Proposition of John Peate … John Peate made a proposition
to manufacture a large reflecting lens for the University
providing material for the same was furnished him … a committee
of 5 was appointed to take the same into consideration. R. N.
Stubbs, G. H. Humason, N. T. Arnold, G. P. Hukill, and G. B.
Chase were appointed to that committee.
Although he was 73 years old Peate was in good health and had tremendous
vitality for one his age. He had already made a number of large mirrors,
so that he could estimate the amount of time and energy he would expend
in this work. He knew that if he retained his health for the next few
years he could complete it.
With his typical planned enthusiasm he started his preparations. He wrote
to his usual supplier St. Gobain of France asking the price of a glass
blank large enough for a mirror of this size.[27] They quoted a price
of $18,000—more, obviously, than he could afford. He then canvassed the
glassmakers of Pittsburgh, the center of American glassmaking. However,
the Pittsburgh firms had little experience in optical glass, especially
of this size, and none would consider making the blank.
Having been rebuffed in Pittsburgh, he approached the Standard Plate
Glass Company of Butler, Pennsylvania. Plate glass making, at least
profitable plate glass making, was new in America and the Standard was
one of the newer companies. Moreover, it was reputed one of the best
plate glass makers in the country. Peate wrote to H. C. Tilton, general
manager of the plant, asking him for a disc of glass without bubble
or flaw 62 inches in diameter and 7 inches thick. He further advised
him that he would see him in a few days. Tilton’s experience and that
of his top supervisors was limited to the business of making ordinary
plate glass. Therefore, he sought advice as to the feasibility of this
fantastic project. He consulted George Howard, maintenance engineer of
the plant, who had graduated from Cornell only a year before. George
Howard, later to become noted as an inventor of glassmaking machinery,
was at this time simply an optimistic young engineer.
“Howard, here’s a man at Greenville who wants us to cast him a disc 62
inches in diameter and 7 inches thick. Is that possible?”
Howard calculated the cubical contents of the proposed disc and replied
that it was just barely possible. He didn’t see any particular difficulty
in it. He thought the first few attempts might fail but felt that they
could cast it successfully. Howard was later to ascribe his success more
to his optimism and ignorance, rather than to any particular innovation
he made. After being reassured by Howard, Tilton continued “Well, this
Dr. Peate is coming down here tomorrow and he wants a quotation. How much
do you think we ought to ask?”
“We’ll have some special apparatus to make and some experimenting to do.
Then we’ll probably lose two or three pots of glass. I think you’d better
ask him $800.” Howard thought that this was plenty. Tilton, however, was
more cautious and doubled the price. Peate arrived in Butler on schedule.
When Tilton named his price, Peate, of course, agreed instantly. Tilton
was somewhat shocked and probably would have been more so had he known
what St. Goubain had asked. At any rate the contract was placed with
Standard, apparently in October 1894.
Having obtained a maker for his disc Peate immediately began making
arrangements to prepare the disc. He contracted with the machine shop of
a John Hodge for the tools with which the mirror would be worked. This
small firm, The Hodge Manufacturing Co., employed only four men besides
the owner. Among these was Frank A’Hearn, then just a boy, who became
the prime source for details of the tools used by Peate in this work.
Starting in November 1894 notes such as, “worked for Dr. Peate 3½ hours”
begin to appear in his workbook.[28]
[Illustration: FIGURE 12.—Hodge’s method of cutting the checker grooves.
(From Preston, fig. 6.)]
The Hodge company made several (probably three) grinding tools for Peate.
One was about 12 inches in diameter, and was to be used by hand. Two
of the larger tools were provided with the male member of a ball and
socket joint and were to be power driven. They were 30 and 48 inches in
diameter, respectively. The largest was grooved to a waffle-like surface
on its convex face. These grooves were about ½ inch wide and 3/16 inch
deep. This pattern was ground by placing the tool face up on a wheeled
buggy, which rode on cambered oak rails. As it was pushed along the
length of the rail the grinding wheel on the radius arm cut one groove.
When the groove had been cut, the radius arm was moved 2 inches along a
line shaft and another groove cut. When all the grooves had been cut in
one direction the tool was turned 90 degrees on the buggy and the other
set of grooves was ground. The grinding of this tool took many weeks, and
making the tools and apparatus for Peate may have kept Hodge busy for
nearly six months.[29]
[Illustration: FIGURE 13.—Face of largest grinding tool made by Hodge for
Peate. (From Preston, fig. 5b.)]
The history of Peate’s 62-inch mirror probably would have remained as
obscure as that of his others except for the furor which arose over
casting the disc. The Erie Conference made no attempt to publicize this
project, and both Hodge Manufacturing and Standard Plate Glass accepted
Dr. Peate’s contracts as somewhat unusual but hardly newsworthy jobs. But
when the glass trade became aware of Standard’s intention to cast this
disc, a mighty outcry arose. Instead of encouraging Standard to complete
this novel task the _National Glass Budget_, one of the leading trade
journals, reviled them as “bumpkins” for attempting something that even
the great glassmakers of Europe would not do.
It is hard to imagine why the trade journal so strenuously objected
to Standard’s attempt. It has been suggested that it derived from the
fact that Standard Plate Glass just previous to that time had refused
to join in a combination of Pittsburgh companies which had set up a
glass trust.[30] Or it is possible that the young industry was afraid
that an overly ambitious project doomed to failure might open American
glassmaking to European ridicule and so harm the entire American
industry. Whatever the reason, the _Budget_ ridiculed Standard Plate
Glass, and later Dr. Peate, for the attempt. They argued that it could
not be done, but that if it were possible Pittsburgh would be the logical
place to try it. Criticism and unfavorable comment came from other
sources also, including “university professors from Meadville” (evidently
Allegheny College).[31] Nonetheless, Standard Plate Glass started the
project.
George Howard was in charge of the casting operation. He planned to use
the glass from a pot regularly used in the routine manufacture of plate
glass. However, certain modifications were introduced in the procedure.
The glass was to be poured on the traveling casting table, upon which was
placed a circular mold made up of two semicircles of a special charcoal
iron obtained from Philadelphia. This iron was not apt to generate
bubbles of gas when in contact with the molten glass.
The iron mold was hinged at one joint of the semicircles, and the other
joint was bolted. After the cast was poured it would be allowed to cool
somewhat. When it was judged cool enough, it would be pushed into a kiln
to be annealed. After it had remained in the kiln a certain length of
time—again based simply on judgement—a quantity of pre-heated sand was
to be poured over the mold as insulation. A further innovation was the
use of a zinc sheet placed on the underside of the mold to avoid the
possibility of trouble from grease on the casting table. This was the
initial plan of operation.
Sometime early in 1895 the first attempt was made. It was an immediate
failure. The zinc sheet, intended to protect the cast from grease,
volatilized when the molten glass was poured on it, bubbled up through
the glass, and, of course, ruined the cast.
The second attempt was evidently made sometime in March. The casting
itself was successful. Sand had been substituted for the zinc sheet.
The cast was placed in the kiln, and when it was thought to be set the
insulating sand was poured over it. After a time variously estimated at
from 4 to 11 days, the cast was considered sufficiently annealed, and was
examined.
When the sand was removed, the disc was found in fragments. There was
also a large concavity in what would have been the face of the disc.
The sand had been poured over it before the glass was sufficiently set.
However, the disc had been destroyed by its iron mold. The mold had
contracted against the disc, bending the bolt and deforming the hinges,
and this tremendous pressure had shattered the glass. The next issue
of the trade paper jubilantly noted the failures. They also included
Dr. Peate in their derision. They said in effect that at least this
experience would save the old preacher the waste of many years of time
and effort.[32]
This slur on their most esteemed citizen brought the Greenville papers
into the battle. The _Budget_ had also made the mistake of implying that
any number of Pittsburgh manufacturers were willing and able to make
the disc. John Morrison, at that time editor of the Greenville _Advance
Argus_, and source of much of our information regarding this controversy,
immediately called the bluff of the trade paper, which was able to supply
but one name, that of a George A. McBeth Company. This firm promptly
declined without qualification. Later the name of the Phillips Semner
Co. was given, and this firm guaranteed a perfect disc within 60 days
for a “remunerative price,” but would not state what this price was.[33]
Therefore Dr. Peate could not deal with the firm.
Although the hue and cry continued for a few more weeks, the battle was
really over, for Howard was soon to cast his disc. He had replaced the
iron bolts in his mold with bolts of red oak dipped in nitric acid and
then charred. The purpose of this was to relieve the strain on the glass
by having the wooden pegs break as the mold contracted.
The third cast was in the kiln and in process of being annealed when
Howard read in the _Budget_ an article that set forth the difficulties
of successfully casting optical glass. This article was anonymous and
was obviously the work of an expert; it is thought to have been written
by John Brashear.[34] Although Howard was thoroughly discouraged by this
article, the cast had already been made and no harm could be done now by
allowing it to cool and be examined.
In May 1895 Howard, with the workmen, opened the kiln. The mold was
loose, so the pegs had sheared as expected. When the sand was removed
the disc was found to be whole. A close inspection revealed no obvious
faults. The disc was gently carried to an inspection room and Dr. Peate
was immediately sent for. He arrived, examined the disc for a moment,
then said, “Give me a hammer.” Before anyone could move he seized a
nearby hatchet and knocked off the sprue, or tail left as the pot was
removed from the mold. The onlookers feared the lens would “explode,” as
predicted by its detractors, but the only result was the removal of the
tail, as Dr. Peate expected.[35]
The _Budget_ was still saying it couldn’t be done. Commenting on a May
1, 1895, announcement of the removal of the disc from the kiln, the
paper seized on the fact that the disc was still warm to predict that it
would be shattered before Peate could examine it, and reiterated its low
opinion of Standard Plate. By the time this issue was in the hands of its
readers however, the disc had been inspected and approved by Peate.
Newspapers in Pittsburgh and elsewhere carried the news of the great
American disc. The embarrassed _Budget_ replied that it was not talking
about the mere casting of the disc but the completion of the mirror. It
feigned surprise that this was all that was to be done in Butler. Even as
late as May 24, 1895, the _Butler Democratic Herald_ was still defending
its town. It concluded an editorial on the issue thus:
… we have a feeling he [The _Budget_] has set his foot in it
when he goes to poke fun at the Standard about casting the
biggest mold on earth, and the end of it may be a repetition of
the old saw “he who laughs last laughs best.”
A week before this, however, the success of this casting had been made
more or less official by an announcement to that effect in the May 17,
1895, issue of _Science_, a publication of the American Association
for the Advancement of Science and probably the most highly regarded
scientific paper of the time.
[Illustration: FIGURE 14.—Surfacing machine used by Peate. (From Preston,
fig. 4.)]
On June 1, 1895, Standard Plate rendered Peate an invoice, not for
$1600, but for $450. Evidently their work was done at cost. The disc was
now removed to Greenville where Dr. Peate had erected a shop to grind,
polish, and figure it. As the disc was slightly out of round the first
operation was to make it perfectly circular. Peate did this roughly
by spalling off pieces of the edge with his bricklayer’s hammer. The
final rounding was done with the aid of the iron hoops that had made the
mold. Dr. Peate fed steel shot between the edge of the disc and the iron
semicircles. He rotated the disc on the turntable and thus rounded it off.
After this had been done he commenced the rough grinding. Using the large
checkerboard tool, steel shot, and levigated emery Dr. Peate ground out
a rough hollow. This took only a few days. George Howard stated that the
depth of the concavity was about ⅝ inch and the shape correct to within
about 1/10,000 inch. The calculated concavity of the mirror would be
6/10 inch. Peate evidently used the usual method in polishing the large
mirror, that is, he covered the tool face with pitch and used rouge (iron
oxide) as the abrasive. This method had been used for many years before
this time and is still in use today.
The figuring, which consists of removing high spots to achieve a truly
parabolic contour, probably took the longest time to complete. A mirror
must be continually tested as this polishing is being done, and since
the polishing warms the glass and distorts its shape, it is necessary to
allow a long time for the glass to cool before it can be tested. Peate
estimated that polishing and figuring the mirror took 750 hours.[36]
We do not have a really accurate account of how he tested the mirror.
Unfortunately none of the eyewitnesses to these tests had any knowledge
of optics or of standard testing procedure. The information of those who
had such knowledge is all at least secondhand and sometimes even more
remote. J. W. Fecker, successor to Brashear,[37] who was one of a group
that examined the mirror in 1923, states that Peate did not use the knife
edge test but that he did use a pin with a hole in its head in one of the
tests used at that time.
A variety of different tests and diversions with the mirror have been
reported. Dr. Peate would entertain visitors in various ways. One of
these was to train the mirror on an apple orchard in a valley a few miles
away. In another Peate would pull out one of his whiskers and hang it
on a fence nearly a quarter of a mile away. Peate himself tells of the
time spent in testing the mirror, but does not go into detail about the
procedure. He does mention a testing table that stood about 75 feet away
from the revolving table on which the mirror rested. He says further that
the mirror was tested “in all ways known, in the shop and on a pin and a
watch dial a thousand feet distant.” Of these only the pin test seems to
have been a conventional one.[38]
After the polishing, the mirror was silvered. Said Peate: “It was
silvered and tried on the heavens in the starless region under Corvus,
and under the very imperfect management of the mirror on telescopic
stars, the report was as good as could be expected.”[39] Dr. Peate must
have spent some time testing it on the stars. The mirror was evidently
completed sometime late in summer of 1897, and when Peate was satisfied
that it was as perfect as possible, he made arrangements to send it to
American University. He also designed the shipping case to protect it
on the trip to Washington. It is described in the University paper as
follows:[40]
This consists of a box in which the glass is packed and a
wheeled truck in which it is swung. It is swung on its edge
by iron bands, which go around it over an iron belt which
encircles it.
After waiting for the case, he encountered a further delay by reason of
the fact that the express company had no office at Greenville. However
the great glass finally was loaded on the train, and on August 24, 1898,
it arrived safely at American University.
Although all parties concerned in this project seemed optimistic, no
provision for mounting the mirror had yet been made. The University paper
which announced the safe arrival of the glass hoped, at a later date,
that—
some day, we trust before long, a noble and generous giver will
appear, who will provide for the proper mounting of this mirror
and also build a worthy housing.
This donor was never to appear. Five years later, in announcing the
death of Peate, the _Courier_ was still appealing for funds to mount
the mirror. Late in 1903 it announced that a gentleman in Pennsylvania
would contribute $100,000 to defray the cost of an observatory to house
the mirror, but nothing further was ever heard of this gentleman.
Earlier, before the mirror had been made, the Reverend H. G. Sedgwick of
Nashville, Tennessee, had offered to mount and equip the mirror on the
same terms under which Peate had made it. That is, he would do the work
if someone would donate the cost and the material. But of this offer,
too, nothing further was heard. Possibly he died before the mirror was
completed.
[Illustration: FIGURE 15.—The 62-inch telescope reflector disc (USNM
310899), cast by Standard Plate Glass Company, April 20, 1895, and
figured by John Peate. It weighs 2500 pounds. Shown here as it hangs in
its protective crate, this clear green glass mirror will be a feature
of the exhibit of optics and astronomy now being prepared for the
Smithsonian’s new Museum of History and Technology, scheduled to open
soon after 1962. (_Smithsonian photo 41172_)]
The mirror was to remain untouched for some 24 years. In 1922 the
“Greenville Roundtable,” a group reportedly founded by Dr. Peate,
allocated $90 to the Reverend H. G. Dodds to investigate the disposition
of the mirror. In that same year the Erie Conference appointed Dodds a
committee of one to report on the same matter. Dodds visited American
University and conferred with the chancellors. They checked the mirror
and it seemed to be in good shape. Dodds then went to Warner and Swasey,
in Cleveland, Ohio, where he attempted to discover what it would cost
to mount the mirror and provide an observatory. But he learned nothing
there. Dodds knew nothing either of astronomy or of glass and his lack
of knowledge did not inspire confidence in his mission. He did note a
peculiar phenomenon, that people seemed suspicious of the mirror in
itself without knowing anything about its actual condition.[41]
Shortly after Dodds’ failure to secure a user for the mirror the Perkins
Observatory at Ohio Wesleyan University, which planned to add a large
reflecting telescope, became interested in it. Dr. Clifford C. Crump,
director of the Perkins Observatory, J. W. Fecker, then president of the
J. W. Fecker Company, and A. N. Finn and A. Q. Tool, of the National
Bureau of Standards, inspected the glass at American University. They
found it remarkably free of bubbles and similar defects. Due to a lack
of facilities they were unable to test the mirror optically, so that
no comment was made on either the polishing or the correctness of the
figure. It was, however, found badly strained due to poor annealing, and
Fecker advised against using it, as it would have to be re-annealed.
If this were done, some refiguring would also be necessary. After this
rather expensive renovation it would remain a rather thin, flexible glass
and not equal to modern standards. The Perkins Observatory consequently
decided rather to use a mirror cast and finished under the supervision of
the Bureau of Standards.[42]
This was the last attempt to use the mirror. It remained at American
University until the mid 30’s, when it was placed in the Smithsonian
Institution. It was still, in February 1935, the largest mirror ever cast
and polished in the United States.
Let us return now to Dr. Peate. After seeing the mirror safely stored
at American University he returned to Greenville, Pennsylvania. Then 78
years old, still in good health and very active, he was to live for 5
more years.
To the end of his life he maintained his interest in astronomy, and
was optimistic about the possibility of his great mirror eventually
being mounted and used. In 1900 at the age of 80 he decided to see
Europe once again. His prime objective on this trip was undoubtedly
the Paris Exposition of 1900, where one of the main attractions was a
huge telescope made by Gautier. It had a refracting objective of 49.2
inches, mounted horizontally, the largest refractor yet made. Strangely
enough this much publicized telescope was never used either. After the
exposition was over the backers became bankrupt and the instrument was
dismantled and sold for scrap.
Dr. Peate with his wide range of knowledge and his conversational ability
delighted and puzzled his fellow passengers on the boat to and from
Europe. They guessed that he was an educator, a scientist, or statesman
but he denied all this saying, “no, I’m only a bricklayer.”
Dr. Peate lived three years after this trip, dying on March 24, 1903.
His good health and physical vigor never left him till almost the moment
of his death; as shortly as a week before, he had conducted a funeral
service.
It would be rather easy to dismiss him as a harmless fanatic except that
everything known of him indicates that he was not. It is reasonable
to believe that his mirrors were made more in the hope than in the
certain expectation that they would stimulate the study of astronomy
in the institutions receiving them. He was probably well aware of the
difficulties of establishing so large a telescope at a newly founded
institution such as American University, and, content in the knowledge
that he had done his part, could only hope that others might be inspired
to do likewise.
Dr. Peate’s great mirror will shortly be put to use in a manner that
could hardly have been predicted by its maker. It has been in the
Smithsonian Institution for over 20 years. The huge glass will form a
part of the exhibition of optics and astronomy in the new Museum of
History and Technology that the Smithsonian Institution will open to the
public about 1962. There it will be seen by some millions of persons each
year. Because of its spectacular size it should catch the attention of
most museum visitors. Surely it will awaken in more than one potentially
able worker an interest in astronomy. If so, it will have accomplished
Dr. Peate’s purpose.