The San Francisco call. [volume] (San Francisco [Calif.]) 1895-1913, 1895-05-31

| that all joints and other work may be thor
oughly examined, and that the trenches shall
not be filed in until the sewer with its con-
nectlons has been fully completed for at least
one block. Some OF the recent exposures OF the
sewerage Commissioners has shown the neces-
s1ty tor some such clause in the speclhcatlons.
| 1t has been decided, also, to have concrete
base under basalt-block pavements-an al
vance IN intelligent comprehension OF the
| junction of pavementS.
more thorough supervision should be ex-
ercised over the laying of Streetcar tracks and
| also in the repair of the present roadbeds. 1t
| is the custom now after replacing the paving
stones which are removed for the purpose OF
getting at the tracks, to fill the space between
| with soft red rock and put covering OF the
| same material on the top. This rock is easily
a of e The dust Is thus made is
blown everywhere and is nuisance. The
streets are very difficult to keep clean when
! such things are allowed, and it should be
| specified that gravel should be used to fill in
| between the stones instead of red rock
i! would suggest that the specifications for
| mixing the concrete for foundations OF pave
ments be altered SO that we can really secure
| concrete and not mortar. The following ex-
tract from recent report OF the Merchants
Association will explain this: Cement is an
| almost impalpable powder and 1t is necessary
| to incorporate it well throughout the mass OF
mortar in order to secure firm bond OF the
| particles. To secure this thorough mixture II
| is customary to specify that the mixture shall
| be tamped until the water comes to the surface
as by such tamping the cement IS carried INTO
| every void.
! cit will be noticed that in the majority OF con-
| crete structures this rule is followed and that
| firm structure is the result. In laying the foun-
! dations for streets no such requirement IS eX-
! acted, and a consequence 1t is possible IN
| some instances to pick almost entirely through
the foundation with the fingers. In lhe cay Jay
| ing of the foundations the inspectors seem
| ingly believe that the tamplng is only Tor the
| purpose of getting the material into shape, ana
| therefore when it is shaped uD the tamp1ng
ceases The mixture is not then artificial stone
and as foundation is almost worthless. The
concrete foundation bears the whole weight OF
| the traffic and the bitumen is only cushloned
coat to protect it,. AS is well known, II the
| foundation fails, the bitumlnous rock 1alls
also. 1t is stated by some contractors and in
| spectors that the surface of the concrete must
| be rough, in order that the bituminous rock
| will adhere to it. Opinions differ on the sub
| Ject of the degree of roughness necessary, so
any discussion of it here is out of place. But
| venture the suggestion that the rOughness may
| be secured by running a harrow over the sur
face after the concrete is dry and before apply
ing the bltumlnous covering. The desire 10
secure a rough surface should not operate to
the extent OF making q poor job.
'The mixing should be properly performed in
order that the concrete foundation should be
one in reality. The specifications should be
changed TO read somewhat as follows: First
The rock should be screened after being brought
on the work and before mixture with the sand.
Second-The water should be applied to the
mixture through rose nozzle. tits customary
to apply the water to the mass through an or
binary nozzle or from hose without a nozzle,
the end pinched in the fingers of the attendant.
This serves to separate the materials with the
result Indt some pOrllOnS OF the 1OunQaJlOn
have more cement than necessary and other
parts wholly lacking cement. Third-The
material, when deposited in place, should be
tamped until the water rises to the surface
and makes the surface moist enough to slightly
stick to the shoe soles OF any person walking on
it. The concrete will then be properly formed
and 1t will be as difficult to pick pieces from it
when dry as 1t is now TO pick pieces from the
concrete foundation of a building"
This report was given some time ago and If
the suggestions were followed out it should
result in better work.
AS q further suggestion it might be advis-
able TO say that the present specifications for
street work should not be altered or amended
unless they have been tried with competent
men to look after the work, and that all
amendments proposed by these men be sub
mitted to some one specially fitted by educa-
ton and training to give an opinion on them
There is nothing in the way OF the Board of
Supervisors securing now complete and care
fully prepared street specifications from some
qualified man and to adopt these new specif-
cations in place of the present ones. But of
course the new specifications will not remedy
matters much unless it is agreed that no
changes shall be made except by those most
competent TO do so.
But after all the best way to secure good
streets is to agitate the matter and look sharply
after those who have it in charge. 1t is by
such means rather than by suggestions that
the improvement may be begun. Ask for good
streets and take interest in the securing of
them. Take it for granted that the public
officers are willing to give the people every
thing in their power and only want to know
what is wanted in order to grant it. In Europe
the Office of Alderman is looked upon as an
honor. 1t is not so highly regarded here and
the wonder is that under the circumstances we
have as much TO show as we have.
1t is not the province of this meeting to sug-
gest materials for paving, or methods for laying
any particular material AS some information
has been asked regarding the best form of pave
ment in use, and as to what constitutes de-
sirable pavement, have prepared few re-
marks SO that the non-technical nearer NAV
intelligently discuss the matter.
Ten points enter into the consideration of
paving material, namely--frSt cost cost of |
maintenance, ease of repairs, durability in use |
freedom from noise, freedom from dust free |
dom from decay, impermeability or freedom
from ABSORPTION, perfect foothold for horses |
and ease of traction.
Macadam is cheapest in first cost, but is ex- |
pensive to maintain; it gives out much dust, it |
and, on good macadamized road, it is easy to |
haul loads on. 1t is Objectionable principally |
because OF its wearing and dust.
Cobblestones are not to be recommended for |
anything except use between the tracks of |
horse railways. AS they are gong out of ex-
istence rapidly the day of cobblestones is pass
ing:
Wood is generally high in first cost, is easy
to repair, costly to maintain, being full OF |
joints it is not particularly healthy, as it alb
serbs moisture and retains dust. 1t is quiet |
pavement and is easy to travel on, and gives |
very good foothold for horses. Its objections |
are that 1T is not healthy and is expensive in |
maintenance.
Granite or basalt blocks form durable pave |
ment and are good on all grades. The princi- |
pal ODleCllOn 10 Cn6 use OF stone is the noise 1t
occasions. Being full of joints it is easy to re-
pair, but is not particularly healthy, the joints
also add to the noise In fact stone-block pay
ing is to be commended for only one thing
durability.
Brick is high in first cost, but low in cost of |
maintenance. 1t is easy to repair, affords good |
foothold for horses, and ease OF traction is as |
satisfactory as any pavement. 1t is, in fact |
one OF the best paving materials, and suitable |
alike for business and residence streets.
Without doubt, however, some form of |
monolithic pavement is the most satisfactory |
and asphalt and bituminOus rock pavements |
stand high in the possession of the most desir-
able qualities of pavements. Owing to their
smooth surface they are noiseiess and |
easily cleaned; they are.perfectly healthy, for
they have no joints; they are durable under |
traffic and therefore cheapiy maintained
The principal objection to these asphaltic, |
or, as some facetiously term them, .'pouitice |
pavements, is that they are not suitable for |
all grades. and their smoothness precludes per- |
feet foothold for horses when they are wet |
These are objections which are overcome by a |
careful selection OF the streets on which to use
them.
Put on each street the material which has the |
most claims for consideration for use on that |
street and keep all streets in good repair.
The concrete foundation is necessary under |
al! pavements, as tits the real street. If made |