
portions of tho voyage referred to, for more than 14 to 
21 days. It is not proposed, therefore, to touch anv- 
where on the passage for coals, nor to carrv a supply 
for any longer period than the latter. In a fast-sailing 
ship skilfully managed, it is confidently believed that 
the voyage to Sydney might by this means bo per¬ 
formed' with some degree of certainty in about seventy 
days. The saving of expense from "the curtailment of 
the voyage a fortnight or three weeks, especially where 
there is a considerable number of passengers, would go 
far to compensate for any additional cost that the em¬ 
ployment of steam power would occasion; and there 
can be no doubt that a vessel of this description would 
at all times command a preference for passage and 
freight over ordinary sailing ships, and would probably 
obtain much higher rates. The observations which 
have been made with referenre to the outward, apply 
with equal force to the homeward voyage. Auxiliary 
steam power would ho found highly advantageous in 
enabling a ship leaving Sydney to proceed Tapidly to 
the southward, where, as has already been pointed out, 
there is a certainty of meeting with westerly winds. 
After rounding Cape Horn, the same detention occurs 
as on the outward voyage between the 32nd and 24th 
parallels of south latitude, as well as in tho calms 
which prevail between tho 3rd and 14th degrees of north 
latitude. The vexatious delays which are also some¬ 
times experienced from adverse winds on reaching the 
Channel, wouldin like maimer be obviatedby recourse 
to steam power. If necessary, an additional supply of 
coals might be taken on board at Plymouth, to enable 
the ship to steam the whole way from "thence to London. 
Mr. Deas Thomson then proceeded to 
give some practical hints on the rigging and 
construction of the vessels to be employed 
in this service, recommending them to be 
fully rigged, fitted with screw propellers 
capable of being feathered, and constructed 
on the finest clipper lines, and of about 
1500 tons burthen. The power, he sug¬ 
gested, was to be derived from two 
cylinders of 75 nominal horse power, the 
consumption of coal for which he estimated 
at about 11 tons per day, or for 21 days 
steaming (which would be all that would 
be required on the voyage, about 231 tons 
of anthracite coal. By this means, he 
considered that the average passage from 
London to Sydney might he reduced to 70 
days, whereas at the present time it ranges 
from 90 to 100 days. 
After giving some interesting statistics 
of the runs made by the Waterloo and 
Vimiera, Mr. Deas Thomson concluded a 
very able paper by the following remarks, 
which have considerable value now, even 
under the altered circumstances, of the 
colony, with regard to steam communi¬ 
cation. 
As a mercantile speculation, it appears to me tha 
the plan suggested promises, under judicious arrange 
ments, very satisfactory results. The prospect of a 
certain and rapid passage would offer a strong induce-? 
raent to a largo majority of cabin passengers, having 
occasion to make the voyage to and from Australia, to 
proceed bv ships of this description, and to pay con-r 
siderablv higher rates of passage-money than are now 
obtained. I would recommend, however, that the 
board and accomodation should he regulated upon tho 
samo principle in all respects as in the best class of the 
present sailing-ships. Strong objections are entertained 
to tho system adopted on board some of the steamer^ 
which have hithorto been emploved in the Australian 
trade. For valuable goods, especially in cases in which 
their early arrival would bo likely to secure a kitrh 
rate of profit, or in which it was desired to obtain an 
early return of tho proceeds, greatly enhanced rates of 
freight would readily be paid. The extraordinary 
fluctuations to which the prices of various descriptions 
of goods have become liable in the Australian market 
since the discovery of gold, will, I have little doubt, 
frequently create a strong competition for freight which 
will enable the owners to demand and obtain highly 
remunerative rates. 
Mr. Deas Thomson then proceeded to 
read a paper, containing a proposal for 
combining a system of postal comnnu>i- 
cation with immigration. 
This, however, has been so entirely 
superseded by the arrangements now in 
force, that we feel sure we shall be excused 
for omitting it. 
THE SANITARY CONDITION OF SYDNEY. 
The following is tho paper on the above subject, read by 
Christopher.Kolleston, Esq., the Registrar-General, bo- 
fore the Philosophical Society, on Wednesday evening 
June 10th, 1857- 
It will bo recollected that qt tl )0 last meeting of this 
Society, in 1856, a sub-committee of the Society was 
appointed, upon the motion of Mr. Wise, to investigate 
and report upon tjie sanitary condition of the city of 
Sydney, as well a$ to consider generally the question of 
social economics, with a view to placing before the pub¬ 
lic facts, illustrative of the sanitary state and social 
progress of this city and colony. 
Press of business and other causes have intervened to 
prevent the committee then appointed from entering 
upon the enquiry, and amongst these causes the con¬ 
templated appointment of an Officer of Health, led 
them to defer taking upon themselves duties which, 
upon tho appointment of such an officer, would fall un¬ 
der his especial charge, and he carried out with greater 
precision under the sanction of municipal authority. 
It is a matter of congratulation, that, after much dis¬ 
cussion and opposition, provision was mado in the Muni¬ 
cipal Act for the appointment of this officer; and I am 
happy to find that the selection has fallen on a member 
of tins Society, one who has always shown an interest 
in its discussions, and who, I feel sure, will enter on his 
dnties with zeal, and carry them on with an earnest 
regard to tho preservation of the health and well-being 
of the citizens. 
Tho sub-committee then, haring full confidence in 
the zeal and ability of the Health Officer appointed by 
the Corporation, resign with pleasure into his hands 
the prosecution of the enquiry with which they were 
charged. 
This much I have been requested to say, on behalf 
of the mover for the committee ; and it has been sug- 
