,,american ,,society ,,of ,,civil ,,engineers ,,instituted #aheb ,,transactions ,paper ,no4 #aagc ,a ,,concrete ,,water ,,tower4,a ,,by ,a4 ,,kempkey1 ,,jr41 ,,jun4 ,,am4 ,,soc4 ,c4 ,e4,b ,,with ,,discussion ,,by ,,messrs4 ,,maurice ,c4 ,,couchot1 ,l4 ,j4 ,,mensch1 ,a4 ,h4 ,,markwart1 ,,and ,a4 ,,kempkey1 ,,jr4 ,the ,city of ,victoria is situated on the southern end of ,vancouver ,island1 in the ,province of ,british ,columbia1 ,canada1 and is the capital of the ,province4 ,in common with all cities of the extreme ,west1 its growth has been very rapid within the last few years4 ,the population of the city proper1 together with that of the municipality of ,oak ,bay1 immediately adjacent1 is now about #ce1jjj4 ,the ,victoria water-works are owned by the city and operated under the direction of a ,water ,commissioner appointed by the ,city ,council4 ,by special agreement1 water is supplied to ,oak ,bay in bulk1 this municipality having its own distributing system4 ,the rapid increase in population1 together with the fact that in recent years very little had been done toward increasing the water supply1 resulted in the necessity for remodeling the entire system1 and there are very few cities where this would involve as many complex problems or a greater variety of work4 ,water is drawn from ,elk ,lake1 situated about five miles north of the city2 thence it flows by gravity to the pumping station about four miles distant1 and from there is pumped directly to the consumers4 ,the remodeling of the system1 as recently completed1 provided for3 #a4--;,increasing the capacity of ,elk ,lake by a system of levees4 #b4--;,increasing the capacity of the main to the pumping station by replacing about two miles of the old #af-;in41 wrought-iron1 riveted pipe with #bd-;in4 riveted steel pipe4 #c4--;,increasing the capacity of the pumping station by the installation of a #d1ejj1jjj-;gal4 pumping engine of the close-connected1 cross-compound1 ,corliss1 crank-and-fly-wheel type4 #d4--,the construction of a #bj1jjj1jjj-;gal4 concrete-lined distributing reservoir in the city4 #e4--,the entire remodeling of the distributing system1 necessitating the laying of about #a_/b mile each of #ah-;in4 and #bg-;in4 pipe1 and about #a mile of #bd-;in4 riveted steel pipe2 also about #c1jjj tons of cast-iron pipe1 varying in size from #d to #ab in4 #f4--,the provision for a high-level service by means of an elevated tank of approximately #ajj1jjj gal4 capacity1 water being supplied to the tank by two electrically-driven triplex pumps1 each having a capacity of #ajj1jjj gal4 per #bd hours1 against a dynamic head of #aej ft41 and arranged to start and stop automatically with a variation of #c ft4 in the elevation of the water in the tank4 ,these pumps are located about one mile from the tower1 and are controlled by a float-operated auto-start1 in the base of the tower4 ,a description of the elevated tank1 which is novel in design1 with the reasons for adopting the type of structure used1 the method of construction1 and the detailed cost1 form the basis of this paper4 ,the tower is on the top of the highest hill in the city1 in the heart of the most exclusive residential district1 beautiful homes clustering about its base4 ,the necessity for architectural treatment of the structure is thus seen to be of prime importance4 ,in fact1 the opposition of the local residents to the ordinary type of elevated tank1 that is1 latticed columns supporting a tank with a hemispherical bottom and a conical roof1 rendered its use impossible1 although tenders were invited on such a structure4 ,it is believed that under the conditions of location1 three types of structure should be considered3 ,first1 an all-steel structure1 the ornamentation being produced by casing in with brick or concrete2 second1 a brick-and-steel1 or a concrete-and-steel1 structure1 such as the one actually erected2 third1 a typical reinforced concrete structure4 ,considering only that portion below the tank1 the amount of material required to case in a structure of the first type would be substantially the same as that used to support the tank in a structure of the second type4 ,consequently1 the steel substructure1 for all practical purposes1 would represent a dead loss1 and1 therefore1 the economy of this type is open to serious question4 ,a tender was received for a reinforced concrete structure identical in outward appearance with the one built1 but1 owing to the natural conservatism of the local residents regarding this type of construction1 it was not acceptable4 ,the tower1 as built1 consists of a hollow cylinder of plain concrete1 #aji ft4 high1 and having an inside diameter of #bb ft4 ,the walls are #aj in4 thick for the first #gj ft4 and #f in4 thick for the remaining #ci ft41 and are ornamented with six pilasters 7#gj ft4 high1 #c ft4 wide1 and #g in4 thick71 a #d-;ft4 belt1 then twelve pilasters 7#ab ft4 high1 #ah in4 wide1 and #g in4 thick71 a cornice1 and a parapet wall4 ,a steel tank of the ordinary type is embedded in the upper #dj ft4 of this cylinder4 ,to form the bottom of this tank1 a plain concrete dome is thrown across the cylinder at a point about #gj ft4 from the base1 the thrust of this dome being taken up by two steel rings1 #a_/b in4 by #ad in4 and #c_/h in4 by #ah in41 bedded into the walls of the tower1 the latter ring being riveted to the lower course of the tank4 ,the tank is covered with a roof of reinforced concrete1 #d in4 thick1 conical in shape1 and reinforced with #a_/b-;in4 twisted steel bars4 ,the design of the structure is clearly shown in ,fig4 #a4 ,the tower is built on out-cropping1 solid rock4 ,this rock was roughly stepped1 and a concrete sub-base built4 ,this sub-base consists of a hollow ring1 with an inside diameter of #bj ft41 the walls being #e ft4 thick4 ,it is about #b ft4 high on one side and #g ft4 high on the other1 and forms a level base on which the tower is built4 ,the forms for this sub-base consist of vertical lagging and circumferential ribs4 ,the lagging is of double-dressed1 #b by #c-;in4 segments1 and the ribs are of #b by #ab-;in4 segments1 #f ft4 long1 lapping past one another and securely spiked together to form complete or partial circles4 ,these ribs are #b ft4 from center to center4 ,illustration3 ,,fig4 #a4--7;,full page image7 ,,water ,,tower ,,victoria1 ,b4,c4 ,,water-,,works ,similar construction was used to form the taper base of the tower proper1 except1 of course1 that the radii of the segments forming the successive ribs decreased with the height of the rib4 ,tapered lagging was used1 being made by double dressing #b by #f-;in4 pieces to #a-c_/d by #e-ac_/af in41 and ripping on a diagonal1 thus making two staves1 #c in4 wide at one end and #b-c_/d in4 wide at the other4 ,this tapered lagging was used again on the #d-;ft4 belt and cornice forms1 the taper being turned alternately up and down4 ,illustration3 ,,fig4 #b4--;,,forms ,,for ,,water ,,tower ,,victoria1 ,b4,c4 ,the interior diameter being uniform up to the bottom of the dome1 collapsible forms were used from the beginning4 ,these forms were constructed in six large sections1 #f ft4 high1 with one small key section with wedge piece to facilitate stripping1 as shown in ,fig4 #b4 ,there were three tiers of these1 bolted end to end horizontally and to each other vertically4 ,above the taper base and except in the #d-;ft4 belt and cornice1 collapsible forms were used on the outside also4 ,there were six sections extending from column to column and six column sections1 all bolted together circumferentially and constructed as shown in ,fig4 #b4 ,three tiers of these were also bolted together both vertically and horizontally4 ,having filled the top tier1 the mode of operation was as follows3 ,all horizontal bolts in the lower inside and outside forms were removed1 as was also the small key section on the inside2 this left each section suspended to the corresponding one immediately above it by the vertical bolts before mentioned4 ,it is thus seen that in each case the center tier performed the double duty of holding the upper tier1 which was full of green concrete1 and the sections of the lower tier1 until they were hoisted up and again placed in position to be filled4 ,these lower forms were then hoisted by hand--four-part tackles being used--and placed in position on the top forms1 their bottom edges being carefully set flush with the top edge of the form already in position1 and then bolted to it4 ,on the outside1 the column forms1 and on the inside1 the wedge and key sections were set last4 ,a #c-lb4 plumb-bob on a fine line was suspended from the inner scaffold and carefully centered over a point set in the rock at the base4 ,this line was in the exact center of the tower1 and the tops of all the forms1 after each shift1 were carefully set from it by measurement1 thus keeping the structure plumb4 ,the first #bc in4 of the barrel of the tower was moulded with special outside forms1 constructed so as to form the bases of the large pilasters4 ,after eleven applications of the #f-;ft4 forms1 these #bc-;in4 sections were reversed to form the capitals1 thus making these pilasters1 #fi ft4 #aj in4 over all4 ,the forms of the #d-;ft4 belt and beading were made in twelve sections of simple segments and vertical lagging1 as shown in ,fig4 #b4 ,two sets of the outside forms were split longitudinally1 as shown in ,fig4 #b1 and used to form the small pilasters4 ,the first set was put in place1 filled1 and the concrete allowed to harden4 ,the bolts were loosened and the forms raised #e-a_/b in4 vertically1 again bolted up1 and the second set was placed in position1 bringing the top of the second set up to the bottom of the cornice4 ,the bases and capitals of the small pilasters were moulded on afterward4 ,the cornice forms are clearly shown in ,fig4 #b4 ,the small boxes separating the dentils are made of light stuff1 and tacked into the cornice forms so that1 in stripping1 they would remain in place and could be taken out separately1 in order to prevent breaking off the corners of the dentils4 ,a number of outside and inside sections were sawed in half horizontally in order to provide forms for the parapet wall4 ,the inside diameter of the tank is #h in4 greater than the inside diameter of the base4 ,two sets of inside forms were split longitudinally and opened out1 as shown in ,fig4 #b1 and another small section was added to complete the circle4 ,the remaining set was left in place to support the dome forms4 ,the dome forms were made in twelve sections1 bolted together to facilitate stripping4 ,all ribs and segments were cut to size on the ground1 put together in place1 and then covered with lagging and two-ply tar paper4 ,the lagging on the lower sharp curve was formed of a double thickness of #c_/h-;in4 spruce1 the remainder being #a by #d-;in4 pine1 sized to a uniform thickness of #g_/h in4 ,fig4 #c shows the construction of these forms and the method of putting on the lagging4 ,the roof forms were made in eight sections and bolted together to facilitate stripping4 ,all ribs and segments were cut to size on the ground1 put together in place1 and covered with #a by #d-;in4 lagging1 dressed to a uniform thickness of #g_/h in41 and two-ply tar paper4 ,fig4 #c shows the construction of these forms4 ,the segments being put in horizontally instead of square with the lagging1 gave circles instead of parabolas1 making them much easier to lay out1 and giving a form which was amply stiff4 ,the question of using an inside scaffold only was carefully considered1 but owing to the considerable amount of ornamentation on the outside1 necessitating a large number of individual forms1 it was not thought that any economy would result4 ,fig4 #d and ,figs4 #a and #b1 ,plate ,,xxiii1 show clearly the construction of the scaffolding4 ,illustration3 ,,plate ,,xxiii1 ,,fig4 #a4--,,scaffolding ,,for ,,water ,,tower4 ,illustration3 ,,plate ,,xxiii1 ,,fig4 #b4--;,,completed ,,water ,,tower4 ,all concrete was mixed wet1 in a motor-driven1 ,smith mixer1 and handled off the outside scaffold1 being sent up in wheel-barrows on the ordinary contractor's hoist and placed in the forms through an iron chute having a hopper mouth4 ,this chute was built in three sections bolted together1 either one1 two1 or three sections being used1 depending on the distance of the forms below the deck4 ,when the top of the forms reached the elevation of any deck1 the concrete was put in through the chute from the deck above4 ,the chute was light and easily shifted by the wheel-barrow men1 assisted by the man placing the concrete1 during the interval between successive wheel-barrows4 ,illustration3 ,,fig4 #c4--;,,forms ,,for ,,water ,,tower ,,victoria1 ,b4,c4 ,the concrete1 except that for the roof and parapet1 was composed of sand and broken rock1 the run of the crusher being used4 ,that for the roof and parapet was composed of sand and gravel4 ,the only reason for using gravel for the concrete of the roof was the ease with which it could be obtained in small quantities1 the supply of broken rock having been used up1 and this being the last concrete work to be done4 ,the concrete used was as follows3 #a3c3f for the sub-base and taper base2 #a3c3e for the barrel of the tower and tank casing2 and #a3b3d for the dome and roof4 ,the dome was put in at one time1 there being no joint1 the same being true of the roof4 ,vancouver ,portland cement1 manufactured on the island about #ae miles from the city1 was used throughout the work4 ,before filling1 the inside of the tank was given a plaster coat1 consisting of #a part cement to #a-c_/d parts of fine sand4 ,this proved to be insufficient to prevent leakage1 the water seeping through the dome and appearing on the outside of the structure along the line of the bottom of the rings4 ,three more coats were then applied over the entire tank1 and two additional ones over the dome and about #h ft4 up on the sides1 and1 except for one or two small spots which show just a sign of moisture1 the tank is perfectly tight4 ,the barrel of the tower was carried up to a height of #ff ft4 ,a special set of inside forms1 about #b ft4 high1 extending to the springing line of the dome1 was then put in1 and the dome forms were set up on it4 ,the idea was that this #b-;ft4 form could be knocked out piece by piece and the weight of the dome form taken on wedges to the last #f-;ft4 form1 these wedges being gradually slackened down in order to allow the dome form to settle clear of the dome4 ,as a matter of fact1 this was done1 but the dome forms1 being very tight1 did not settle1 and had to be pried off a section at a time4 ,a similar method was used for slacking down the roof forms1 with similar results4 ,after the dome forms had been put in1 the concrete was carried up approximately to the elevation of the bottom of the rings4 ,small neat cement pads were then put in and accurately leveled1 and on these the steel rings were placed1 and the steel tank was erected4 ,in order to insure a perfectly round tank1 each course was erected against wooden templates accurately centered and fastened to the inside scaffold4 ,the tank is the ordinary type of light steel1 the lower course being #c_/af-;in41 the next1 ,no4 #h ,b4 w4 gauge1 the next1 ,no4 #aj ,b4 w4 gauge1 and the remaining four1 ,no4 #ab ,b4 w4 gauge4 ,work on the foundation was started on ,august #aeth1 #aijh1 and the tower was not completed until ,april #ast1 #aiji4 ,much time was lost waiting for the delivery of the steel1 and also owing to a period of very cold weather which caused entire cessation of work for about one month4 ,the tower as completed presents a striking appearance4 ,in order to obliterate rings due to the successive application of the forms and to cover the efflorescence so common to concrete structures1 the outside was given two coats of neat cement wash applied with ordinary calcimining brushes1 and1 up to the present time1 this seems to have been very effective in accomplishing the desired result4 ,illustration3 ,,fig4 #d4--7;,full page image7 ,,scaffold ,,for ,,water ,,tower ,irregularities due to forms are unnoticeable at a distance of #bjj or #cjj ft41 and the grouting gave a very uniform color4 ,the application of two coats of cement wash cost1 for labor1 #ig4fh1 and for material1 #ae4ah1 or #a4cb per #ajj sq4 ft41 labor being at the rate of #b4be per #h hours and cement costing #b4ec per bbl4 delivered on the work4 ,the tower was designed by ,arthur ,l4 ,adams1 ,m4 ,am4 ,soc4 ,c4 ,e41 under whose direction the plans for all the work of remodeling the water-works system were prepared and executed4 ,the forms1 scaffolding1 etc41 were designed by the writer1 who was also in immediate charge of the erection4 ,tenders received for the construction of the tower covered an extremely wide range1 and indicated at once the utter lack of knowledge on the part of the bidders of the cost of a structure of this kind4 ,inasmuch as none of them had had previous experience in this class of construction1 the engineer deemed it the part of wisdom and economy to retain the construction under his immediate supervision1 and1 therefore1 the work was done by days' labor4 ,table #a gives the cost of the structure4 ,the total herein given will not coincide with the total cost as shown by the city's books1 for the reason that various items not properly chargeable to the structure itself have been omitted1 the principal ones of which are the cost of the site1 the laying of about #fjj ft4 of sewer pipe to connect with the overflow1 and considerable expense incident to the construction of a wagon road to the tower4 ,the rates of wages paid1 all being on a basis of an #h-;hour day1 were as follows3 ,common labor #b4be and #b4ej ,carpenter #d4jj ,carpenter's helper #b4ge ,boiler-maker #c4ej ,holders on #b4ej ,boiler-maker foreman #e4jj ,plasterers #f4jj ,plasterers' helpers #c4jj ,the cost of material was as follows3 ,cement1 per barrel #b4ec ,sand1 per yard #a4dg ,rock1 per yard #j4hj ,lumber1 per #a1jjj ft4 b4 m4 #ad4jj and #af4jj ,all these prices are for material delivered on the work4 ,an examination of the cost data1 as given1 will show that for the most part the unit costs are very high4 ,this is due chiefly to the continued interruption of the work1 during its later stages1 owing to bad weather1 particularly in the case of the erection of the steel tank4 ,the material cost in this case was also exceedingly high4 ,in the case of the concreting1 inability to purchase a hoist and motor and the high cost of renting the same1 together with the delays mentioned1 added greatly to the unit cost4 ,when it is considered that the cost of plastering covers that of four coats over the entire inside of the tank and three more over about one-third of it1 it does not appear so high1 especially in view of the high rate of wages paid4 ,the cost per yard for concrete alone was #be4abf1 and this is probably about #be in excess of the cost of the same class of work executed under more favorable conditions as to location1 weather conditions1 etc4 ,,table #a4--;,,cost ,,of ,,high-,,level ,,tower1 ,,victoria ,,water-,,works4 7#dab cu4 yd47 ,,total ,,cost4 ,,unit ,,cost4 ---------------------------------------- -------------------------------- ,rate per ,amount4 ,complete4 ,labor4 ,material4 hour4 ---------------------------------------- -------------------------------- ,preliminary ,work3 ,labor1 ,carpenter #j4ej #aa4jj ,labor #j4cdd #fd4id #j4bha #bdi4fg #cbe4fa #j4gij ,material #acc4fb #acc4fb #j4cbd ,forms3 ,buildings1 shifting and stripping3 ,labor1 ,carpenter #j4ej #a1hcb4ii ,labor #j4cdd #hj4he #j4bha #efc4hd #b1dgg4fh #f4jad ,material3 ,lumber #ehc4di ,hardware #cbe4ea ,miscellaneous #ac4ij #ibb4ij #b4bdj ,scaffold3 ,erecting and tearing down3 ,labor1 ,carpenter #j4ej #fic4jj ,labor #j4cdd #cej4ei #j4bha #aag4bg #a1afj4hf #b4hah ,material3 ,lumber #dhg4gg ,hardware #bjb4gi #fij4ef #a4fgf ,concreting3 ,labor #j4ej #adb4jj #j4cdd #aa4jj #j4bha #idg4ha #a1ajj4ha #b4fgb ,material3 ,rock #cag4cj ,sand #che4gb ,cement #a1eha4ig ,motor and ,hoist3 ,rental #djf4ef ,power #hc4ec #b1gce4jh #f4fch ,plastering 7#c1jjj sq4 ft473 ,labor1 ,plasterers #j4ge #aaf4ej ,labor #j4df-g_/h #ae4jj #j4cg-a_/b #aih4eb #j4bha #aje4ff #dce4fh #ad4eb per sq4 ft4 ,material3 ,sand #h4fd ,cement #ff4aj ,alum and ,potash #af4jj #ij4gd #c4be per sq4 ft4 ,cement ,wash 7#h1efj sq4 ft473 ,labor #j4dh-c_/d #ej4jj #j4bha #dg4fh #ig4fha4ad per #ajj sq ft4 ,material3 ,cement #ae4ah #ae4ah #j4ah ,windows1 doors1 and scuttle3 ,labor #j4ej #di4jj #di4jj ,material3 #a door1 #g windows1 etc4 #dg4bf #dg4bf ,equipment3 #dj of #dfa4df #ahd4eh #ahd4eh #j4ddh ,superintendence #a1bda4de #a4ejf ,steel ,tank3 ,labor1 ,carpenter #j4ej #abd4bd ,helper #j4cdd #b4ge ,boiler-makers #chb4eg ,holders on #adg4cc ,labor #dj4fa ,foreman #j4fbe #ahf4be #hhc4gej4jdda per lb4 ,material3 ,tank1 rivets1 etc4 7#bj1jjj lb47 #a1gdj4fi #j4jhge ,iron-work3 ,spiral stairway1 inlet1 and overflow pipes1 ventilator1 reinforcing steel1 etc43 ,labor1 ,machinists #j4ej #hi4ej ,helper #j4cdd #bdj4af ,labor #j4bha #ajj4gi #dcj4de ,material #a1had4ga #a1had4ga ---------------------------------------- -------------------------------- ,total #af1egh4bi ,,discussion ,,maurice ,c4 ,,couchot1 ,m4 ,,am4 ,,soc4 ,c4 ,e4 7by letter74--,it appears to the writer that in the design of this structure two features are open to criticism4 ,the first is that such a high structure was built of plain concrete without any reinforcement4 ,even if the computation of stresses did not show the necessity for steel reinforcement1 some should have been embedded in the work4 ,as a matter of fact1 the writer believes that1 with the present knowledge of the benefit of reinforced concrete1 a structure such as this should not be built without it4 ,this applies mainly to the tower below the tank4 ,the second feature1 which is still more important1 refers to the insertion of a shell of smooth steel plate to take the stresses due to the hydrostatic pressure1 and also to insure against leakage in the walls of the tank4 ,the #f-;in4 shell of plain concrete outside the steel shell1 and the #c-;in4 shell inside1 do not work together1 and are practically of no value as walls1 but are simply outside and inside linings4 ,although the designer provided lugs to insure the adhesion of the concrete to the plate1 such precaution1 in the writer's opinion1 will not prevent the separation of the concrete from the smooth steel plate1 and1 at some future time1 the water will reach and corrode the steel4 ,it would have been better to have reinforced the wall of the tank with rods1 as is generally done4 ,the full thickness would have been available1 and less plastering would have been required4 ,furthermore1 the adhesion of concrete to a smooth steel plate is of doubtful value1 for1 in reinforced concrete1 it is not the adhesion which does the work1 but the gripping of the steel by the concrete in the process of setting4 ,l4 ,j4 ,,mensch1 ,m4 ,,am4 ,,soc4 ,c4 ,e4 7by letter74--,this water-tower is probably the sightliest structure of its kind in ,north ,america2 still1 it does not look like a water-tower1 and1 from an architectural point of view1 the crown portion is faulty1 because it makes the tank appear to be much less in depth than it really is4 ,the cost of this structure far exceeds that of similar tanks in the ,united ,states4 ,the stand-pipe at ,attleboro1 #ej ft4 in diameter and #ajj ft4 high1 cost about #be1jjj4 ,several years ago the writer proposed to build an elevated tank1 #fj ft4 in diameter and #dj ft4 deep1 the bottom of which was to be #ej ft4 above the ground1 for #ba1jjj4 ,among other elevated tanks known to the writer is one having a capacity of #ajj1jjj gal41 the bottom being #fj ft4 above the ground4,c ,the total quantities of material required for this tank are given as #d1dhj cu4 ft4 of concrete1 #bc1bjj lb4 of reinforcing steel1 and #bg1fjj ft41 b4 m41 of form lumber and staging4 ,calculating at the abnormally high unit prices of #dj cents per cu4 ft4 for concrete1 #d cents per lb4 for steel1 and #ej per #a1jjj ft41 b4 m41 for lumber1 the cost of the concrete would be #a1gib1 the steel1 #ibh1 and the form lumber and staging1 #a1chj4 ,adding to this the cost of a spiral staircase1 at the high figure of #g per linear foot in height1 the total cost of this structure would be #d1eih4 ,the factor of safety used in this structure was four1 but some engineers who are not familiar with concrete construction may require a higher factor4 ,by doubling the quantities of concrete and steel1 which would mean a tensile stress in the steel of only #h1jjj lb4 per sq4 in41 and a compressive stress in the concrete of only #bbe lb4 per sq4 in41 the cost of the tank would be only #g1cah1 as compared with the #af1egh mentioned in the paper4 ,this enormous discrepancy between a good design and an amateur design1 and between day-labor work and contract work should be a lesson which consulting engineers and managers of large corporations1 who prefer their own designs and day-labor work1 should take to heart4 ,a4 ,h4 ,,markwart1 ,,assoc4 ,m4 ,,am4 ,,soc4 ,c4 ,e4 7by letter74--,it is the writer's opinion that the steel tank enclosed within the concrete of the upper cylinder1 to take up the hoop tension and presumably to provide a water-tight tower1 will not fulfill this latter requirement4 ,if a plastered surface on the dome-shaped bottom provided the necessary imperviousness1 it would seem that plastered walls would have proved satisfactory4 ,apparently1 the sheet-metal tank is intended to exclude the possibility of exterior leakage1 but it occurs to the writer that it will fail to be efficient in this particular1 because1 under pressure1 the water will force itself under the steel tank and the dome thrust rings and out to the exterior of the tower just below the tank1 thus showing that insurance against leakage is actually provided by the plastered interior surfaces and not by the sheet-metal tank1 and1 for this reason1 ordinary deformed rod reinforcement1 in the writer's opinion1 would have proved cheaper and better1 and more in line with other parts of the reinforcement4 ,mr4 ,kempkey states3 ,before filling1 the inside of the tank was given a plaster coat1 consisting of #a part cement to #a-c_/d parts of fine sand4 ,this proved to be insufficient to prevent leakage1 the water seeping through the dome and appearing on the outside of the structure along the line of the bottom of the rings4 ,three more coats were then applied over the entire tank1 and two additional ones over the dome and about #h ft4 up on the sides1 and1 except for one or two small spots which show just a sign of moisture1 the tank is perfectly tight4 ,this substantiates the writer's contention that water-tightness was actually obtained by a liberal use of cement plaster1 which would also have been true had the reinforcement been rods4 ,as a further comment1 it might be stated that a water-tight concrete for the tank could have been obtained by adding from #h to #aj of hydrated lime to the #a3b3d mixture4 ,this seems advisable in all cases where a water-tight concrete is necessary4 ,the interior plastering could then have been done as a further precaution4 ,a4 ,,kempkey1 ,,jr41 ,,jun4 ,,am4 ,,soc4 ,c4 ,e4 7by letter74--,mr4 ,couchot's statement1 that the #c-;in4 inside and outside sheets forming the tank casing do not act together1 is quite true1 and it was not expected that they would1 other than to protect the steel and form an ornamental covering for it4 ,there is certainly adhesion between concrete and steel1 even though the steel be in the form of a thin shell1 and in a structure of this kind where the steel is designed1 with a low unit stress1 to take all the strain1 and where the load is at all times quiescent1 it is difficult to see how this bond can be destroyed2 the writer feels no concern on this score4 ,mr4 ,markwart's statement1 that the steel tank enclosed within the concrete of the upper cylinder1 presumably to provide a water-tight tower1 will not fulfill this latter requirement1 is not true1 as shown by the statement in the paper that the only leakage which occurred was that which passed under the tank1 the entire remaining portion being absolutely tight4 ,the amount of leakage1 while insignificant1 was1 until remedied1 sufficient to spot the outside of the tower1 making it unsightly2 and this1 in the writer's opinion1 is just what would have happened had the tank been constructed in the ordinary manner1 with deformed bars1 except that it would have extended over more or less of the entire surface1 instead of being localized1 as was actually the case1 and would have required more instead of less plastering4 ,it is also doubtful whether the addition of hydrated lime would have produced a tight tank1 in the sense that this structure was required to be tight4 ,in the paper the writer endeavored to bring out the fact that this is one of the few instances where the sthetic design of a structure of this sort is of prime importance1 and cost a secondary consideration4 ,there is1 therefore1 no use in comparing its cost with that of a structure in no way its equal in this respect and the use of which would not have been permitted any more than the use of the ordinary type of steel structure1 even though the estimated cost were #ge less4 ,mr4 ,mensch has been pleased to term this design amateurish1 presumably because of the conservative character of the stresses used and because of its cost2 at the same time1 he sets up the design to which he makes reference as a good one simply because of its cheapness4 ,he will find the enormous discrepancy1 to which he calls attention1 accounted for by the fact that the good design would not have been tolerated because of its appearance and because of the fact that the excessively high unit stresses1 of which ,mr4 ,mensch is an exponent1 did not commend themselves either to the designer1 in common with most engineers1 or to ,victorian taste2 while the design used has proven eminently satisfactory to a more than usually conservative and discriminating community4 ,mr4 ,mensch's statement of unit costs1 even though applied to a much plainer structure1 is not calculated to inspire confidence in the soundness of his deductions in any one familiar with ,victoria conditions4 ,,footnotes3 ,footnote ,a3 ,presented at the meeting of ,march #afth1 #aiaj4 ,footnote ,b3 ,now ,assoc4 ,m4 ,am4 ,soc4 ,c4 ,e4 ,footnote ,c3 ,the ,reinforced ,concrete ,pocket ,book1 p4 #abd4